19 Feb
2007
19 Feb
'07
3:31 p.m.
Hi folks,
It always pleases me to bring some new DEC stuff into Binary Dinosaurs, but
it's even better when it's in good condition and still working nicely :)
Tonight I drove a grand total of 62 miles to
*edit* bollocks, while I was typing this the machine I was going to crow
about nuked the power to my house :)
Aaaaaanyhoo, it's a Professional 380 with RD52 and RX50 coupled to a nice
VR241 for display purposes, running P/OS 2.2. Or at least it was until the
power gave out. To be fair it hadn't been powered up for a few years so I
really should've taken it into work and started it up on the 'doesn't matter
if it blows' mains but hey ho. No magic smoke so I wonder what's up with
it.....
It came with an LA210, LVP16 plotter, several boxes of Pro manuals and loads
of P/OS disks and software distros.
In a word: nice. Unless it's going to keep nuking my mains :)
--
Adrian/Witchy
Binary Dinosaurs creator/curator
Www.binarydinosaurs.co.uk - the UK's biggest private home computer
collection?
19 Feb
19 Feb
4:11 p.m.
Hi folks,
It always pleases me to bring some new DEC stuff into Binary Dinosaurs, but
it's even better when it's in good condition and still working nicely :)
Oh, I don't knwo... A non-working machine gives you the pleasure of
tracing the fault :-)
Tonight I drove a grand total of 62 miles to
*edit* bollocks, while I was typing this the machine I was going to crow
about nuked the power to my house :)
Aaaaaanyhoo, it's a Professional 380 with RD52 and RX50 coupled to a nice
VR241 for display purposes, running P/OS 2.2. Or at least it was until the
power gave out. To be fair it hadn't been powered up for a few years so I
firstly, do you know if it's the CPU box or the monitor that's tripping
the mains?
And is it tripping the mains due to excessive current (posibly due to a
primary-side failure in the SMPSU -- good luck if that's in the VR241!),
or is it trupping it due to earth leakage (prossibly a defective mains
filter capaciotr)?
really should've taken it into work and started it
up on the 'doesn't matter
if it blows' mains but hey ho. No magic smoke so I wonder what's up with
it.....
How many tims do I have to repeat 'Never switch on a classic computer
without doing some PSU tests first' ?
-tony
5:45 p.m.
At 12:11 AM +0000 2/20/07, Tony Duell wrote:
How many tims do I have to repeat 'Never switch on
a classic computer
without doing some PSU tests first' ?
Face it Tony, someone is always going to be doing it. Don't tell me
that you've *never* done it. :^) Sometimes it's easy to forget in
the excitement of a new system.
Actually how about a clarification here. Are you saying *ALWAYS*
test the PS before turning the system? Or just when it's been idle
for a while? I do know when the time comes for me to power my
PDP-11/44 back on, I'll be testing the PS first (I've not been able
to use it for over 6 years).
Zane
--
| Zane H. Healy | UNIX Systems Administrator |
| healyzh at aracnet.com (primary) | OpenVMS Enthusiast |
| MONK::HEALYZH (DECnet) | Classic Computer Collector |
+----------------------------------+----------------------------+
| Empire of the Petal Throne and Traveller Role Playing, |
| PDP-10 Emulation and Zane's Computer Museum. |
| http://www.aracnet.com/~healyzh/ |
20 Feb
20 Feb
1:25 p.m.
At 12:11 AM +0000 2/20/07, Tony Duell wrote:
I was asking a semi-rhetroical question, OK :-)
How many tims do I have to repeat 'Never
switch on a classic computer
without doing some PSU tests first' ?
Face it Tony, someone is always going to be doing it. Don't tell me that you've *never* done it. :^) Sometimes
it's easy to forget in
I did it _once_, many years ago. That's when I learnt it was a _bad_ idea :-)
the excitement of a new system.
Actually, I don't think I've ever plugged in a newly-acquired classic
computer in the last 10 years, say, without inspecting it inside and
testing the PSU if at all possible.
Actually how about a clarification here. Are you saying *ALWAYS*
test the PS before turning the system? Or just when it's been idle
for a while? I do know when the time comes for me to power my
PDP-11/44 back on, I'll be testing the PS first (I've not been able
to use it for over 6 years).
I don;'t do it _every_ time I turn the machine on, sure...
Basically, the times I do said inspection/test are :
1) When I first get the machine
2) Adter a long time (months/years) of non-use
3) After any other work or repair in the PSU area
4) After moving the machine a significant distance (e.g. taking it to a
computer club meeting or VCF (I wish) for a demostration). Things can
shake loose and short in transit.
-tony
10:40 a.m.
On 20/2/07 00:11, "Tony Duell" <ard at p850ug1.demon.co.uk> wrote:
Oh, I don't knwo... A non-working machine gives
you the pleasure of
tracing the fault :-)
True.....only in this case there isn't an obvious fault.....
firstly, do you know if it's the CPU box or the
monitor that's tripping
the mains?
CPU box. Even when isolated and alone the PSU will run for 5 mins then
something shorts out and trips everything.
or is it trupping it due to earth leakage (prossibly a
defective mains
filter capaciotr)?
That's what I need to check, if it's anything it'll be a dodgy electrolytic
I hope. The Pro PSU has some big buggers in there :)
How many tims do I have to repeat 'Never switch on
a classic computer
without doing some PSU tests first' ?
Well, normally I do, but I was told this one was a worker. Obviously someone
fibbed! I'll try and get on it tonight, it was an education today working
out how the PSU came out of the machine....heh.....
--
Adrian/Witchy
Binary Dinosaurs creator/curator
Www.binarydinosaurs.co.uk - the UK's biggest private home computer
collection?
1:48 p.m.
firstly, do
you know if it's the CPU box or the monitor that's tripping
the mains?
CPU box. Even when isolated and alone the PSU will run for 5 mins then
something shorts out and trips everything. or is it trupping it due to earth leakage
(prossibly a defective mains
filter capaciotr)?
That's what I need to check, if it's anything it'll be a dodgy electrolytic
I hope. The Pro PSU has some big buggers in there :)
How many tims
do I have to repeat 'Never switch on a classic computer
without doing some PSU tests first' ?
Well, normally I do, but I was told this one was a worker. Obviously someone
fibbed! I'll try and get on it tonight, it was an education today working
out how the PSU came out of the machine....heh.....
2:47 p.m.
On 20/2/07 21:48, "Tony Duell" <ard at p850ug1.demon.co.uk> wrote:
THat's an odd fault. It's repeatable, yes? In
other words you turn it on,
it runs for 5 minutes, then trips the mains. You cna then power it down,
power it up again and it'll run for another 5 minutes...
Yep. Every time. I haven't timed it exactly, but it will run for minutes
then give up; last night I had enough time to start playing with DCL and
leave it for a bit while I dug a manual out. Then everything went black :)
THe mians filter caps would be plasting or metalised
paper types. I've
had them fail before, but normally they just go 'bang', emit magic smoke
and maybe blow the fuse.
Oh yes, plus the classic 'blown mains cap' smell. This one will trip and
run, trip and run.
The Pros (and the 'Bow, and Decmate II) are all
designed to come into
modules without tools. But be warned that setting up the machine out of
I know all about the 'bow and Decmate (wrt maintenance, dismantling etc) but
nothing about the Pro, today I learned lots :) Last time I used a Pro was
the late 80s as a console to a VAX 8550!
--
Adrian/Witchy
Binary Dinosaurs creator/curator
Www.binarydinosaurs.co.uk - the UK's biggest private home computer
collection?
6:40 p.m.
On 20/2/07 21:48, "Tony Duell" <ard at p850ug1.demon.co.uk> wrote:
Really odd.
My first thougth is that it is a mains filter capacitor that's breaking
down. Some of them are designed to be 'self healing' in that if the
dielectric breaks down, the current will then vapourise the metal in that
area, causing the capacitor to carry on working. Of course that was
before the days of those over-sensitive RCDs, etc.
I realyl would want to know exactly how it's tripping the mains. Perhaps
run it on a circuit that doesn't have an RCD.
I can't rememebr if this PSU uses separate filter capacitors (in which
case change them [1]), a mains filter module (I wonder if you can get the
same type still), or what.
[1] RS or Farnell sell them. Class X between live and neutral, class Y
between live or neutral and earth IIRC.
THat's an odd fault. It's repeatable,
yes? In other words you turn it on,
it runs for 5 minutes, then trips the mains. You cna then power it down,
power it up again and it'll run for another 5 minutes...
Yep. Every time. I haven't timed it exactly, but it will run for minutes
then give up; last night I had enough time to start playing with DCL and
leave it for a bit while I dug a manual out. Then everything went black :) The Pros (and
the 'Bow, and Decmate II) are all designed to come into
modules without tools. But be warned that setting up the machine out of
I know all about the 'bow and Decmate (wrt maintenance, dismantling etc) but 
7:25 p.m.
