5 Feb
2015
5 Feb
'15
10:28 p.m.
I picked up a "large" machine* (for certain definitions of large) that's
currently configured for 220-240V; my house at the moment lacks 220V
receptacles. I was already planning to get an electrician out here to
put in some beefier wiring at some point (I have a couple of machines
that draw 15-20A off of 120V that I'd like to be able to run) but I
wasn't yet planning on doing 220V unless I have to.
(It looks like in theory it's possible to reconfigure the supply for
120V but I lack the docs to do so with any level of confidence...)
I don't know if this machine works, and I'd rather not invest in 220V
wiring quite yet unless it does. And, let's face it, I'm spoiled and I
demand instant gratification and I'd like to know as soon as possible if
this machine is a basket case or not.
So: since all this stuff is in the basement, I'm just about 15 feet
away from the dryer, which at first glance runs off an outlet that meets
my needs. I even have a NEMA 10-30p plug here that I could wire up to
the existing power cable for the computer. But looking into it I have
doubts that it's actually that simple; in particular since this house
was built well before 1996 and so the outlet is not grounded; there's a
neutral lug and two hot lugs (I assume two 120V A/C lines out of phase?)
and I'm guessing that might not sit well with the power supply in this
computer.
But then, I'm a rank amateur when it comes to house wiring and A/C and
power supplies and all of that so I thought I'd ask the cctalk
collective whether this can be made to work or if I should simply wait
for a professional to take care of it...
Thanks as always,
Josh
* An AMT DAP 610, if you must ask. It's an array processor from the
late 80s, with 64x64 1-bit processors. If the machine doesn't run I'm
pretty much SOL for spare parts, schematics, service manuals, or
anything beyond customer-level documentation (which I've recently
scanned, btw, if anyone's curious...)
5 Feb
5 Feb
10:59 p.m.
What you're describing seems perfect to me, power-wise. I use that sort
of 220 setup for arc welders and such.
( ### Before trying test below, keep one hand in pocket if you're new at
this - don't risk getting one leg of mains power through each hand and
across your heart, which can make it stop ### )
When you put your meter across the two hot wires, do you get something
in the 220 to 240 AC volts range? If yes (obviously dryer wouldn't run,
otherwise), you're good and that would pretty much be your answer. For
extra safety, plug the meter probes in with the breaker off, then turn
breaker on and read it so you don't ever have to touch anything dangerous.
If you're reading 220-240 and you want to go forward with testing the
computer, I guess the lack of chassis grounding you're describing could be
an annoyance, but if you have good old steel pipe for your water service,
you could just ground the chassis to that with a clamp for a quick power-up
test.
Then if your machine's ok, get the electrician in there and have it set up
to code.
Since I'm not an electrician, I'd wait for a little more corroboration
than just my $0.02, though. My level of training is "back-yard" at best.
--jake
On Thu, Feb 5, 2015 at 10:28 PM, Josh Dersch <derschjo at gmail.com> wrote:
I picked up a "large" machine* (for certain
definitions of large) that's
currently configured for 220-240V; my house at the moment lacks 220V
receptacles. I was already planning to get an electrician out here to put
in some beefier wiring at some point (I have a couple of machines that draw
15-20A off of 120V that I'd like to be able to run) but I wasn't yet
planning on doing 220V unless I have to.
(It looks like in theory it's possible to reconfigure the supply for 120V
but I lack the docs to do so with any level of confidence...)
I don't know if this machine works, and I'd rather not invest in 220V
wiring quite yet unless it does. And, let's face it, I'm spoiled and I
demand instant gratification and I'd like to know as soon as possible if
this machine is a basket case or not.
So: since all this stuff is in the basement, I'm just about 15 feet away
from the dryer, which at first glance runs off an outlet that meets my
needs. I even have a NEMA 10-30p plug here that I could wire up to the
existing power cable for the computer. But looking into it I have doubts
that it's actually that simple; in particular since this house was built
well before 1996 and so the outlet is not grounded; there's a neutral lug
and two hot lugs (I assume two 120V A/C lines out of phase?) and I'm
guessing that might not sit well with the power supply in this computer.
But then, I'm a rank amateur when it comes to house wiring and A/C and
power supplies and all of that so I thought I'd ask the cctalk collective
whether this can be made to work or if I should simply wait for a
professional to take care of it...
Thanks as always,
Josh
* An AMT DAP 610, if you must ask. It's an array processor from the late
80s, with 64x64 1-bit processors. If the machine doesn't run I'm pretty
much SOL for spare parts, schematics, service manuals, or anything beyond
customer-level documentation (which I've recently scanned, btw, if anyone's
curious...)
11 p.m.
On 2015-Feb-05, at 7:28 PM, Josh Dersch wrote:
I picked up a "large" machine* (for certain
definitions of large) that's currently configured for 220-240V; my house at the moment
lacks 220V receptacles. I was already planning to get an electrician out here to put in
some beefier wiring at some point (I have a couple of machines that draw 15-20A off of
120V that I'd like to be able to run) but I wasn't yet planning on doing 220V
unless I have to.
(It looks like in theory it's possible to reconfigure the supply for 120V but I lack
the docs to do so with any level of confidence...)
I don't know if this machine works, and I'd rather not invest in 220V wiring
quite yet unless it does.
