21 Apr
2001
21 Apr
'01
7:56 p.m.
Robert, you are awesome! I would very much appreciate if you took
some pictures. I did some more experiment today and had quite strange
results. Now that I understand that the two black and the brown wires
are the three phases and the blue is null, I hooked up brown with P1,
the two black ones with P2 and blue with null. When I plugged in,
I saw the power line controll lights 2 and 3 flash up real quick and
then they were out. When I turned on the main power (T-switch) I could
measure 110 V at the auxiliary receptacles as it should be. However,
I could not find any 220 V at the round plug. I tried two variants:
with leaving protective ground open or closing it at N (I know,
this was only temporary ...) When I had protective GND on N I would
see the PL1 controll light flash tooo. But I never got any 220 V
between any of the pins on the round connector. Now this may be
because I tried with the power unit from the VAX that has some
(unknown) power problems.
The cable that connects the round
connector to the `power & logic box' has only six wires, two from each
phase. There are a number of other connections available on the round
connector, which leads me to believe it's a standard part for anumber of
different power schemes.
From the inside it looks as if each lead goes to at
least two of those
pins. This would seem reasonable as the pins themselves look
pretty
small for 800 W full power ...
Here's the fun part! Inside the `power &
logic box', all three phases (
no neutral!) follow a simple path thru a 20A 600V fuse, and then into a
full-wave bridge rectifier, DEC part number 11-26520-01. A couple of MOVs
offer some protection from transients, and yet more filtering.
Now, the good news:
It should be possible to simply apply 220 volt single phase (common dryer
power) to any two of the hot wires on the three phase plug! No neutral is
needed for the computer itself, altho any accessories plugged into the
lower power-distribution box will need one. These pose a small problem in
that they are connected to different hots to more evenly balance the load
on the three phase supply, but worst case they can be easily tied on to
one phase inside the box-- best case don't use them!
I'll be making a cable to replace the factory assembly, and rewireing the
distribution box to single phase, I believe. It should be 100% reversable.
My plan is to buy a receptacle box for the original power plug and
wire that box near my extra circuit-breaker box in the laundry /
computer room in the basement. Given that the stange behavior of the
power control lights are explained and my mistake in measuring the
round connector's voltage output is discovered, is there anything to
rewire inside the AC power box?
I wonder, are we the first ones to fire up their 6000 in their private
dwellings? BTW: has anyone noticed major interference with radios or
TVs (the label on the machine talks about it ...)
regards
-Gunther
22 Apr
22 Apr
1:54 a.m.
On Sun, 22 Apr 2001, Gunther Schadow wrote:
Yup. Parallel runs for more current capacity.
I would hazard a guess that they are trying to tell you that the
controller isn't plugged in to it, and it doesn't know what to do without
it, or perhps they're power OK leds for the three phase feed. IDK-- yet.
Robert, you are awesome! I would very much appreciate
if you took
some pictures. I did some more experiment today and had quite strange
thanks... ;) I'll grab the camera again today. The reason why you didn't
find any power at the output is that the PS is switched by a controller
(the `Power & Logic Box' I believe) external to it. There is a contactor
(relay) inside, it its the last black box the three-phase power wires go
thru before they come to the round connector. (or first after the
connector, depending on which way you go... :) This may be manually
operated by pushing down on the armature. WITH THE POWER OFF, look at it.
Either on the top, or the upper side, there will be a piece of plastic
that can be pushsed down towards the bottom of the contactor. You should
be able to measure continuity directly across from one color to the same
color with this pushed in, and open with it released. It may not be
possible to get all four contacts to close by pushing on it on the side,
so measure across all phases & the netural. You could also do this with
the PS energised, and look for voltage on the output, but this way is much
safer... (if I did it hot, I'd test at the end of the cable that connects
it to the `power & logic box'-- easier to find the right connection!)
The cable that connects the round
connector to the `power & logic box' has only six wires, two from each
phase. There are a number of other connections available on the round
connector, which leads me to believe it's a standard part for anumber of
different power schemes.