Tony Duell wrote:
My first thougth is that it is a mains filter
capacitor that's breaking
down. Some of them are designed to be 'self healing' in that if the
dielectric breaks down, the current will then vapourise the metal in that
area, causing the capacitor to carry on working. Of course that was
before the days of those over-sensitive RCDs, etc.
This is where we find there's a temperature-controlled fan or somesuch in the
machine which kicks in after a few minutes and for some reason causes the PSU
to throw a wobbly...
Agreed - weird problem.
Out of interest, if you power the machine up and then immediately power it
down normally (before it's had the chance to do so itself :) does it still
upset the house mains? Just asking as maybe that's something you haven't tried
yet...
21 Feb
21 Feb
10:43 a.m.
On 21/2/07 03:25, "Jules Richardson" <julesrichardsonuk at yahoo.co.uk>
wrote:
Out of interest, if you power the machine up and then
immediately power it
down normally (before it's had the chance to do so itself :) does it still
upset the house mains? Just asking as maybe that's something you haven't tried
yet...
Not tried that, but I wouldn't be surprised if it was fine.......
--
Adrian/Witchy
Binary Dinosaurs creator/curator
Www.binarydinosaurs.co.uk - the UK's biggest private home computer
collection?
4:08 p.m.
This is where we find there's a
temperature-controlled fan or somesuch in the
machine which kicks in after a few minutes and for some reason causes the PSU
to throw a wobbly...
I've worked on several DEC Professional machines, and none of them have
temperature-controlled fans...
-tony
10:42 a.m.
On 21/2/07 02:40, "Tony Duell" <ard at p850ug1.demon.co.uk> wrote:
I thought the PRo came apart in essentially the same way. The PSU is on
top of the shcssis and held down by a toggle clamp, isn't it?
2 toggles. I know that now, but it took some searching (and removing the
bottom cover) to discover this. ZIF sockets on the expansion boards
too....nice.
--
Adrian/Witchy
Binary Dinosaurs creator/curator
Www.binarydinosaurs.co.uk - the UK's biggest private home computer
collection?
I realyl would want to know exactly how it's
tripping the mains. Perhaps
run it on a circuit that doesn't have an RCD.
I'd love to, but in a rented house and an electronic workshop that's under
strict H&S rules I'm not going to be able to find one. Even my weekend home
has an RCD.
I can't rememebr if this PSU uses separate filter
capacitors (in which
case change them [1]), a mains filter module (I wonder if you can get the
same type still), or what.
I'll open her up tonight and see if there's anything in there that looks
upset.
[1] RS or Farnell sell them. Class X between live and
neutral, class Y
between live or neutral and earth IIRC.
I've got some :)
The Pros (and the 'Bow, and Decmate II) are all
designed to come into
modules without tools. But be warned that setting up the machine out of
I know all about the 'bow and Decmate (wrt maintenance, dismantling etc) but 
11:11 a.m.
On 21 Feb 2007 at 18:42, Adrian Graham wrote:
> I realyl would want to know exactly how it's
tripping the mains. Perhaps
> run it on a circuit that doesn't have an RCD.
You didn't say how much current the system in question normally
draws. It might be informative to take a very large incandescent
lamp (or even an electric space heater) and connect it in series with
the mains supply to the unit, provided the voltage drop across same
wasn't excessive.
When the unit failed, the breaker shouldn't trip, given that you now
have a resistance to absorb the excess current. This might give you
time to determine what's going on in the unit.
Cheers,
Chuck
11:15 a.m.
On Wednesday 21 February 2007 13:42, Adrian Graham wrote:
On 21/2/07 02:40, "Tony Duell" <ard at
p850ug1.demon.co.uk> wrote:
Assuming that an "RCD" is what we call a GFI/GFCI over here, I'd suggest
either lifting the ground, or (preferably) connecting the ground to the
neutral side of the mains (make up a sepcial adapter cord to do this),
and see if it still trips the breaker.
GFIs and old (or just "big" computers) generally don't mix well.
Pat
--
Purdue University Research Computing --- http://www.rcac.purdue.edu/
The Computer Refuge --- http://computer-refuge.org
I realyl would want to know exactly how it's
tripping the mains.
Perhaps run it on a circuit that doesn't have an RCD.
I'd love to, but in a rented house and an electronic workshop that's
under strict H&S rules I'm not going to be able to find one. Even my
weekend home has an RCD.
11:28 a.m.
On Wednesday 21 February 2007 14:15, Patrick Finnegan wrote:
On Wednesday 21 February 2007 13:42, Adrian Graham
wrote:
Err, I should add that you might want to do this to see if it still
trips the breaker. I wouldn't recommend running a machine like this
unless it's known that is has a large ground-leakage current (and of
course, I'd rather run it with ground tied to neutral than with a
lifted ground...).
Pat
--
Purdue University Research Computing --- http://www.rcac.purdue.edu/
The Computer Refuge --- http://computer-refuge.org
On 21/2/07 02:40, "Tony Duell" <ard
at p850ug1.demon.co.uk> wrote:
Assuming that an "RCD" is what we call a GFI/GFCI over here, I'd
suggest either lifting the ground, or (preferably) connecting the
ground to the neutral side of the mains (make up a sepcial adapter
cord to do this), and see if it still trips the breaker.
GFIs and old (or just "big" computers) generally don't mix well. I realyl would want to know exactly how it's
tripping the mains.
Perhaps run it on a circuit that doesn't have an RCD.
I'd love to, but in a rented house and an electronic workshop
that's under strict H&S rules I'm not going to be able to find one.
Even my weekend home has an RCD.
4:44 p.m.
On Wednesday 21 February 2007 13:42, Adrian Graham wrote:
It is. 'Residual Current Device'. The old name was ELCB (Earth Leakage
Circuit Breaker)
On 21/2/07 02:40, "Tony Duell" <ard
at p850ug1.demon.co.uk> wrote:
Assuming that an "RCD" is what we call a GFI/GFCI over here, I'd suggest
I realyl would want to know exactly how it's
tripping the mains.
Perhaps run it on a circuit that doesn't have an RCD.
I'd love to, but in a rented house and an electronic workshop that's
under strict H&S rules I'm not going to be able to find one. Even my
weekend home has an RCD. either lifting the ground, or (preferably) connecting
the ground to the
neutral side of the mains (make up a sepcial adapter cord to do this),
and see if it still trips the breaker.
NO!!! UK mains distribution is significantly different to US practice. We
don't have a sparate distribution transoformer for each house (there are
no 'pole pigs' over here). Earth and neutral are not, in general, linked
at the house's distribution board.
What I would do at this point is remove all mains filter capacitors from
the PSU -- if there are any from live to earth on the PSU PCB, desolder
them. If there';s a mains filter can, remove it and connect mains
directly to the PSU PCB (but keep the intenral circuit breaker in
circuit). If the machine works propeerly now, you'll know the problem was
due to an earth current. Then you can trace where that's coming from.
GFIs and old (or just "big" computers) generally don't mix well.
Agreed.
-tony
22 Feb
22 Feb
6:22 a.m.
Tony Duell wrote:
(there are no 'pole pigs' over here)
Is that always true? Sometimes on rural roads with just one or two houses (and
also individually on farms) I've seen pole-mounted transformers and wondered
what their function is - I'd assumed they were step-down transformers from
overhead line voltage (several KV I'd guess) to 240VAC. Or do they do some
completely different job?
9:37 a.m.
On 22 Feb 2007 at 8:22, Jules Richardson wrote:
Is that always true? Sometimes on rural roads with
just one or two houses (and
also individually on farms) I've seen pole-mounted transformers and wondered
what their function is - I'd assumed they were step-down transformers from
overhead line voltage (several KV I'd guess) to 240VAC. Or do they do some
completely different job?
Even in the US, the practice varies. There are multidrop "pole pigs"
in the cities and suburbs. When one gets out into rural areas, there
is no uniform application. For example, at the point where my
driveway meets the main road, there is a large disconnect (circuit
breaker?) box that hooks up with the buried high-voltage
distribution. The HV then continues buried alongside my driveway
into my front yard, where there's a concrete pad-mounted transformer.
The 240 VAC then continues underground to the meter and my house.
I've seen inside the disconnect box and it's a 3-wire feed, so I
assume that this allows the utility to perform load-balancing on the
phases should it become necessary.
On the other hand, the fellow across the road is powered from a
conventional "pole pig" and aerial drop.
Cheers,
Chuck
10:17 a.m.
Chuck Guzis wrote:
Even in the US, the practice varies. There are
multidrop "pole pigs"
in the cities and suburbs. When one gets out into rural areas, there
is no uniform application. For example, at the point where my
driveway meets the main road, there is a large disconnect (circuit
breaker?) box that hooks up with the buried high-voltage
distribution. The HV then continues buried alongside my driveway
into my front yard, where there's a concrete pad-mounted transformer.
The 240 VAC then continues underground to the meter and my house.
On the other hand, the fellow across the road is
powered from a
conventional "pole pig" and aerial drop.
I guess you got lucky ... you have *The Power* for any *BIG IRON* that
you collect.