In theory, if you have two 20A 120V circuits installed, you could also have 220V 20A from
the same circuit(s) at the additional expense of just a 220V socket.
However, local codes may have something to say about such an arrangement.
And, let's face it, I'm spoiled and I demand
instant gratification and I'd like to know as soon as possible if this machine is a
basket case or not.
So: since all this stuff is in the basement, I'm just about 15 feet away from the
dryer, which at first glance runs off an outlet that meets my needs. I even have a NEMA
10-30p plug here that I could wire up to the existing power cable for the computer. But
looking into it I have doubts that it's actually that simple; in particular since this
house was built well before 1996 and so the outlet is not grounded; there's a neutral
lug and two hot lugs (I assume two 120V A/C lines out of phase?) and I'm guessing that
might not sit well with the power supply in this computer.
Yes, the two hots are 120VAC to neutral each, 180 degrees out of phase, giving 240 between
the two hots.
Yes, you should be able to use those two hots to power the target machine, as long as the
240 input lines for the target are isolated from ground. Normally this will be the case, I
just mention it in case there is some strange circumstance where one side of the target
input is connected to ground. Measure the R between chassis and the two line inputs, it
should be very high R on both.
Is the existing plug/line input to the the target 3-wire (2 hot + GND) or 4-wire (2 hot +
neutral + GND)?
And have you confirmed that one wire IS GND/chassis? (it could conceivably be 2 hot +
neutral).
But then, I'm a rank amateur when it comes to
house wiring and A/C and power supplies and all of that so I thought I'd ask the
cctalk collective whether this can be made to work or if I should simply wait for a
professional to take care of it...
Thanks as always,
Josh
* An AMT DAP 610, if you must ask. It's an array processor from the late 80s, with
64x64 1-bit processors. If the machine doesn't run I'm pretty much SOL for spare
parts, schematics, service manuals, or anything beyond customer-level documentation (which
I've recently scanned, btw, if anyone's curious...)
11:16 p.m.
On 2/5/2015 8:00 PM, Brent Hilpert wrote:
On 2015-Feb-05, at 7:28 PM, Josh Dersch wrote:
Yes, there's high resistance between both line inputs and chassis
ground, higher than my DVM can measure.
I picked up a "large" machine* (for
certain definitions of large) that's currently configured for 220-240V; my house at
the moment lacks 220V receptacles. I was already planning to get an electrician out here
to put in some beefier wiring at some point (I have a couple of machines that draw 15-20A
off of 120V that I'd like to be able to run) but I wasn't yet planning on doing
220V unless I have to.
(It looks like in theory it's possible to reconfigure the supply for 120V but I lack
the docs to do so with any level of confidence...)
I don't know if this machine works, and I'd rather not invest in 220V wiring
quite yet unless it does.
In theory, if you have two 20A 120V circuits installed,
you could also have 220V 20A from the same circuit(s) at the additional expense of just a
220V socket.
However, local codes may have something to say about such an arrangement.
And, let's face it, I'm spoiled and I
demand instant gratification and I'd like to know as soon as possible if this machine
is a basket case or not.
So: since all this stuff is in the basement, I'm just about 15 feet away from the
dryer, which at first glance runs off an outlet that meets my needs. I even have a NEMA
10-30p plug here that I could wire up to the existing power cable for the computer. But
looking into it I have doubts that it's actually that simple; in particular since this
house was built well before 1996 and so the outlet is not grounded; there's a neutral
lug and two hot lugs (I assume two 120V A/C lines out of phase?) and I'm guessing that
might not sit well with the power supply in this computer.
Yes, the two hots are
120VAC to neutral each, 180 degrees out of phase, giving 240 between the two hots.
Yes, you should be able to use those two hots to power the target machine, as long as the
240 input lines for the target are isolated from ground. Normally this will be the case, I
just mention it in case there is some strange circumstance where one side of the target
input is connected to ground. Measure the R between chassis and the two line inputs, it
should be very high R on both.
Is the existing plug/line input to the the target 3-wire (2 hot + GND) or 4-wire (2 hot +
neutral + GND)?
And have you confirmed that one wire IS GND/chassis? (it could conceivably be 2 hot +
neutral).
The existing plug is a 3-wire affair, white/black for hot and green
ground using a NEMA 6-20P plug. I have confirmed that ground is wired
to the chassis (with the DVM.)
So is it as simple as wiring the white/black wires up to the HOT
terminals on the NEMA connector and leaving the ground disconnected
(from the "netural" pole on the NEMA... or should that be connected as
well)? Anything else I should watch out for?
Thanks,
Josh
But then, I'm a rank amateur when it comes to
house wiring and A/C and power supplies and all of that so I thought I'd ask the
cctalk collective whether this can be made to work or if I should simply wait for a
professional to take care of it...
Thanks as always,
Josh
* An AMT DAP 610, if you must ask. It's an array processor from the late 80s, with
64x64 1-bit processors. If the machine doesn't run I'm pretty much SOL for spare
parts, schematics, service manuals, or anything beyond customer-level documentation (which
I've recently scanned, btw, if anyone's curious...)
11:45 p.m.