From the inside it looks as if each lead goes to
at least two of those
pins. This would seem reasonable as the pins themselves look
pretty
small for 800 W full power ... Here's the fun part! Inside the `power &
logic box', all three phases (
I'll be making a cable to replace the factory assembly, and rewireing the
distribution box to single phase, I believe. It should be 100% reversable.
My plan is to buy a receptacle box for the original power plug and
wire that box near my extra circuit-breaker box in the laundry /
computer room in the basement. Given that the stange behavior of the
power control lights are explained and my mistake in measuring the
round connector's voltage output is discovered, is there anything to
rewire inside the AC power box?
I wonder, are we the first ones to fire up their 6000 in their private
dwellings? BTW: has anyone noticed major interference with radios or
TVs (the label on the machine talks about it ...)
It'll be a week or more before I crank her over-- I have some more
pressing projects I'm in the middle of.
If there is a lot of interference coming out of it, the thing must be a
microwave oven inside-- there's more shielding in that case than I've ever
seen before. Put a cup of water in the bottom, boot it and shut down, and
see how hot it is!
regards
-Gunther
Bob
6:27 a.m.
On Sun, 22 Apr 2001, Gunther Schadow wrote:
I wonder, are we the first ones to fire up their 6000
in their private
dwellings?
Based on Geoff's page, I'd say he counts as one of the earliest if not the
first. Still, it's not so impressive as someone firing up an 11/780 or
one of the VAX 8000 series. They're true power hogs.
BTW: has anyone noticed major interference with radios
or
TVs (the label on the machine talks about it ...)
Well, I'm not opposed to building a Faraday cage for my VAX if necessary.
:-)
-brian.
--- Brian Chase | bdc(a)world.std.com | http://world.std.com/~bdc/ -----
Windows is a 16-bit operating system
so it can only go up to 64k of bugs. -- K.
9:34 a.m.
Speaking of Faraday cages, how would one go about doing this?
I'm preparing an area of my basement (directly below the breaker
box :) to be used as a computer room, and I'd like to shield it
as much as possible. Since the TV is going to be ~20 feet from
the VAXen, I'm rather concerned...
The cages I've seen are made from an expensive copper screen,
like window screen, but they are for doing FCC interference
measurements, not shielding. I can get 1/2 inch square fencing
from the look home improvement center, but it is
galvanized and
quite a bit coarser...
Comments?
Clint
On Sun, 22 Apr 2001, Brian Chase wrote:
On Sun, 22 Apr 2001, Gunther Schadow wrote:
I wonder, are we the first ones to fire up their
6000 in their private
dwellings?
Based on Geoff's page, I'd say he counts as one of the earliest if not the
first. Still, it's not so impressive as someone firing up an 11/780 or
one of the VAX 8000 series. They're true power hogs.
BTW: has anyone noticed major interference with
radios or
TVs (the label on the machine talks about it ...)
Well, I'm not opposed to building a Faraday cage for my VAX if necessary.
:-)
-brian.
--- Brian Chase | bdc(a)world.std.com | http://world.std.com/~bdc/ -----
Windows is a 16-bit operating system
so it can only go up to 64k of bugs. -- K.
10:33 a.m.
On Sun, 22 Apr 2001, Clint Wolff (VAX collector) wrote:
Speaking of Faraday cages, how would one go about doing this?
I'm preparing an area of my basement (directly below the breaker
box :) to be used as a computer room, and I'd like to shield it
as much as possible. Since the TV is going to be ~20 feet from
the VAXen, I'm rather concerned...
I'm not sure you will get all that much interference out of one, unless
you run it with the chassis open. There is a G_D awful lot of shielding
already in the chassis, which is built of thick, heavy steel...
The cages I've seen are made from an expensive copper screen,
like window screen, but they are for doing FCC interference
measurements, not shielding. I can get 1/2 inch square fencing
from the look home improvement center, but it is galvanized and
quite a bit coarser...