10:36 a.m.
On 22 Feb 2007 at 11:17, woodelf wrote:
I guess you got lucky ... you have *The Power* for any
*BIG IRON* that
you collect.
Not quite :) "The Power" would be 480v 3 phase. I once asked about
it, and while the utlity will do it (as opposed to the city where the
utility flat out refuses to run 480/3 to residences), it wouldn't be
cheap--and I'd have some serious 'splainin' to do to my lovely wife.
Cheers,
Chuck
12:40 p.m.
Chuck Guzis wrote:
On 22 Feb 2007 at 11:17, woodelf wrote:
I'd be content with 208/3.
Peace... Sridhar
I guess you got lucky ... you have *The Power*
for any *BIG IRON* that
you collect.
Not quite :) "The Power" would be 480v 3 phase. I once asked about
it, and while the utlity will do it (as opposed to the city where the
utility flat out refuses to run 480/3 to residences), it wouldn't be
cheap--and I'd have some serious 'splainin' to do to my lovely wife. 
10:40 a.m.
Hi,
Jules Richardson said:
Tony Duell wrote:
Thay do the same job...I used to live at the end of one of these lines
in Kent. In winter the snow would often bring the lines down, and
in summer the cows would use the poles as scratching posts and push them
over - never saw an electrocuted cow though...
--
Cheers,
Stan Barr stanb at dial.pipex.com
The future was never like this!
(there are no 'pole pigs' over here)
Is that always true? Sometimes on rural roads with just one or two houses (and
also individually on farms) I've seen pole-mounted transformers and wondered
what their function is - I'd assumed they were step-down transformers from
overhead line voltage (several KV I'd guess) to 240VAC. Or do they do some
completely different job?
1:15 p.m.
Tony Duell wrote:
I think you're absoluately right. But they normally supply more than just
one house, don't they?
OK, I was a little too definite in my original statement. I should have
said 'Pole pigs are rarely used in the UK, in towns/cities (at least),
many houses are supplied from the same transformer'.
-tony
(there are no 'pole pigs' over here)
Is that always true? Sometimes on rural roads with just one or two houses (and
also individually on farms) I've seen pole-mounted transformers and wondered
what their function is - I'd assumed they were step-down transformers from
overhead line voltage (several KV I'd guess) to 240VAC. Or do they do some
completely different job?
1:46 p.m.
On Thursday 22 February 2007 16:15, Tony Duell wrote:
Around everywhere I've lived (in the US), "pole pig" transformers
usually supply more than one house as well, especially in urban areas.
About the only places they don't are for heavy industrial/commercial
buildings, or in rural areas where there's 1/4mi or more between you
and your closest neighbor...
And, I guess, multi-unit apartment buildings tend to have their own
transformer as well.
Pat
--
Purdue University Research Computing --- http://www.rcac.purdue.edu/
The Computer Refuge --- http://computer-refuge.org
Tony Duell
wrote:
I think you're absoluately right. But they normally supply more than
just one house, don't they?
OK, I was a little too definite in my original statement. I should
have said 'Pole pigs are rarely used in the UK, in towns/cities (at
least), many houses are supplied from the same transformer'. (there are no 'pole pigs' over here)
Is that always true? Sometimes on rural roads with just one or two
houses (and also individually on farms) I've seen pole-mounted
transformers and wondered what their function is - I'd assumed they
were step-down transformers from overhead line voltage (several KV
I'd guess) to 240VAC. Or do they do some completely different job?
1:56 p.m.
Tony Duell wrote:
Just checking :) You'd just got me wondering if the things that I'd seen in
the UK weren't some sort of line conditioner or at least something other than
a step-down transformer.
Tony Duell
wrote:
OK, I was a little too definite in my original statement. I should have
said 'Pole pigs are rarely used in the UK, in towns/cities (at least),
many houses are supplied from the same transformer'. (there are no 'pole pigs' over here)
... 
3:15 p.m.
Tony Duell wrote:
At my house up north, until they upgraded and added another transformer
one "pole pig" was feeding about ten houses. At teatime when everyone
turned their cookers on, line voltage sagged to about 200v...
Gordon
Tony Duell
wrote:
I think you're absoluately right. But they normally supply more than just
one house, don't they?
OK, I was a little too definite in my original statement. I should have
said 'Pole pigs are rarely used in the UK, in towns/cities (at least),
many houses are supplied from the same transformer'. (there are no 'pole pigs' over here)
Is that always true? Sometimes on rural roads with just one or two houses (and
also individually on farms) I've seen pole-mounted transformers and wondered
what their function is - I'd assumed they were step-down transformers from
overhead line voltage (several KV I'd guess) to 240VAC. Or do they do some
completely different job?
21 Feb
21 Feb
4:36 p.m.
I realyl would
want to know exactly how it's tripping the mains. Perhaps
run it on a circuit that doesn't have an RCD.
I'd love to, but in a rented house and an electronic workshop that's under
strict H&S rules I'm not going to be able to find one. Even my weekend home
has an RCD.
22 Feb
22 Feb
midnight
On 22/2/07 00:36, "Tony Duell" <ard at p850ug1.demon.co.uk> wrote:
What about running it off a _big_ isolating transformer :-)
Isn't there anywhere you cna plug it in that's not 'protected' by an RCD?
Nope, not in this day and age. Mind, I've just remembered that one of our
rental places still has an 'old' style fusewire consumer unit...hmm...... :)
--
Adrian/Witchy
Binary Dinosaurs creator/curator
Www.binarydinosaurs.co.uk - the UK's biggest private home computer
collection?
I realyl would want to know exactly how it's
tripping the mains. Perhaps
run it on a circuit that doesn't have an RCD.
I'd love to, but in a rented house and an electronic workshop that's under
strict H&S rules I'm not going to be able to find one. Even my weekend home
has an RCD. 
20 Feb
20 Feb
10:11 p.m.
On Tue, 20 Feb 2007 22:47:05 +0000, Adrian Graham wrote:
On 20/2/07 21:48, "Tony Duell" <ard at
p850ug1.demon.co.uk> wrote:
> THat's an odd fault. It's repeatable, yes?
In other words you turn it on,
> it runs for 5 minutes, then trips the mains. You cna then power it down,
> power it up again and it'll run for another 5 minutes...
Yep. Every time. I haven't timed it exactly, but it
will run for minutes
then give up; last night I had enough time to start playing with DCL and
leave it for a bit while I dug a manual out. Then everything went black :)
I had a problem like that, where I had a rack that was drawing close to the limit on a 20
amp breaker,
when I added the last system to the stack the problem began, after a few minutes of
runtime the breaker
would heat up and pop, I swaped the breaker out with a different one of the same size and
it that held just
fine. The circuit I moved the week breaker to, normally only runs 7 or 8 amps and it never
failed with the
light load.
I had a second breaker problem. After an extended power failure, I found that the circuit
would not carry
both the normal startup load with the additional of 2 large UPS's at full charge rate
on near dead batteries
during startup. Just about the time everything booted and came back up, the breaker would
have heated
up and poped. I pulled the external battery packs off, and let them charge the internal
batteries first and
then added one external pack at a time, untill I could get a larger circuit run to the
rack.
While you are at it, you might want to take a clamp on amp meter and balance the load
between phases.
You may be pulling more power on one phase. If you pull the voltage down on one side or
phase with an
unballanced load, the current load will go up and breakers will be more likely to overheat
and pop.
I was in a 3 phase box just yesterday that was running 17a, 23a, and 37a on each of the 3
phases.
The electric company bills based on the max load on any single phase, by moving about 10a
of load from
phase 3 to phase 1, we dropped the billable load the electric company sees from 37a to
27a, close to a
third. That should look good on next months electric bill.
Just a thought, back under my rock ....
The other Bob
21 Feb
21 Feb
10:48 a.m.
On 21/2/07 06:11, "Bob Bradlee" <caveguy at sbcglobal.net> wrote:
would heat up and pop, I swaped the breaker out with a
different one of the
same size and it that held just
fine. The circuit I moved the week breaker to, normally only runs 7 or 8 amps
and it never failed with the
light load.
Thing is, if it was something like that then the 32A breaker running the
upstairs ring main would pop rather than the whole house, that to me shows
more of a sudden leak to earth than anything else. It's still odd that the
Pro's own PSU breaker doesn't pop before anything else does.
While you are at it, you might want to take a clamp on
amp meter and balance
the load between phases.
13A Single phase :)
phase 3 to phase 1, we dropped the billable load the
electric company sees
from 37a to 27a, close to a
third. That should look good on next months electric bill.
Nice. Extra bonus for you next month then?
--
Adrian/Witchy
Binary Dinosaurs creator/curator
Www.binarydinosaurs.co.uk - the UK's biggest private home computer
collection?
4:39 p.m.
On 21/2/07 06:11, "Bob Bradlee" <caveguy at sbcglobal.net> wrote:
That 32A MCB and the breaker in the Pro are current-operated devices.
I'll bet the main switch is an RCD (and not current operated at all), and
what's tripping the latter is an earth leakage problem.