On 2015-Feb-05, at 8:16 PM, Josh Dersch wrote:
On 2/5/2015 8:00 PM, Brent Hilpert wrote:
If you are convinced it's wired for 240 then yes, you should be able to wire the hots
as you say.
You MUST somehow GND the chassis however, either:
- confirm the dryer receptacle neutral is adequately tied to ground, or
- if the dryer receptacle is wired with armored/BX cable that may be the ground, or
- waterpipe confirmed as adequate ground, or
- connect to a confirmed ground on a normal 120V outlet, although there is a warning
involved in such a scenario,
if the ground conductor is much smaller than the hot conductor, a fault can blow the
ground conductor open,
at which point you have no ground and a live chassis. In theory the circuit breaker
should open before the ground blows, but that's theory.
Alternatively, if you'd like to examine rewiring the machine for 120, we could look at
that, via photos, etc.
(First question would be what are the target power/VA requirements, to consider whether
it's worthwhile on 120).
On 2015-Feb-05, at 7:28 PM, Josh Dersch wrote:
Yes, there's high resistance between both line inputs and chassis ground, higher than
my DVM can measure.
And, let's face it, I'm spoiled and I
demand instant gratification and I'd like to know as soon as possible if this machine
is a basket case or not.
So: since all this stuff is in the basement, I'm just about 15 feet away from the
dryer, which at first glance runs off an outlet that meets my needs. I even have a NEMA
10-30p plug here that I could wire up to the existing power cable for the computer. But
looking into it I have doubts that it's actually that simple; in particular since this
house was built well before 1996 and so the outlet is not grounded; there's a neutral
lug and two hot lugs (I assume two 120V A/C lines out of phase?) and I'm guessing that
might not sit well with the power supply in this computer.
Yes, the two hots are
120VAC to neutral each, 180 degrees out of phase, giving 240 between the two hots.
Yes, you should be able to use those two hots to power the target machine, as long as the
240 input lines for the target are isolated from ground. Normally this will be the case, I
just mention it in case there is some strange circumstance where one side of the target
input is connected to ground. Measure the R between chassis and the two line inputs, it
should be very high R on both.
Is the existing plug/line input to the the target 3-wire (2 hot + GND) or 4-wire (2 hot +
neutral + GND)?
And have you confirmed that one wire IS GND/chassis? (it could conceivably be 2 hot +
neutral).
The existing plug is a 3-wire affair, white/black for hot and green ground using a NEMA
6-20P plug. I have confirmed that ground is wired to the chassis (with the DVM.)
So is it as simple as wiring the white/black wires up to the HOT terminals on the NEMA
connector and leaving the ground disconnected (from the "netural" pole on the
NEMA... or should that be connected as well)? Anything else I should watch out for?
6 Feb
6 Feb
12:22 a.m.
On 2/5/2015 8:45 PM, Brent Hilpert wrote:
On 2015-Feb-05, at 8:16 PM, Josh Dersch wrote:
OK: Confirmed two things: There's 240V between the two HOT terminals
at the outlet, and the ground appears to be grounded (I get continuity
between the ground on the nearby 120V outlet (which I know is properly
grounded) and the neutral terminal of the 240V outlet.)
So it looks like I should be good to go here. One last question -- does
it matter which hot wire goes to which terminal in this case?
On 2/5/2015 8:00 PM, Brent Hilpert wrote:
If you are convinced it's wired for 240 then yes, you should be able to wire
the hots as you say.
You MUST somehow GND the chassis however, either:
- confirm the dryer receptacle neutral is adequately tied to ground, or
- if the dryer receptacle is wired with armored/BX cable that may be the ground, or
- waterpipe confirmed as adequate ground, or
- connect to a confirmed ground on a normal 120V outlet, although there is a warning
involved in such a scenario,
if the ground conductor is much smaller than the hot conductor, a fault can blow the
ground conductor open,
at which point you have no ground and a live chassis. In theory the circuit breaker
should open before the ground blows, but that's theory. On 2015-Feb-05, at 7:28 PM, Josh Dersch wrote:
Yes, there's high resistance between both line
inputs and chassis ground, higher than my DVM can measure.
And, let's face it, I'm spoiled and I
demand instant gratification and I'd like to know as soon as possible if this machine
is a basket case or not.
So: since all this stuff is in the basement, I'm just about 15 feet away from the
dryer, which at first glance runs off an outlet that meets my needs. I even have a NEMA
10-30p plug here that I could wire up to the existing power cable for the computer. But
looking into it I have doubts that it's actually that simple; in particular since this
house was built well before 1996 and so the outlet is not grounded; there's a neutral
lug and two hot lugs (I assume two 120V A/C lines out of phase?) and I'm guessing that
might not sit well with the power supply in this computer.
Yes, the two hots are
120VAC to neutral each, 180 degrees out of phase, giving 240 between the two hots.
Yes, you should be able to use those two hots to power the target machine, as long as the
240 input lines for the target are isolated from ground. Normally this will be the case, I
just mention it in case there is some strange circumstance where one side of the target
input is connected to ground. Measure the R between chassis and the two line inputs, it
should be very high R on both. Is the existing plug/line input to the the target
3-wire (2 hot + GND) or 4-wire (2 hot + neutral + GND)?
And have you confirmed that one wire IS GND/chassis? (it could conceivably be 2 hot +
neutral).