I doubt that would do too much-- but IANAEE. YMMV. If I were to do
something like that, I would check the local scrapyards for copper screen
(just on the off chance) and most likely use {galvanized,}steel
window-screen. Should be pretty cheap, all things considered.
Comments?
Never hurts to try. Let us know of it works out...
Clint
Bob
11:33 a.m.
On Sun, 22 Apr 2001, Robert F Schaefer wrote:
On Sun, 22 Apr 2001, Clint Wolff (VAX collector)
wrote:
> box :) to be used as a computer room, and I'd like to shield it
> as much as possible. Since the TV is going to be ~20 feet from
> the VAXen, I'm rather concerned...
I'm not sure you will get all that much
interference out of one, unless
you run it with the chassis open. There is a G_D awful lot of shielding
already in the chassis, which is built of thick, heavy steel...
Heck, most of us in this group probably generate way more RFI playing
around with high-voltage experiments like jacobs ladders and other
things that use a spark-gap; I wouldn't worry about any RFI from a
computer, even with the panels off, which is a perfectly reasonable
way to run one, as it makes troubleshooting easier. :-)
--
Copyright (C) 2001 R. D. Davis The difference between humans & other animals:
All Rights Reserved an unnatural belief that we're above Nature &
rdd(a)perqlogic.com 410-744-4900 her other creatures, using dogma to justify such
http://www.perqlogic.com/rdd beliefs and to justify much human cruelty.
7:38 p.m.
R. D. Davis drunkenly mumbled...
things that use a spark-gap; I wouldn't worry about any RFI from a
computer, even with the panels off, which is a perfectly reasonable
way to run one, as it makes troubleshooting easier. :-)
the second you put the panels on, or tighten at least one screw, things have
no option but to un-aviodably fail. it's life, it's how it works, i gave up
a long time ago. plus, they are prettier with the sides off. :)
-brian
10:43 a.m.
New subject: Faraday cages (was Re: VAX 6000 3-phase conversion (was: Re: Three Phase)
At 12:34 PM 4/22/01 -0600, Clint Wolff (VAX collector) wrote:
Speaking of Faraday cages, how would one go about doing
this?
...
The cages I've seen are made from an expensive
copper screen,
like window screen, but they are for doing FCC interference
measurements, not shielding. I can get 1/2 inch square fencing
from the look home improvement center, but it is galvanized and
quite a bit coarser...
...
Well the simple answer is you build a cage and you put your stuff in it
:-). Aluminum is actually a fine material to make them out of as long as
you don't allow the joints to get oxided up (Aluminum Oxide is an
insulator!) "Holes" in the screen have to be smaller than the wavelength of
the signal you are blocking. Thus if you are blocking microwaves (< 5mm)
then you need to have holes smaller than that in your screen. The biggest
issue we have at work with our cage is to make sure things transiting the
cage (like power cables) don't have any RFI on them. The power goes through
the cage to an isolation transformer then to the gear to help suppress that
stuff. You can also get conductive paint that works ok for just shielding.
(not tempest certified :-)
--Chuck
25 Apr
25 Apr
11:02 a.m.
On 22 Apr, Brian Chase wrote:
Still, it's not so impressive as someone firing up
an 11/780 or
one of the VAX 8000 series. They're true power hogs.
Hmmm. What about a VAX
9000? As I know, a well equiped 9k can suck more
than 30kW.
--
tschuess,
Jochen
Homepage: http://www.unixag-kl.fh-kl.de/~jkunz
8439
days inactive
8443
days old
8 comments
8 participants
participants (8)
-
bdc＠world.std.com -
cmcmanis＠mcmanis.com -
gunther＠aurora.regenstrief.org -
jkunz＠unixag-kl.fh-kl.de -
rdd＠smart.net -
rschaefe＠gcfn.org -
vaxman＠qwest.net -
wonko＠entropy.tmok.com