Thing is, some older mains filters have a fairly high earth current
anyway (one reason I don't want an RCD anywhere near the mains to my
workbench). SO there may not be an actual fault. But replaceing the
filter (or the capacitors, possibly with lower value ones) might get it
running.
The 5 minute delay is a puzzler though...
-tony
would heat up and pop, I swaped the breaker out
with a different one of the
same size and it that held just
fine. The circuit I moved the week breaker to, normally only runs 7 or 8 amps
and it never failed with the
light load.
Thing is, if it was something like that then the 32A breaker running the
upstairs ring main would pop rather than the whole house, that to me shows
more of a sudden leak to earth than anything else. It's still odd that the
Pro's own PSU breaker doesn't pop before anything else does.
5:58 p.m.
On 22 Feb 2007 at 0:39, Tony Duell wrote:
Thing is, some older mains filters have a fairly high
earth current
anyway (one reason I don't want an RCD anywhere near the mains to my
workbench). SO there may not be an actual fault. But replaceing the
filter (or the capacitors, possibly with lower value ones) might get it
run
Many pi-section line filters have capacitors connected between each
side of the mains and ground. If one were the slightest bit leaky,
it might warm up a bit and pass sufficient current to trip the (well,
we call it a Ground Fault Interrupter) RCD.
Cheers,
Chuck
6:15 p.m.
I have a slightly OT question about the UK RCDs.
Here in the US, GFIs are commonly installed on branch circuits, often
incorporated in the first receptacle of a string. I don't believe
I've ever seen a GFI as part of the main breaker. But then, perhaps
there's a practical reason for that as our home distribution is 120-0-
120 volt, so perhaps the need to detect an imbalance on either side
of the relative to neutral as well as either side relative to the
other (for 240v appliances) would make the device overly complex.
But here's my question: Given that the RCD is installed as part of
the main breaker, surely some allowance must be made for small
amounts of leakage from a number of powered devices. So how large
must the leakage current to earth/ground be before the breaker trips?
And a question for the US experts. On a 120v circuit, will a $6.00
GFI detect a leak between neutral and ground? Or is the detection
circuitry only on the high side of the line?
I hope I was somewhat clearer than mud.
Cheers,
Chuck
6:34 p.m.
Chuck Guzis wrote:
And a question for the US experts. On a 120v circuit,
will a $6.00
GFI detect a leak between neutral and ground? Or is the detection
circuitry only on the high side of the line?
I'm pretty sure it's only on the high side. They do make GFCI's that
detect on the neutral side, but if memory serves, they aren't the cheap
ones you find in giant bins in the Home Despot.
Peace... Sridhar
6:51 p.m.
On Wednesday 21 February 2007 21:34, Sridhar Ayengar wrote:
Chuck Guzis wrote:
Well, it detects the difference between the ground and neutral, so it
should detect it (in theory). However, there's usually (hopefully!) not
much voltage difference between the ground and neutral, so it's possible
that the GFI won't notice.
Pat
--
Purdue University ITAP/RCAC --- http://www.rcac.purdue.edu/
The Computer Refuge --- http://computer-refuge.org
And a question for the US experts. On a 120v
circuit, will a $6.00
GFI detect a leak between neutral and ground? Or is the detection
circuitry only on the high side of the line?
I'm pretty sure it's only on the high side. They do make GFCI's that
detect on the neutral side, but if memory serves, they aren't the
cheap ones you find in giant bins in the Home Despot. 
6:52 p.m.
On 2/21/07, Sridhar Ayengar <ploopster at gmail.com> wrote:
Chuck Guzis wrote:
If I understand this correctly (and I may not) the GFI detects an
inbalance between the current flows on the hot and neutral conductors,
and does not directly sense a current flow between hot and ground.
http://personal.cha.bellsouth.net/j/o/johngd/files/rv/gfi.pdf
And a question for the US experts. On a 120v
circuit, will a $6.00
GFI detect a leak between neutral and ground? Or is the detection
circuitry only on the high side of the line?
I'm pretty sure it's only on the high side. They do make GFCI's that
detect on the neutral side, but if memory serves, they aren't the cheap
ones you find in giant bins in the Home Despot.
Peace... Sridhar
7:07 p.m.
From: "Glen Slick" <glen.slick at
gmail.com>
On 2/21/07, Sridhar Ayengar <ploopster at gmail.com> wrote:
HI
I think you are correct. The ones I've opened have a transformer
with counter wound coils for the neutral and the hot. They then
have a sense winding on thatcore. Any differential current trips it.
Dwight
_________________________________________________________________
With tax season right around the corner, make sure to follow these few
simple tips.
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Chuck Guzis wrote:
If I understand this correctly (and I may not) the GFI detects an
inbalance between the current flows on the hot and neutral conductors,
and does not directly sense a current flow between hot and ground.
http://personal.cha.bellsouth.net/j/o/johngd/files/rv/gfi.pdf And a question for the US experts. On a 120v
circuit, will a $6.00
GFI detect a leak between neutral and ground? Or is the detection
circuitry only on the high side of the line?
I'm pretty sure it's only on the high side. They do make GFCI's that
detect on the neutral side, but if memory serves, they aren't the cheap
ones you find in giant bins in the Home Despot.
Peace... Sridhar
7:32 p.m.
On 2/21/07, Chuck Guzis <cclist at sydex.com> wrote:
Here in the US, GFIs are commonly installed on branch
circuits, often
incorporated in the first receptacle of a string.
I've seen plenty of those in bathrooms and kitchens, where the
upstream-most outlet is GCFI, and all the downstream outlets are
ordinary (but protected by the upstream one).
I don't believe I've ever seen a GFI as part
of the main breaker.
I saw some in a new-build on Monday night. They were described to me
as "bedroom GFCI". Dunno why they had to have them, but it seemed to
be a new code requirement here in Columbus, OH. These were apparently
only to bedrooms, not the living room, lighting, etc., thus the name.
Never seen them before, but there they were.
The breakers themselves were longer than the others, by 25%-50%, with
a small light-colored switch that would normally be covered by the
panel cover. I'm guessing the switch is the trip indicator. There
did not seem to be a "test" button.
And a question for the US experts. On a 120v circuit,
will a $6.00
GFI detect a leak between neutral and ground? Or is the detection
circuitry only on the high side of the line?
I do not know for a fact, but I _think_ the cheap GCFIs in the States
only have detection circuity on the high side.
-ethan
22 Feb
22 Feb
1:04 a.m.
Hi,
Chuck Guzis said:
I have a slightly OT question about the UK RCDs.
[Snip]
But here's my question: Given that the RCD is
installed as part of
the main breaker, surely some allowance must be made for small
amounts of leakage from a number of powered devices. So how large
must the leakage current to earth/ground be before the breaker trips?
RCDs work by measuring the current in both mains wires, this, of course
should the the same in both. If there is any difference (any Residual
Current) it must have leaked away somewhere else such as to earth.
UK RCDs typically will trip on a current difference of 30mA.
--
Cheers,
Stan Barr stanb at dial.pipex.com
The future was never like this!
11:50 a.m.
I have a slightly OT question about the UK RCDs.
Here in the US, GFIs are commonly installed on branch circuits, often
incorporated in the first receptacle of a string. I don't believe
Over here the RCD (or GFI, ELCB, whatecer you want to call it) comes in
at least 4 forms :
1) A mains plug (fits the normal 13A socket outlet) with a built-in RCD.
It protects againt problem with the device it's wired onto. They're
typically used for things like lawnmowers [1] where you might cut the
cable by accident
[1] The thing you use in the garden, not the low-noise radar signal
amplifier...
2) A socket outlet with a built-in RCD. This protects against faults in
the device plugged into that socekt (but not faults in devices plugged
into other sockets on the same circuit). Typically used for sockets for
outdoowr devices, anywhere where an earth fault is likely
3) An adaptor with a mains plug on one side and a socket on the other.
You plug it into a socket outlet and plug a device into it. It protects
againset faults in that device.
4) A replacemetn for the main swith to be fitted in the 'consumer unit'
(fusebox). It protects afainst problems in the whole house. Somwtimes
there's a master mains swtich that turns off all pwoer (and which is just
a switch) amd an RCD that comes after it and feeds the socket outlets.
Lighting ciecuits are then not protected by the RCD, but then dagerous
earth faults on lighting circuits are not common, and if the RCD does
trip the house is not plunged into darkness.
But here's my question: Given that the RCD is installed as part of
the main breaker, surely some allowance must be made for small
amounts of leakage from a number of powered devices. So how large
must the leakage current to earth/ground be before the breaker trips?
Normally 30mA of imbalance between live and neutral.
And a question for the US experts. On a 120v circuit, will a $6.00
GFI detect a leak between neutral and ground? Or is the detection
circuitry only on the high side of the line?
All the RCds I've seen in the UK work by measuring the imbalance in
current between live and netural, using a differential current
transformer. They will often trip on a neutral-earth fault.
-tony
1:42 p.m.