The existing plug is a 3-wire affair, white/black for hot and green
ground using a NEMA 6-20P plug. I have confirmed that ground is wired to the chassis
(with the DVM.)
So is it as simple as wiring the white/black wires up to the HOT terminals on the NEMA
connector and leaving the ground disconnected (from the "netural" pole on the
NEMA... or should that be connected as well)? Anything else I should watch out for?
Alternatively, if you'd like to examine rewiring the machine for 120, we could look
at that, via photos, etc.
(First question would be what are the target power/VA requirements, to consider whether
it's worthwhile on 120).
I have taken one photo (I probably should have taken more since it's a
PITA to get to, but I wasn't planning on rewiring things at the time).
You can find it at:
http://yahozna.dyndns.org/scratch/dap/supply.jpg
According to the panel on the front of the machine, the power draw is
rated at 120V/10A or 240V/5A. So it should run fine on a normal 120V
outlet. But there's a lot to reconfigure, it looks like, and the fans
are all 240V AC units as well...
- Josh
12:53 a.m.
On 2015-Feb-05, at 9:22 PM, Josh Dersch wrote:
On 2/5/2015 8:45 PM, Brent Hilpert wrote:
Nope.
On 2015-Feb-05, at 8:16 PM, Josh Dersch wrote:
OK: Confirmed two things: There's 240V between the two HOT terminals at the outlet,
and the ground appears to be grounded (I get continuity between the ground on the nearby
120V outlet (which I know is properly grounded) and the neutral terminal of the 240V
outlet.)
So it looks like I should be good to go here. One last question -- does it matter which
hot wire goes to which terminal in this case? On 2/5/2015 8:00 PM, Brent Hilpert wrote:
If you are convinced it's wired for 240 then yes, you should be able to wire
the hots as you say.
You MUST somehow GND the chassis however, either:
- confirm the dryer receptacle neutral is adequately tied to ground, or
- if the dryer receptacle is wired with armored/BX cable that may be the ground, or
- waterpipe confirmed as adequate ground, or
- connect to a confirmed ground on a normal 120V outlet, although there is a warning
involved in such a scenario,
if the ground conductor is much smaller than the hot conductor, a fault can blow the
ground conductor open,
at which point you have no ground and a live chassis. In theory the circuit breaker
should open before the ground blows, but that's theory. On 2015-Feb-05, at 7:28 PM, Josh Dersch wrote:
> And, let's face it, I'm spoiled and I demand instant gratification and
I'd like to know as soon as possible if this machine is a basket case or not.
>
> So: since all this stuff is in the basement, I'm just about 15 feet away from
the dryer, which at first glance runs off an outlet that meets my needs. I even have a
NEMA 10-30p plug here that I could wire up to the existing power cable for the computer.
But looking into it I have doubts that it's actually that simple; in particular since
this house was built well before 1996 and so the outlet is not grounded; there's a
neutral lug and two hot lugs (I assume two 120V A/C lines out of phase?) and I'm
guessing that might not sit well with the power supply in this computer.
Yes, the two hots are 120VAC to neutral each, 180 degrees out of phase, giving 240
between the two hots.
Yes, you should be able to use those two hots to power the target machine, as long as the
240 input lines for the target are isolated from ground. Normally this will be the case, I
just mention it in case there is some strange circumstance where one side of the target
input is connected to ground. Measure the R between chassis and the two line inputs, it
should be very high R on both.
Yes, there's high resistance between both line
inputs and chassis ground, higher than my DVM can measure.
Is the existing plug/line input to the the target
3-wire (2 hot + GND) or 4-wire (2 hot + neutral + GND)?
And have you confirmed that one wire IS GND/chassis? (it could conceivably be 2 hot +
neutral).
The existing plug is a 3-wire affair, white/black for hot and green
ground using a NEMA 6-20P plug. I have confirmed that ground is wired to the chassis
(with the DVM.)
So is it as simple as wiring the white/black wires up to the HOT terminals on the NEMA
connector and leaving the ground disconnected (from the "netural" pole on the
NEMA... or should that be connected as well)? Anything else I should watch out for?
Alternatively, if you'd like to examine rewiring the machine for 120, we could look
at that, via photos, etc.
(First question would be what are the target power/VA requirements, to consider whether
it's worthwhile on 120).
I have taken one photo (I probably should have taken more since it's a PITA
to get to, but I wasn't planning on rewiring things at the time). You can find it
at:
http://yahozna.dyndns.org/scratch/dap/supply.jpg According to the panel on the front of the machine,
the power draw is rated at 120V/10A or 240V/5A. So it should run fine on a normal 120V
outlet. But there's a lot to reconfigure, it looks like, and the fans are all 240V AC
units as well...
Looks like one has to get inside the blue power supply there to reconfigure it. Not clear
whether there are 2 or 3 connections to the PS there, the 2 browns look to be the same
circuit (connected), but can't quite discern whether the blue and grey are separate or
connected.
1:55 a.m.