On Thursday 22 February 2007 16:26, Dave McGuire wrote:
On Feb 22, 2007, at 2:50 PM, Tony Duell wrote:
typically used for things like lawnmowers [1] where
you might cut
the cable by accident
[1] The thing you use in the garden, not the low-noise radar signal
amplifier...
In the US, we tend not to mow our gardens, but only our lawns. ;)
Pat
--
Purdue University Research Computing --- http://www.rcac.purdue.edu/
The Computer Refuge --- http://computer-refuge.org
2:49 p.m.
On 22 Feb 2007 at 16:42, Patrick Finnegan wrote:
In the US, we tend not to mow our gardens, but only
our lawns. ;)
And when we do, we employ our customary overkill. For example, a 6.5
hp gasoline-powered mulching self-propelled model for a postage-
stamp-sized front yard. Anything larger requires a riding mower,
preferably made by John Deere.
Unpowered reel-type mowers are considered to be "quaint".
For cleanup, nothing will do but a 2-cycle gasoline-powered blower
that puts out over 100 dB employed to best effect before 7 AM.
Cheers,
Chuck
3:09 p.m.
And thusly were the wise words spake by Patrick Finnegan
On Thursday 22 February 2007 16:26, Dave McGuire wrote:
On Feb 22, 2007, at 2:50 PM, Tony Duell wrote:
Unless you are playing Hover Bovver...
Cheers,
Bryan
typically used for things like lawnmowers [1]
where you might cut
the cable by accident
[1] The thing you use in the garden, not the low-noise radar signal
amplifier...
In the US, we tend not to mow our gardens, but only our lawns. ;)
3:02 p.m.
And thusly were the wise words spake by Dave McGuire
On Feb 22, 2007, at 2:50 PM, Tony Duell wrote:
Are there any other members for type soda? 8-)
Cheers,
Bryan
typically used for things like lawnmowers [1]
where you might cut the
cable by accident
[1] The thing you use in the garden, not the low-noise radar signal
amplifier...
soda -> monitor
12:06 a.m.
On 22/2/07 00:39, "Tony Duell" <ard at p850ug1.demon.co.uk> wrote:
That 32A MCB and the breaker in the Pro are
current-operated devices.
I'll bet the main switch is an RCD (and not current operated at all), and
what's tripping the latter is an earth leakage problem.
Yep, I think that too...
Thing is, some older mains filters have a fairly high
earth current
anyway (one reason I don't want an RCD anywhere near the mains to my
workbench). SO there may not be an actual fault. But replaceing the
filter (or the capacitors, possibly with lower value ones) might get it
running.
I didn't get a chance to look at it last night as I was perfecting the art
of procrastination AND looking over the NeXT motherlode I collected
yesterday afternoon. I'll have a go tonight.
--
Adrian/Witchy
Binary Dinosaurs creator/curator
Www.binarydinosaurs.co.uk - the UK's biggest private home computer
collection?
21 Feb
21 Feb
8:17 a.m.
Adrian Graham wrote:
On 20/2/07 21:48, "Tony Duell" <ard at
p850ug1.demon.co.uk> wrote:
Could it be something other than the Pro?
What other items are on that breaker?
Could you just be running too much stuff,
or could the breaker be marginal?
Many breakers don't blow immediately,
but allow a short time of slightly high
current before they blow, which is giving
you the 5 minutes.
Try unplugging some other stuff on that
breaker (fridge, water heater, other
computers, clocks, etc.) and see if that
affects the run time.
If you could wire a much lower-power breaker
between the blowing breaker and the Pro,
then you can see if it trips first.
But doesn't the pro have a built in breaker?
(Black button right next to the power cord)
I'd expect the breaker built into the Pro
should trip before it would pop your house
breaker if there was a PSU problem.
THat's an odd fault. It's repeatable,
yes? In other words you turn it on,
it runs for 5 minutes, then trips the mains. You cna then power it down,
power it up again and it'll run for another 5 minutes...
Yep. Every time. I haven't timed it exactly, but it will run for minutes
then give up; last night I had enough time to start playing with DCL and
leave it for a bit while I dug a manual out. Then everything went black :)
THe mians filter caps would be plasting or
metalised paper types. I've
had them fail before, but normally they just go 'bang', emit magic smoke
and maybe blow the fuse.
Oh yes, plus the classic 'blown mains cap' smell. This one will trip and
run, trip and run.
The Pros (and
the 'Bow, and Decmate II) are all designed to come into
modules without tools. But be warned that setting up the machine out of
I know all about the 'bow and Decmate (wrt maintenance, dismantling etc) but
nothing about the Pro, today I learned lots :) Last time I used a Pro was
the late 80s as a console to a VAX 8550!
10:38 a.m.
On 21/2/07 16:17, "Kevin Handy" <kth at srv.net> wrote:
Could it be something other than the Pro?
What other items are on that breaker?
Could you just be running too much stuff,
or could the breaker be marginal?
It's done the same on 2 different breakers, one is a 100A one running my
whole house (only a fridge, Mac Mini and hi-fi physically on) and the other
is an 80A one at work with nothing else on it.
Many breakers don't blow immediately,
but allow a short time of slightly high
current before they blow, which is giving
you the 5 minutes.
I'll have to see if I can measure the current draw from within the PSU since
I don't have a clamp meter.
But doesn't the pro have a built in breaker?
(Black button right next to the power cord)
I'd expect the breaker built into the Pro
should trip before it would pop your house
breaker if there was a PSU problem.
Well, the machine works until the pop, unless the RD52 is pulling too much
but in that case I'd expect the PSU breaker to pop first. It'd be nice to
plug the PSU into a mains analyser to see if anything shows up there too,
like a sudden big draw or short to earth or something.
--
Adrian/Witchy
Binary Dinosaurs creator/curator
Www.binarydinosaurs.co.uk - the UK's biggest private home computer
collection?
11:19 a.m.
Adrian Graham wrote:
On 21/2/07 16:17, "Kevin Handy" <kth at
srv.net> wrote:
Do you have any GFCI (RCD) devices (Ground Fault) on the
breakers? It may not be a large power draw, just some
current leaking into the ground line and tripping the GFCI.
Is there some indicator on your GFCI to indicate if it tripped?
Not sure why it would take 5 minutes to trip. Sounds like it
might be heat related.
Could it be something other than the Pro?
What other items are on that breaker?
Could you just be running too much stuff,
or could the breaker be marginal?
It's done the same on 2 different breakers, one is a 100A one running my
whole house (only a fridge, Mac Mini and hi-fi physically on) and the other
is an 80A one at work with nothing else on it.
4:35 p.m.
It's done the same on 2 different breakers, one is
a 100A one running my
whole house (only a fridge, Mac Mini and hi-fi physically on) and the other
is an 80A one at work with nothing else on it.
And the mains plug fuse doesn't blow? This does not sound like an
overcurrent fault to me. Is the 100A breaker an RCD type of thing?
(actually, it sounds like a 100A-rated RCD used as a main switch in the
consumer unit to me, those are _not_ 100A breakser and will not trip on
over-current, just on earth leakage).
[...]
Well, the machine works until the pop, unless the RD52
is pulling too much
but in that case I'd expect the PSU breaker to pop first. It'd be nice to
Actually, I'd expect the PSU to go into overcurrent shutdown mode or
something. In gneral, the input circuit breaker only trips if there's a
failure i nthePSU iteslf. Any problem with the load will shut the supply
down with no other effects
-tony
5:11 p.m.
On Wednesday 21 February 2007 19:35, Tony Duell wrote:
Yeah, I was thinking about that too.. If you're drawing enough current to
blow a 100A breaker through a system power cord (18 - 14AWG here in the
states), you'd end up with a very melty power cable.
I think it's gotta be a ground-fault that's causing Witchy's problems.
Pat
--
Purdue University ITAP/RCAC --- http://www.rcac.purdue.edu/
The Computer Refuge --- http://computer-refuge.org
It's done
the same on 2 different breakers, one is a 100A one
running my whole house (only a fridge, Mac Mini and hi-fi physically
on) and the other is an 80A one at work with nothing else on it.
And the mains plug fuse doesn't blow? This does not sound like an
overcurrent fault to me. Is the 100A breaker an RCD type of thing?
(actually, it sounds like a 100A-rated RCD used as a main switch in
the consumer unit to me, those are _not_ 100A breakser and will not
trip on over-current, just on earth leakage).
22 Feb
22 Feb
11:39 a.m.
Yeah, I was thinking about that too.. If you're
drawing enough current to
blow a 100A breaker through a system power cord (18 - 14AWG here in the
states), you'd end up with a very melty power cable.
In the UK, the standard mains plug contains a cartridge fuse in series
with the live wire (it's a 3 pin plug, polarised, so live and neutral
can't be swapped by plugginhg it in upside-down or anything). The
standard ratings for these fuses are 3A, 5A and 12A (others do exist). I
would expect most micros would be happy with a 3A plug fuse (that's over
700VA , after all).
Now, if you have several protective devices (fuses, circuit breakers) in
series, it's not always the case that the lowest-rated one blows in the
event of a fault, but in general the characteristics of the MCBs used in
house wiring are such that the plug fuse _will_ blow first in the event
of a fault in the device. The MCB is there to protect against faults in
the fixed wiring.
In this case, I would be suprised if that '100A breaker' was not a
100A-rated RCD, and that it doesn't trip on overcurrent anyway. I've
never seen a domestic wiring installation where the main switch was
anything other than either a plain on/off switch or an RCd.
I think it's gotta be a ground-fault that's causing Witchy's problems.
I am almost sure it is.
-tony
3:25 p.m.
New subject: New DEC museum entry :D (not the breaker sub-thread)
On 22/2/07 19:39, "Tony Duell" <ard at p850ug1.demon.co.uk> wrote:
Well, tonight I stripped the PSU down and there aren't any filtering caps,
at least not the X type ones I'm familiar with. Instead the mains cable
plugs into a honking big sealed tin box that terminates in a 2 inch earth
wire and 2 spade connectors that the live and neutral hook up to. Said earth
wire is bolted to the chassis and joined to a similar bolt holding the fan
to the case.
Anyone seen something like this 'mains plug in a sealed tin box' arrangement
before? The thing's got to be 4 or 5 inches by 2.5 inches so whatever goes
on in there is anyone's guess. If I was at work I may be tempted to unhook
the earth wire that's bolted to the chassis but it's there for a
reason....though normally I'd expect that to be there to ensure the psu
casing was never live.
In other news the NeXT cube I picked up yesterday in a non-working state has
a bad hard drive that's drawing too much off the PSU. Bah.
--
Adrian/Witchy
Binary Dinosaurs creator/curator
Www.binarydinosaurs.co.uk - the UK's biggest private home computer
collection?
I think
it's gotta be a ground-fault that's causing Witchy's problems.
I am almost sure it is.
4:06 p.m.
New subject: New DEC museum entry :D (not the breaker sub-thread)
Adrian Graham wrote:
Well, tonight I stripped the PSU down and there
aren't any filtering caps,
at least not the X type ones I'm familiar with. Instead the mains cable
plugs into a honking big sealed tin box that terminates in a 2 inch earth
wire and 2 spade connectors that the live and neutral hook up to. Said earth
wire is bolted to the chassis and joined to a similar bolt holding the fan
to the case.
Anyone seen something like this 'mains plug in a sealed tin box' arrangement
before? The thing's got to be 4 or 5 inches by 2.5 inches so whatever goes
on in there is anyone's guess.
Yeah, it'll contain class X or Y filter caps :-) Often the schematic for
what's inside the filter is printed on its case, but this one may well have
never had one, or it's fallen off.
It'll just be the same sort of arrangement as normally seen within a PSU, only
in a screened casing.
cheers
Jules
5:23 p.m.
New subject: New DEC museum entry :D (not the breaker sub-thread)
On Thursday 22 February 2007 18:25, Adrian Graham wrote:
On 22/2/07 19:39, "Tony Duell" <ard at
p850ug1.demon.co.uk> wrote:
Well, tonight I stripped the PSU down and there aren't any filtering
caps, at least not the X type ones I'm familiar with. Instead the
mains cable plugs into a honking big sealed tin box that terminates in
a 2 inch earth wire and 2 spade connectors that the live and neutral
hook up to. Said earth wire is bolted to the chassis and joined to a
similar bolt holding the fan to the case.
Anyone seen something like this 'mains plug in a sealed tin box'
arrangement before?
Yeah, it's a sealed (and probably potted) power-line EMI filter. It
should have some filter caps and coils in it.
Assuming the extra power-line noise you get by removing the EMI filter
isn't a problem, that's probably something that you can try bypassing,
to see if it's the source of your problem.
Pat
--
Purdue University ITAP/RCAC --- http://www.rcac.purdue.edu/
The Computer Refuge --- http://computer-refuge.org
I think
it's gotta be a ground-fault that's causing Witchy's
problems.
I am almost sure it is.
6:15 p.m.
New subject: New DEC museum entry :D (not the breaker sub-thread)
On 22/2/07 19:39, "Tony Duell" <ard at p850ug1.demon.co.uk> wrote:
Well, tonight I stripped the PSU down and there aren't any filtering caps,
at least not the X type ones I'm familiar with. Instead the mains cable
plugs into a honking big sealed tin box that terminates in a 2 inch earth
wire and 2 spade connectors that the live and neutral hook up to. Said earth
wire is bolted to the chassis and joined to a similar bolt holding the fan
to the case.
Anyone seen something like this 'mains plug in a sealed tin box' arrangement
Oh yes. That sounds like a mains filter unit. Inside there are several
capacitors and inductors. If you're very lucky there'll be a schematic
printed on the can somewhere.
I think
it's gotta be a ground-fault that's causing Witchy's problems.
I am almost sure it is. before? The thing's got to be 4 or 5 inches by 2.5
inches so whatever goes
on in there is anyone's guess. If I was at work I may be tempted to unhook
the earth wire that's bolted to the chassis but it's there for a
reason....though normally I'd expect that to be there to ensure the psu
casing was never live.
IOt may not do you any good to do that. Often the can is connected to the
mains earth anyway, the wire is just there for a 'belt and braces' aproach.
What I would do as a temporary measure is to remove that filter can
altoghter and wire a mains cable (or IEC plug) with earth to the PSU
chassis and live/neutral to the 2 spade terminals (this leaves the
breaker in-circuit, right? I don't have a Pro in front of me at the
moment, I can dig one out if need be). See if the machine still trips the
mains.
-tony
23 Feb
23 Feb
12:10 a.m.
New subject: New DEC museum entry :D (not the breaker sub-thread)
On 23/2/07 02:15, "Tony Duell" <ard at p850ug1.demon.co.uk> wrote:
Aye.
Oh yes. That sounds like a mains filter unit. Inside
there are several
capacitors and inductors. If you're very lucky there'll be a schematic
printed on the can somewhere.
I'm not lucky :) All there is is a part number and legends telling me which
is the line side and which is the load side.
before? The
thing's got to be 4 or 5 inches by 2.5 inches so whatever goes
on in there is anyone's guess. If I was at work I may be tempted to unhook
the earth wire that's bolted to the chassis but it's there for a
reason....though normally I'd expect that to be there to ensure the psu
casing was never live.
IOt may not do you any good to do that. Often the can is connected to the
mains earth anyway, the wire is just there for a 'belt and braces' aproach.
What I would do as a temporary measure is to remove
that filter can
altoghter and wire a mains cable (or IEC plug) with earth to the PSU
chassis and live/neutral to the 2 spade terminals (this leaves the
breaker in-circuit, right? I don't have a Pro in front of me at the
moment, I can dig one out if need be). See if the machine still trips the
mains.
I'll cut up an IEC wire over the weekend and bypass it with fingers most
definitely crossed.
--
Adrian/Witchy
Binary Dinosaurs creator/curator
Www.binarydinosaurs.co.uk - the UK's biggest private home computer
collection?
2:45 p.m.
New subject: New DEC museum entry :D (not the breaker sub-thread)
On 23/2/07 02:15, "Tony Duell" <ard at p850ug1.demon.co.uk> wrote:
Hang on... Isn't the mains input IEC plug part of the filter unit? In
other words all wires are on the load side? If not (that is, if there are
wires for the input side that go to a separate IEC plug), you could
temporarily disocnnect it, and replace it with a couple of bits of wire.
-tony
Oh yes. That sounds like a mains filter unit.
Inside there are several
capacitors and inductors. If you're very lucky there'll be a schematic
printed on the can somewhere.
I'm not lucky :) All there is is a part number and legends telling me which
is the line side and which is the load side.
24 Feb
24 Feb
5:16 a.m.
New subject: New DEC museum entry :D (not the breaker sub-thread)
On Fri, February 23, 2007 22:45, Tony Duell wrote:
I'm going to cut up one of the many IEC cables we've got at work and do
just that :)
--
adrian/witchy
Binary Dinosaurs creator/curator
www.binarydinosaurs.co.uk - the UKs biggest home computer collection?
I'm not
lucky :) All there is is a part number and legends telling me
which
is the line side and which is the load side.
Hang on... Isn't the mains input IEC plug part of the filter unit? In
other words all wires are on the load side? If not (that is, if there are
wires for the input side that go to a separate IEC plug), you could
temporarily disocnnect it, and replace it with a couple of bits of wire.
4:09 p.m.
New subject: New DEC museum entry :D (not the breaker sub-thread)
wires for the
input side that go to a separate IEC plug), you could
temporarily disocnnect it, and replace it with a couple of bits of wire.
I'm going to cut up one of the many IEC cables we've got at work and do
just that :) 
9:50 p.m.
New subject: New DEC museum entry :D (not the breaker sub-thread)
Tony Duell wrote:
Once again Tony weighs in with his estimable opinion of how everyone else
should behave.