On 2/5/2015 9:53 PM, Brent Hilpert wrote:
On 2015-Feb-05, at 9:22 PM, Josh Dersch wrote:
Thanks for the help (to you and everyone else who chimed in!) -- I wired
it up and plugged it in and it came to life quite nicely! All
self-tests pass as evidenced by the below photo:
http://yahozna.dyndns.org/scratch/dap/selftest.jpg
Looks like I'll invest in a 240V outlet or two. Can't wait to get it to
do something useful (for some definition of 'useful'); I'm in the
process of getting the software tapes archived (thanks to the help of a
local QIC expert) but once that's done...
Thanks again,
Josh
OK: Confirmed two things: There's 240V between the two HOT terminals at the outlet,
and the ground appears to be grounded (I get continuity between the ground on the nearby
120V outlet (which I know is properly grounded) and the neutral terminal of the 240V
outlet.)
So it looks like I should be good to go here. One last question -- does it matter which
hot wire goes to which terminal in this case?
Nope. 
5:42 a.m.
On Fri, Feb 6, 2015 at 7:55 AM, Josh Dersch <derschjo at gmail.com> wrote:
On 2/5/2015 9:53 PM, Brent Hilpert wrote:
Congratulations - that computer should privide a lot of fun (although
finding something useful for it to do may be a challenge :-) )
On 2015-Feb-05, at 9:22 PM, Josh Dersch wrote:
Thanks for the help (to you and everyone else who chimed in!) -- I wired
it up and plugged it in and it came to life quite nicely! All self-tests
pass as evidenced by the below photo:
http://yahozna.dyndns.org/scratch/dap/selftest.jpg
Looks like I'll invest in a 240V outlet or two. Can't wait to get it to
do something useful (for some definition of 'useful'); I'm in the process
of getting the software tapes archived (thanks to the help of a local QIC
expert) but once that's done...
Thanks again,
Josh
OK: Confirmed two things: There's 240V between the two HOT terminals
at the outlet, and the ground appears to be grounded (I get continuity
between the ground on the nearby 120V outlet (which I know is properly
grounded) and the neutral terminal of the 240V outlet.)
So it looks like I should be good to go here. One last question -- does
it matter which hot wire goes to which terminal in this case?
Nope.
11:09 a.m.
Impressive 220 wiring on this IBM
mainframe. See last photo of sequence.
http://www.ebay.com/itm/Rare-Opportunity-Vintage-IBM-Computer-complete-syst…
On 2/6/2015 5:42 AM, Raymond Wiker wrote:
On Fri, Feb 6, 2015 at 7:55 AM, Josh
Dersch<derschjo at gmail.com> wrote:
On 2/5/2015 9:53 PM, Brent Hilpert wrote:
Congratulations - that computer should privide a lot of fun (although
finding something useful for it to do may be a challenge :-) )
On 2015-Feb-05, at 9:22 PM, Josh Dersch wrote:
Thanks for the help (to you and everyone else who chimed in!) -- I wired
it up and plugged it in and it came to life quite nicely! All self-tests
pass as evidenced by the below photo:
http://yahozna.dyndns.org/scratch/dap/selftest.jpg
Looks like I'll invest in a 240V outlet or two. Can't wait to get it to
do something useful (for some definition of 'useful'); I'm in the process
of getting the software tapes archived (thanks to the help of a local QIC
expert) but once that's done...
Thanks again,
Josh
OK: Confirmed two things: There's 240V
between the two HOT terminals
at the outlet, and the ground appears to be grounded (I get continuity
between the ground on the nearby 120V outlet (which I know is properly
grounded) and the neutral terminal of the 240V outlet.)
So it looks like I should be good to go here. One last question -- does
it matter which hot wire goes to which terminal in this case?
Nope.
5 Feb
5 Feb
11:17 p.m.
On 02/05/2015 08:00 PM, Brent Hilpert wrote:
In theory, if you have two 20A 120V circuits
installed, you could also have 220V 20A from the same circuit(s) at the additional expense
of just a 220V socket.
However, local codes may have something to say about such an arrangement.
Have a peek in the breaker box--you should see the third neutral wire
connected to the common neutral bus, which should also be connected to
the ground bus. At least that's the way it is in my house.
The practice for 240V appliance wiring in the US for many years has been
3-wire, with the third wire used as both a neutral return for 120V
circuits (many cooktops and ovens use this) and also the chassis ground.
Modern code demands that 4 wires be used in that case, with a separate
ground run, but I suspect that the majority of installations for 240V
appliances in the US still use the old 3-wire system.
--Chuck
11:16 p.m.
I picked up a "large" machine* (for certain
definitions of large)
that's currently configured for 220-240V; [...]
[...]
So: since all this stuff is in the basement, I'm just about 15 feet
away from the dryer, [...] since this house was built well before
1996 and so the outlet is not grounded; [...]
That does not necessarily follow; I know of at least one house built in
the late '70s that had proper grounding all through it. (My parents'
place - they and us (then-)kids built it and I learnt about house
wiring from them in the process.)
there's a neutral lug and two hot lugs (I assume
two 120V A/C lines
out of phase?)
Yes; its all but certain that it's two 120V lines 180 degrees out of
phase with one another, giving 240V between the two, both because
that's usual for electric dryers in North America and because that's
usual for residental power in North America. (You don't actually _say_
you're in North America, but that's the only place you're likely to be
for which the scenario you describe makes any sense.)
[...]