I wonder how anyone can be so obtuse to the notion that other people exist
in different circumstances, make different valuations, have different
priorities and different techniques, than oneself.
Especially after repeatedly having the notion pointed out to one.
I'm going to cut up one of the many IEC cables we've got at work and do
just that :)
I am wondering how anyone on this list can exist without assort
colours/sizes of wire, and standard 'loose' cable around them. You
shouldn't have to cut up an IEC lead to get some wire...
11:21 p.m.
New subject: New DEC museum entry :D (not the breaker sub-thread)
I am wondering how anyone on this list can exist
without assort
colours/sizes of wire, and standard 'loose' cable around them. You
shouldn't have to cut up an IEC lead to get some wire...
No, but it might be the easiest and cheapest way to go about getting
a bare-leads power cord. I've got tons and tons of IEC cables; they
just keep accumulating. On the other hand, I have relatively few
high-quality (e.g. neoprene jacket) leaded power cables and I reserve
those for permanent installations.
But whacking the end off of an iEC cable for a jury rig? Sure,
without even a second thought. They're like wire coat hangers and
safety pins--they breed in the dark.
Cheers,
Chuck
25 Feb
25 Feb
12:47 p.m.
New subject: New DEC museum entry :D (not the breaker sub-thread)
I am wondering how anyone on this list can exist
without assort
colours/sizes of wire, and standard 'loose' cable around them. You
shouldn't have to cut up an IEC lead to get some wire...
No, but it might be the easiest and cheapest way to go about getting
a bare-leads power cord. I've got tons and tons of IEC cables; they just keep accumulating. On the other hand, I have
relatively few
high-quality (e.g. neoprene jacket) leaded power cables and I reserve
those for permanent installations.
But whacking the end off of an iEC cable for a jury rig? Sure,
I am not sure of the construction of the Pro PSU (I've not dug out one of
my Pros to check). You want to bypass the mains filter (taking that out
of the circuit altogether), but uyou want to keep the breaker in circuit.
If the fiter is a can with a built-in IEC plug (so the normal power cable
plugs into the filter can), then I'd disconnect the output side of the
filter and, as you say, jury-rig a mains lead to the approriate
connections. But if the filter can has wire connections on both the input
and output sides, I'd probably disconnect it and then use wires to
connect whatever was on the input side (IEC connector, breaker?) to
whatever's on the otuput side (PSU PCB?). In which case I'd just grab
some suitable wire off the reels.
-tony
1:54 p.m.
New subject: New DEC museum entry :D (not the breaker sub-thread)
On 25 Feb 2007 at 20:47, Tony Duell wrote:
You mean you don't have a 'suicide lead'
in your workshop? You know, a
mains plug to 3 well-insulated crocodile clips...
I did once and did entirely too much damage with it. I'll attach
wire leads now and wire-nut them onto a leaded power cord. I'm just
clumsy, particularly when I really need to sleep (which is getting to
be more frequent as I age, it seems).
I am not sure of the construction of the Pro PSU
(I've not dug out one of
my Pros to check).
If I recall the OP correcltly, the only wire lead from the filter was
a ground--the power-carrying leads terminated in spade lugs. A power
cord with a couple of spade-lug quick-connects should do the job just
fine.
Cheers,
Chuck
2:21 p.m.
New subject: New DEC museum entry :D (not the breaker sub-thread)
On 25/2/07 21:54, "Chuck Guzis" <cclist at sydex.com> wrote:
If I recall the OP correcltly, the only wire lead from
the filter was
a ground--the power-carrying leads terminated in spade lugs. A power
cord with a couple of spade-lug quick-connects should do the job just
fine.
Correct. Must remember to take the machine into the workshop tomorrow!
Oh, and Tony, you were the one who suggested the IEC lead in your first
message :oD
--
Adrian/Witchy
Binary Dinosaurs creator/curator
Www.binarydinosaurs.co.uk - the UK's biggest private home computer
collection?
4:06 p.m.
New subject: New DEC museum entry :D (not the breaker sub-thread)
On 25/2/07 21:54, "Chuck Guzis" <cclist at sydex.com> wrote:
So, are you saying that the filter can has blade terminals for the live
and neutral inputs/outputs?
If so, I've been known to use a couple of strips of metal,
well-insulated, of course, to bypass such things. Another idea (if your
junk box is anything like mine) is to use a double-pole switch with spade
temrals, set to the 'on' postion, as a jumper. Just make sure it can't
short to anything else.
My concern is that you don't want to bypass the internal circuit breaker,
just in case there's a fault that should trip it.
If I recall the OP correcltly, the only wire lead
from the filter was
a ground--the power-carrying leads terminated in spade lugs. A power
cord with a couple of spade-lug quick-connects should do the job just
fine.
Correct. Must remember to take the machine into the workshop tomorrow!
Oh, and Tony, you were the one who suggested the IEC lead in your first
message :oD
Oh, I probalby did, but remember I've not seen inside this PSU for a long
time...
-tony
26 Feb
26 Feb
12:03 p.m.
New subject: New DEC museum entry :D (not the breaker sub-thread)
On 26/2/07 00:06, "Tony Duell" <ard at p850ug1.demon.co.uk> wrote:
So, are you saying that the filter can has blade
terminals for the live
and neutral inputs/outputs?
It does, and it did. Today I crimped some spades onto an IEC cable, strapped
the earth to the PSU case and it ran happily all afternoon. As luck would
have it I found a mains receptacle in the spares bins that also had spades
as outputs so the can is out and the new receptacle is in. With a sheet
metal plate as a cover over the remaining hole it's business as usual :) You
can't tell it's new stuff.
My concern is that you don't want to bypass the
internal circuit breaker,
just in case there's a fault that should trip it.
Correct, and I didn't have to......marvellous.
--
Adrian/Witchy
Binary Dinosaurs creator/curator
Www.binarydinosaurs.co.uk - the UK's biggest private home computer
collection?
2:50 p.m.
New subject: New DEC museum entry :D (not the breaker sub-thread)
On 26/2/07 00:06, "Tony Duell" <ard at
p850ug1.demon.co.uk> wrote:
I would strongly recoemnd adding some mains filtering. You can buy mains
filters from places like RS and Farnell (they are not cheap, though!).
It's pretty obvious how to link one up..
Has anyone ever tried to open up one of these filter modules? Most of the
ones I've seen seem to have the cases soldered closed, so they could be
taken apart, but are the compoents potted inside?
-tony
So, are you saying that the filter can has blade
terminals for the live
and neutral inputs/outputs?
It does, and it did. Today I crimped some spades onto an IEC cable, strapped
the earth to the PSU case and it ran happily all afternoon. As luck would
have it I found a mains receptacle in the spares bins that also had spades
as outputs so the can is out and the new receptacle is in. With a sheet
metal plate as a cover over the remaining hole it's business as usual :) You
can't tell it's new stuff.
3:33 p.m.
New subject: New DEC museum entry :D (not the breaker sub-thread)
On 26/2/07 22:50, "Tony Duell" <ard at p850ug1.demon.co.uk> wrote:
Surely for the amount of times the machine will be running for any length of
time a mains filter won't be THAT necessary? I'm not thinking of running the
Pro for weeks at a time.
It does, and
it did. Today I crimped some spades onto an IEC cable, strapped
the earth to the PSU case and it ran happily all afternoon. As luck would
have it I found a mains receptacle in the spares bins that also had spades
as outputs so the can is out and the new receptacle is in. With a sheet
metal plate as a cover over the remaining hole it's business as usual :) You
can't tell it's new stuff.
I would strongly recoemnd adding some mains filtering. You can buy mains
filters from places like RS and Farnell (they are not cheap, though!).
It's pretty obvious how to link one up.. Has anyone ever tried to open up one of these filter
modules? Most of the
ones I've seen seem to have the cases soldered closed, so they could be
taken apart, but are the compoents potted inside?
This one's soldered shut so I'll probably take a saw to it just to see if it
can be rebuilt. Looks like I've just been dumped by my partner of 9 years so
I would appear to have some spare time on my hands.
Aaanyhoo......
--
Adrian/Witchy
Binary Dinosaurs creator/curator
Www.binarydinosaurs.co.uk - the UK's biggest private home computer
collection?
3:48 p.m.
New subject: New DEC museum entry :D (not the breaker sub-thread)
On 26 Feb 2007 at 23:33, Adrian Graham wrote:
This one's soldered shut so I'll probably take
a saw to it just to see if it
can be rebuilt. Looks like I've just been dumped by my partner of 9 years so
I would appear to have some spare time on my hands.
I'd tap on it a bit to see if it sounds solid-potted or if it's an
empty can (they come both ways). If it's an empty can, just pop it
into the ol' toaster-oven and sweat it open--no need to bother with a
saw.
Cheers,
Chuck
3:49 p.m.
New subject: New DEC museum entry :D (not the breaker sub-thread)
I would strongly recoemnd adding some mains filtering. You can buy mains
filters from places like RS and Farnell (they are not cheap, though!).
It's pretty obvious how to link one up..
Surely for the amount of times the machine will be running for any length of
time a mains filter won't be THAT necessary? I'm not thinking of running the
Pro for weeks at a time. Has anyone ever tried to open up one of these
filter modules? Most of the
ones I've seen seem to have the cases soldered closed, so they could be
taken apart, but are the compoents potted inside?
This one's soldered shut so I'll probably take a saw to it just to see if it
can be rebuilt. Looks like I've just been dumped
by my partner of 9 years so
I would appear to have some spare time on my hands.
I'm sorry to ehar the first part of that...
-tony
27 Feb
27 Feb
9:38 a.m.
New subject: New DEC museum entry :D (not the breaker sub-thread)
Adrian Graham wrote:
This one's soldered shut so I'll probably take
a saw to it just to see if it
can be rebuilt. Looks like I've just been dumped by my partner of 9 years so
I would appear to have some spare time on my hands.
If there is any type of "wet" capaciter in there, make sure
you are wearing eye protection, at least. You don't want to
get squirted with assorted chemicals in your eyes.
I wouldn't bother rebuilding them, they are just
line filters, and you can find them from many sources.
Some old PC power supplies, other dead equipment,
electronic supply houses, etc.
10:37 a.m.
New subject: New DEC museum entry :D (not the breaker sub-thread)
On 27/2/07 17:38, "Kevin Handy" <kth at srv.net> wrote:
If there is any type of "wet" capaciter in
there, make sure
you are wearing eye protection, at least. You don't want to
get squirted with assorted chemicals in your eyes.
I'll not bother then, other postings mention blocks of epoxy so there's no
point.
I wouldn't bother rebuilding them, they are just
line filters, and you can find them from many sources.
Some old PC power supplies, other dead equipment,
electronic supply houses, etc.
I paid more attention to the one I've fitted temporarily and it DOES have a
schematic on the top and is indeed a mains filter. Once I've made a metal
cover for the old hole nobody'll know the difference :) (The new filter is
much much smaller than the old one)
Cheers,
--
Adrian/Witchy
Binary Dinosaurs creator/curator
Www.binarydinosaurs.co.uk - the UK's biggest private home computer
collection?
11:14 a.m.
New subject: New DEC museum entry :D (not the breaker sub-thread)
On 27 Feb 2007 at 18:37, Adrian Graham wrote:
I paid more attention to the one I've fitted
temporarily and it DOES have a
schematic on the top and is indeed a mains filter. Once I've made a metal
cover for the old hole nobody'll know the difference :) (The new filter is
much much smaller than the old one)
...and it's hard to say what the old one contained (i.e., just a
couple of capacitors and inductors or more than that?).
Since you've got the real estate, I'd also check the input to the PSU
to see if any MOVs are onboard. If not, you might want to add a
couple in the extra space you've got. Cheap protection against
surges.
Food for thought,
Chuck
12:27 a.m.
New subject: New DEC museum entry :D (not the breaker sub-thread)
-----Original Message-----
From: cctalk-bounces at classiccmp.org [mailto:cctalk-bounces at classiccmp.org]
On Behalf Of Tony Duell
Sent: Monday, February 26, 2007 2:51 PM
To: cctalk at classiccmp.org
Subject: Re: New DEC museum entry :D (not the breaker sub-thread)
On 26/2/07 00:06, "Tony Duell" <ard at
p850ug1.demon.co.uk> wrote:
-snippage-
Has anyone ever tried to open up one of these filter
modules? Most of the
ones I've seen seem to have the cases soldered closed, so they could be
taken apart, but are the compoents potted inside?
-tony
The ones in the mac 21" monitors were potted inside... they were nice and
had the schematic of the filter silkscreened on the unit, but if you opened
up the metal can it was a wad of epoxy in there.
11:59 a.m.
New subject: New DEC museum entry :D (not the breaker sub-thread)
Tony Duell wrote:
Has anyone ever tried to open up one of these filter
modules? Most of the
ones I've seen seem to have the cases soldered closed, so they could be
taken apart, but are the compoents potted inside?
Yes and yes :)
I can't for the life of me remember why I took one to bits now, but I did at
some point last year. All potted inside, with no PCB or anything and
components just soldered directly together.
25 Feb
25 Feb
12:42 p.m.
New subject: New DEC museum entry :D (not the breaker sub-thread)
Tony Duell wrote:
Once again Tony weighs in with his estimable opinion of how everyone else
should behave.
Does the word 'wonmdering' have any meaning to oyu?
I'm going to cut up one of the many IEC cables we've got at work and do
just that :)
I am wondering how anyone on this list can exist without assort
colours/sizes of wire, and standard 'loose' cable around them. You
shouldn't have to cut up an IEC lead to get some wire...
I wonder how anyone can be so obtuse to the notion that other people exist
in different circumstances, make different valuations, have different
priorities and different techniques, than oneself.
Especially after repeatedly having the notion pointed out to one.
In this case the OP has repeatedly said he wants to do his own repairs
(on this, and on other machines).
-tony
4:23 p.m.
New subject: New DEC museum entry :D (not the breaker sub-thread)
Tony Duell wrote:
Does the word 'wonmdering' have any meaning to oyu?
If you would spend a brief moment actually considering what someone else says
you might notice I used the word in the next sentence, so it would be a pretty
reasonable inference it does.
Read your own words: "anyone on this list".
Regardless if the OP has repeatedly said as you say, he can still make his
own decisions as appropriate to his circumstances about where to get
some bits of wire.
Tony Duell wrote:
I am wondering how anyone on this list can exist
without assort
colours/sizes of wire, and standard 'loose' cable around them. You
shouldn't have to cut up an IEC lead to get some wire...
Once again Tony weighs in with his estimable opinion of how everyone else
should behave. I wonder how
anyone can be so obtuse to the notion that other people exist
in different circumstances, make different valuations, have different
priorities and different techniques, than oneself.
Especially after repeatedly having the notion pointed out to one.
In this case the OP has repeatedly said he wants to do his own repairs
(on this, and on other machines). How many tims do I have to repeat 'Never switch on
a classic computer
without doing some PSU tests first' ?
He might also be permitted to make his own decisions about whether or not to
plug in a machine without having to put up with the all-wise Tony Duell coming
by to slap his wrist and chastise him as one would a little child for not doing
as Tony has repeatedly said.
You still just don't get it.
4:36 p.m.
New subject: New DEC museum entry :D (not the breaker sub-thread)
I am wondering how anyone on this list can exist
without assort
colours/sizes of wire, and standard 'loose' cable around them. You
shouldn't have to cut up an IEC lead to get some wire...
"Here is my intergalactic spaceship. And, let me show you some of the
lengths of wire that I used in it." - Prof. Hughbert Farnsworth 3000
I, also, find it hard to comprehend how anybody could not have a pile of
junk. But, there ARE people who manage to function without it!
I just don't understand HOW.
26 Feb
26 Feb
2:37 p.m.
New subject: New DEC museum entry :D (not the breaker sub-thread)
I, also, find it hard to comprehend how anybody could
not have a pile of
junk. But, there ARE people who manage to function without it!
I just don't understand HOW.
I am waiting with bated breath for that geeat God of classic computing
(Brent) to flame you to.
-tony
25 Feb
25 Feb
2:43 a.m.
New subject: New DEC museum entry :D (not the breaker sub-thread)
On Sun, February 25, 2007 00:09, Tony Duell wrote:
I am wondering how anyone on this list can exist
without assort
colours/sizes of wire, and standard 'loose' cable around them. You
shouldn't have to cut up an IEC lead to get some wire...
Because I've got enough crap lying around as it is ;)
--
adrian/witchy
Binary Dinosaurs creator/curator
www.binarydinosaurs.co.uk - the UKs biggest home computer collection?
23 Feb
23 Feb
1:04 a.m.
New subject: New DEC museum entry :D (not the breaker sub-thread)
-----Original Message-----
From: cctalk-bounces at classiccmp.org [mailto:cctalk-bounces at classiccmp.org]
On Behalf Of Adrian Graham
Sent: Thursday, February 22, 2007 3:26 PM
To: General Discussion: On-Topic and Off-Topic Posts
Subject: Re: New DEC museum entry :D (not the breaker sub-thread)
-snip
Anyone seen something like this 'mains plug in a sealed tin box' arrangement
before? The thing's got to be 4 or 5 inches by 2.5 inches so whatever goes
on in there is anyone's guess. If I was at work I may be tempted to unhook
the earth wire that's bolted to the chassis but it's there for a
reason....though normally I'd expect that to be there to ensure the psu
casing was never live.
-/snip-
Apple used devices like this in their 21" monitors, I forget the model #'s ,
when I was working for a local scrapper in the seattle area, we got 30 of
these in as "dead" 28 of them were resurrected by replacing the filter units
with similarly rated units from a local parts place.
We were given the monitors as scrap, the replacement parts were $14.95 each
and we sold the monitors after making sure that was the only repairs that
they needed for $395.00 to 595.00 (the monitors were over a grand new at the
time)
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