But then, I'm a rank amateur when it comes to house wiring and A/C
and power supplies and all of that so I thought I'd ask the cctalk
collective whether this can be made to work [...]
It certainly can be made to work - though finding a decent ground might
be interesting. It borders on certain that the dryer outlet outlet can
feed it what it wants, if either (a) it doesn't care about ground, (b)
the outlet's box actually is grounded, or (c) you can find a suitable
ground elsewhere nearby. You probably could even get away with
connecting the machine's ground to the neutral, though I wouldn't be
comfortable doing that for more than a few minutes of testing - ground
is separate from neutral for good reason.
However, there are a lot of ways it can go wrong, and many of them have
disturbingly high chances of being fatal (eg electrocution hazard) or
severely damaging (eg fire hazard) - there's a lot of power lurking
behind that innocuous-looking dryer outlet. While they are not hard to
avoid for someone used to such things, I would not recommend that "a
rank amateur" try it without someone knowledgeable and experienced on
hand to, at a minimum, give things a look-see before you give it the
juice. This is definitely a place where Pope's famous line about a
little learning being a dangerous thing is accurate - many things in
this hobby you can fiddle with and the worst that'll happen is you fry
the hardware you're playing with, but mains power, in contrast, can
quite literally kill you on the spot or burn your house down.
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11:31 p.m.
Josh,, The neutral and ground are hooked together in the panel. so basically they are
the same.. the dryer plug gives you a couple of good 30 amp 110/120 circuits or
1 good 220/240 volt circuit. The difference is the Neutral is not at ground voltage. it
is loaded some from the load lines, but for what you are doing, make the connection and
give it a try
On Thursday, February 5, 2015 7:28 PM, Josh Dersch <derschjo at gmail.com> wrote:
I picked up a "large" machine* (for certain definitions of large) that's
currently configured for 220-240V; my house at the moment lacks 220V
receptacles. I was already planning to get an electrician out here to
put in some beefier wiring at some point (I have a couple of machines
that draw 15-20A off of 120V that I'd like to be able to run) but I
wasn't yet planning on doing 220V unless I have to.
(It looks like in theory it's possible to reconfigure the supply for
120V but I lack the docs to do so with any level of confidence...)
I don't know if this machine works, and I'd rather not invest in 220V
wiring quite yet unless it does. And, let's face it, I'm spoiled and I
demand instant gratification and I'd like to know as soon as possible if
this machine is a basket case or not.
So: since all this stuff is in the basement, I'm just about 15 feet
away from the dryer, which at first glance runs off an outlet that meets
my needs. I even have a NEMA 10-30p plug here that I could wire up to
the existing power cable for the computer. But looking into it I have
doubts that it's actually that simple; in particular since this house
was built well before 1996 and so the outlet is not grounded; there's a
neutral lug and two hot lugs (I assume two 120V A/C lines out of phase?)
and I'm guessing that might not sit well with the power supply in this
computer.
But then, I'm a rank amateur when it comes to house wiring and A/C and
power supplies and all of that so I thought I'd ask the cctalk
collective whether this can be made to work or if I should simply wait
for a professional to take care of it...
Thanks as always,
Josh
* An AMT DAP 610, if you must ask. It's an array processor from the
late 80s, with 64x64 1-bit processors. If the machine doesn't run I'm
pretty much SOL for spare parts, schematics, service manuals, or
anything beyond customer-level documentation (which I've recently
scanned, btw, if anyone's curious...)
11:41 p.m.
The only annoying thing about this is that if you get between that little
bit of "loaded some from the load lines" that you've shorted to the chassis
and something truly grounded (i.e. by touching the computer and a pipe or
the damp floor with bare feet, etc.), you get to experience the power
differential running through your body. This has always been merely
annoying to be. I don't know if it can kill.
On Thu, Feb 5, 2015 at 11:31 PM, Jerry Wright <g-wright at att.net> wrote:
Josh,, The neutral and ground are hooked together
in the panel. so
basically they are the same.. the dryer plug gives you a couple of good
30 amp 110/120 circuits or
1 good 220/240 volt circuit. The difference is the Neutral is not at
ground voltage. it is loaded some from the load lines, but for what you
are doing, make the connection and give it a try
On Thursday, February 5, 2015 7:28 PM, Josh Dersch <derschjo at gmail.com>
wrote:
I picked up a "large" machine* (for certain definitions of large) that's
currently configured for 220-240V; my house at the moment lacks 220V
receptacles. I was already planning to get an electrician out here to
put in some beefier wiring at some point (I have a couple of machines
that draw 15-20A off of 120V that I'd like to be able to run) but I
wasn't yet planning on doing 220V unless I have to.
(It looks like in theory it's possible to reconfigure the supply for
120V but I lack the docs to do so with any level of confidence...)
I don't know if this machine works, and I'd rather not invest in 220V
wiring quite yet unless it does. And, let's face it, I'm spoiled and I
demand instant gratification and I'd like to know as soon as possible if
this machine is a basket case or not.
So: since all this stuff is in the basement, I'm just about 15 feet
away from the dryer, which at first glance runs off an outlet that meets
my needs. I even have a NEMA 10-30p plug here that I could wire up to
the existing power cable for the computer. But looking into it I have
doubts that it's actually that simple; in particular since this house
was built well before 1996 and so the outlet is not grounded; there's a
neutral lug and two hot lugs (I assume two 120V A/C lines out of phase?)
and I'm guessing that might not sit well with the power supply in this
computer.
But then, I'm a rank amateur when it comes to house wiring and A/C and
power supplies and all of that so I thought I'd ask the cctalk
collective whether this can be made to work or if I should simply wait
for a professional to take care of it...
Thanks as always,
Josh
* An AMT DAP 610, if you must ask. It's an array processor from the
late 80s, with 64x64 1-bit processors. If the machine doesn't run I'm
pretty much SOL for spare parts, schematics, service manuals, or
anything beyond customer-level documentation (which I've recently
scanned, btw, if anyone's curious...)
11:54 p.m.
In the scenario being discussed, there should be no current flowing in the dryer neutral
wire, so the only place there should be a voltage drop would be around the
neutral-bus-bar/ground-link in the panel, which should be negligible - unless the dryer is
linked off a sub-panel where there would an opportunity for other loads on the sub-panel
to produce a voltage drop on the neutral back to the main panel.
On 2015-Feb-05, at 8:31 PM, Jerry Wright wrote:
Josh,, The neutral and ground are hooked together
in the panel. so basically they are the same.. the dryer plug gives you a couple of
good 30 amp 110/120 circuits or
1 good 220/240 volt circuit. The difference is the Neutral is not at ground voltage. it
is loaded some from the load lines, but for what you are doing, make the connection and
give it a try
On Thursday, February 5, 2015 7:28 PM, Josh Dersch <derschjo at gmail.com> wrote:
I picked up a "large" machine* (for certain definitions of large) that's
currently configured for 220-240V; my house at the moment lacks 220V
receptacles. I was already planning to get an electrician out here to
put in some beefier wiring at some point (I have a couple of machines
that draw 15-20A off of 120V that I'd like to be able to run) but I
wasn't yet planning on doing 220V unless I have to.
(It looks like in theory it's possible to reconfigure the supply for
120V but I lack the docs to do so with any level of confidence...)
I don't know if this machine works, and I'd rather not invest in 220V
wiring quite yet unless it does. And, let's face it, I'm spoiled and I
demand instant gratification and I'd like to know as soon as possible if
this machine is a basket case or not.
So: since all this stuff is in the basement, I'm just about 15 feet
away from the dryer, which at first glance runs off an outlet that meets
my needs. I even have a NEMA 10-30p plug here that I could wire up to
the existing power cable for the computer. But looking into it I have
doubts that it's actually that simple; in particular since this house
was built well before 1996 and so the outlet is not grounded; there's a
neutral lug and two hot lugs (I assume two 120V A/C lines out of phase?)
and I'm guessing that might not sit well with the power supply in this
computer.
But then, I'm a rank amateur when it comes to house wiring and A/C and
power supplies and all of that so I thought I'd ask the cctalk
collective whether this can be made to work or if I should simply wait
for a professional to take care of it...
Thanks as always,
Josh
* An AMT DAP 610, if you must ask. It's an array processor from the
late 80s, with 64x64 1-bit processors. If the machine doesn't run I'm
pretty much SOL for spare parts, schematics, service manuals, or
anything beyond customer-level documentation (which I've recently
scanned, btw, if anyone's curious...)
6 Feb
6 Feb
3:23 p.m.
I picked up a "large" machine* (for certain definitions of large) that's
It's not that large. Or at least mine isn't, Deskside, really.
I don't know if this machine works, and I'd
rather not invest in 220V
wiring quite yet unless it does. And, let's face it, I'm spoiled and I
demand instant gratification and I'd like to know as soon as possible if
this machine is a basket case or not.
FWIW, mine currently has PSU problems (which is why I was given it). The
choppers are dead short all ways round. But it is a fairly conventional SMPSU
in there, albeit a large one (750W? 1kW?). You may be able to reconfigure it
for 115V mains, but watch out for the fans
So: since all this stuff is in the basement, I'm
just about 15 feet
away from the dryer, which at first glance runs off an outlet that meets
my needs. I even have a NEMA 10-30p plug here that I could wire up to
the existing power cable for the computer. But looking into it I have
doubts that it's actually that simple; in particular since this house
was built well before 1996 and so the outlet is not grounded; there's a
neutral lug and two hot lugs (I assume two 120V A/C lines out of phase?)
and I'm guessing that might not sit well with the power supply in this
computer.
This will not meet any kind of electrical code, but it should be OK for testing...
The DAP doesb't care that the 230V is centre-tapped to ground (in fact that is
expected in the States). The ground to the case is a safety ground only.
So I would first check you get 230V (or so) between the 2 'hot' pins of the dryer
socket. If so, then wire up a kludge cable that connects those to the power pins
of the DAP and the ground pin to a good local ground (if necessary the ground
pin of a normal 115V socket outlet). This would allow you to power up the machine.
* An AMT DAP 610, if you must ask. It's an array
processor from the
late 80s, with 64x64 1-bit processors. If the machine doesn't run I'm
Is it as many as that? I thought mine was 32*32, but maybe you have a bigger
machine. Mine says DAP610 on it.
I only have user manuals, but I have thought about trying to figure out the hardware
at some point. Maybe I will manage it.
pretty much SOL for spare parts, schematics, service
manuals, or
anything beyond customer-level documentation (which I've recently
scanned, btw, if anyone's curious...)
-tony
4:28 p.m.
On Fri, Feb 6, 2015 at 12:23 PM, tony duell <ard at p850ug1.demon.co.uk> wrote:
The one I have is (approximately) 5'x2'x4' and weighs about 600lbs. I
think the 500-series was about half as tall, from what I've been able to
find. It's not as big as a full-size rack, but it's not deskside either.
(It does have wheels, fortunately :)).
I was amused to discover a connection to the PERQ when researching this
beast (the 'PERQ-DAP' which used a PERQ as the front end) which I'm
guessing you're already aware of :).
Yeah, there are two supplies in mine, a big supply for the +5 and a smaller
one for other voltages, I believe. The fans are all 240V units, so they'd
likely need to be changed out. I'm fine at this point just getting a real,
up-to-code 240V outlet installed at some point in the not-too-distant
future to run this (and other future machines that are similarly
power-hungry.)
Yep, did this last night and it worked; everything powered up nicely,
fortunately.
I picked up a "large" machine* (for certain definitions of large) that's
It's not that large. Or at least mine isn't, Deskside, really.
I don't know if this machine works, and
I'd rather not invest in 220V
wiring quite yet unless it does. And, let's face it, I'm spoiled and I
demand instant gratification and I'd like to know as soon as possible if
this machine is a basket case or not.
FWIW, mine currently has PSU problems (which is why I was given it). The
choppers are dead short all ways round. But it is a fairly conventional
SMPSU
in there, albeit a large one (750W? 1kW?). You may be able to reconfigure
it
for 115V mains, but watch out for the fans
So: since all this stuff is in the basement,
I'm just about 15 feet
away from the dryer, which at first glance runs off an outlet that meets
my needs. I even have a NEMA 10-30p plug here that I could wire up to
the existing power cable for the computer. But looking into it I have
doubts that it's actually that simple; in particular since this house
was built well before 1996 and so the outlet is not grounded; there's a
neutral lug and two hot lugs (I assume two 120V A/C lines out of phase?)
and I'm guessing that might not sit well with the power supply in this
computer.
This will not meet any kind of electrical code, but it should be OK for
testing...
The DAP doesb't care that the 230V is centre-tapped to ground (in fact
that is
expected in the States). The ground to the case is a safety ground only.
So I would first check you get 230V (or so) between the 2 'hot' pins of
the dryer
socket. If so, then wire up a kludge cable that connects those to the
power pins
of the DAP and the ground pin to a good local ground (if necessary the
ground
pin of a normal 115V socket outlet). This would allow you to power up the
machine.
* An AMT DAP 610, if you must ask. It's an
array processor from the
late 80s, with 64x64 1-bit processors. If the machine doesn't run I'm
Is it as many as that? I thought mine was 32*32, but maybe you have a
bigger
machine. Mine says DAP610 on it.
From the docs I have, the 510 is 32x32, and the 610 is
64x64. My machine
has a midplane with 8 Array boards per side, and 4 large ceramic
chips per
Array board (which I assume contain 64 processors each...)
I only have user manuals, but I have thought about trying to figure out
the hardware
at some point. Maybe I will manage it.
I got manuals and tapes with mine; I scanned the docs and them off to Al
(and they appear to be on bitsavers now -- thanks Al!). The tapes are
being worked on...
- Josh
pretty much SOL for spare parts, schematics,
service manuals, or
anything beyond customer-level documentation (which I've recently
scanned, btw, if anyone's curious...)
-tony
5:15 p.m.
On Fri, Feb 6, 2015 at 1:28 PM, Josh Dersch <derschjo at gmail.com> wrote:
The one I have is (approximately) 5'x2'x4' and weighs about 600lbs. I
think the 500-series was about half as tall, from what I've been able to
find. It's not as big as a full-size rack, but it's not deskside either.
(It does have wheels, fortunately :)).
How many people did it take to get that into your basement?
5:19 p.m.
On Fri, Feb 6, 2015 at 2:15 PM, Glen Slick <glen.slick at gmail.com> wrote:
On Fri, Feb 6, 2015 at 1:28 PM, Josh Dersch
<derschjo at gmail.com> wrote:
Only three! Luckily heavy items can be wheeled on a hand-cart around to
the back of the house, where there's direct access to the basement; no
tricky stairs to deal with. In this case, taking off all the extraneous
paneling on the front/rear/sides and top cut quite a bit of weight and made
it a lot easier to hold onto...
- Josh
The one I have is (approximately) 5'x2'x4' and weighs about 600lbs. I
think the 500-series was about half as tall, from what I've been able to
find. It's not as big as a full-size rack, but it's not deskside either.
(It does have wheels, fortunately :)).
How many people did it take to get that into your basement?
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18 comments
10 participants
participants (10)
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ard＠p850ug1.demon.co.uk -
cclist＠sydex.com -
derschjo＠gmail.com -
g-wright＠att.net -
glen.slick＠gmail.com -
hilpert＠cs.ubc.ca -
jacob.ritorto＠gmail.com -
js＠cimmeri.com -
mouse＠Rodents-Montreal.ORG -
rwiker＠gmail.com