25 Jul
2000
25 Jul
'00
12:21 p.m.
My PDP 8/e has its power cable cut off. The wires are color coded White,
Black, Green. This is for a Dec H724 power supply.
Does anyone have any schematics or doc that would tell me how to connect
those 3 wires to a power plug? Its about time I powered this thing up
to see if the capacitors are working. I dont have an electronics
test bench, so i'll just have to pull the boards out and turn it on,
and hope for the best.
-Lawrence LeMay
25 Jul
25 Jul
1:03 p.m.
My PDP 8/e has its power cable cut off. The wires are
color coded White,
Black, Green. This is for a Dec H724 power supply.
Does anyone have any schematics or doc that would tell me how to connect
those 3 wires to a power plug? Its about time I powered this thing up
to see if the capacitors are working. I dont have an electronics
test bench, so i'll just have to pull the boards out and turn it on,
and hope for the best.
In fact, I borrowed a fluke multimeter, and there is only about 0.2 Ohm
resistance between the green wire and the case, so that must be the
case ground wire. Do the other two matter much on a 3 prong connector?
resistance between teh green wire and the case, so that must be the
Polarized AC was always confusing to me...
-Lawrence LeMay
1:59 p.m.
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2:31 p.m.
In fact, I borrowed a fluke multimeter, and there is
only about 0.2 Ohm
resistance between the green wire and the case, so that must be the
case ground wire. Do the other two matter much on a 3 prong connector?
Yes, they matter in some cases. Often more in terms of safety than
functionality.
A month or two ago I happened to plug a piece of equipment in which some
dolt (technical term) had connected neutral to ground into an extension
cord that some other dolt had wired with a hot-neutral swap. The results
were nothing short of spectacular on a high current laboratory circuit.
If I knew the identity of either dolt, I think I would teach them the
difference between hot, neutral and ground in a way they wouldn't soon forget.
Eric
2:47 p.m.
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1:03 p.m.
White is "hot", black is "neutral" and green is ground. Most of the
screw
on plugs have a legend on them or on the package. Remember they are
designed for people who have no training to install.
--Chuck
At 04:21 PM 7/25/00 -0500, you wrote:
My PDP 8/e has its power cable cut off. The wires are
color coded White,
Black, Green. This is for a Dec H724 power supply.
Does anyone have any schematics or doc that would tell me how to connect
those 3 wires to a power plug? Its about time I powered this thing up
to see if the capacitors are working. I dont have an electronics
test bench, so i'll just have to pull the boards out and turn it on,
and hope for the best.
-Lawrence LeMay
3 p.m.
I disagree!
Black is hot, white is neutral. The Black (hot) wire should connect to the slightly
smaller
prong of the power plug. It will work either way, but it will only be compliant with
electrical code if you connect it correctly.
Mark Champion
mark.champion(a)am.sony.com
----- Original Message -----
From: "Chuck McManis" <cmcmanis(a)mcmanis.com>
To: <classiccmp(a)classiccmp.org>
Sent: Tuesday, July 25, 2000 3:03 PM
Subject: Re: PDP 8/e power wires
White is "hot", black is "neutral"
and green is ground. Most of the screw
on plugs have a legend on them or on the package. Remember they are
designed for people who have no training to install.
--Chuck
At 04:21 PM 7/25/00 -0500, you wrote:
>My PDP 8/e has its power cable cut off. The wires are color coded White,
>Black, Green. This is for a Dec H724 power supply.
>
>Does anyone have any schematics or doc that would tell me how to connect
>those 3 wires to a power plug? Its about time I powered this thing up
>to see if the capacitors are working. I dont have an electronics
>test bench, so i'll just have to pull the boards out and turn it on,
>and hope for the best.
>
>-Lawrence LeMay
3 p.m.
White is "hot", black is "neutral"
and green is ground. Most of the screw
on plugs have a legend on them or on the package. Remember they are
designed for people who have no training to install.
I always thought that the "usual" color code for electrical wiring was
BLACK is HOT, WHITE is NEUTRAL, and green is ground. Am I remembering it
wrong? or is the PDP 8/e backwards from everything else?
'Course, if you soak them in WD-40 long enough, it might not matter.
--
Grumpy Ol' Fred cisin(a)xenosoft.com
3:04 p.m.
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5:31 p.m.
----- Original Message -----
From: "Tony Duell" <ard(a)p850ug1.demon.co.uk>
To: <classiccmp(a)classiccmp.org>
Sent: Wednesday, July 26, 2000 9:34 AM
Subject: Re: PDP 8/e power wires
>
> > White is "hot", black is "neutral" and green is ground.
Most of
the screw
> > on plugs have a legend on them or on the
package. Remember they
are
> > designed for people who have no training to
install.
>
> I always thought that the "usual" color code for electrical wiring
was
> BLACK is HOT, WHITE is NEUTRAL, and green is
ground. Am I
remembering it
That's how I've always wired US stuff. It's also how all such
equipment
_including_ DEC machines seems to have been wired at
the factory, and
how
the service manuals/prints show it.
Which standard is it just as a matter of interest? Sounds a bit silly
to me
Aust standards (current) are Active - Brown Neutral - Blue Ground -
Green with Yellow Tracer
The old spec (pre 1975? - somewhen around there) was Active - Red
Neutral - Black Ground - Green,
which I always considered sensible.
Cheers
Geoff Roberts
Computer Systems Manager
Saint Mark's College
Port Pirie,
South Australia
geoffrob(a)stmarks.pp.catholic.edu.au
netcafe(a)tell.net.au
ICQ: 1970476
wrong? or is the PDP 8/e backwards from
everything else?
No, DEC used the standard colour codes here.
26 Jul
26 Jul
9:01 a.m.
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25 Jul
25 Jul
4:01 p.m.
At 15:03 25-07-2000 -0700, Chuck McManis wrote:
White is "hot", black is "neutral"
and green is ground. Most of the screw
on plugs have a legend on them or on the package. Remember they are
designed for people who have no training to install.
NononononoNO! Just the opposite!
White is neutral, black hot, and green ground. Trust me, I know this,
because I got the difference thoroughly drilled into my brain when I
replaced our house's breaker panel last summer.
Reverse black and white at your peril!
-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-
Bruce Lane, Owner and head honcho, Blue Feather Technologies
http://www.bluefeathertech.com // E-mail: kyrrin(a)bluefeathertech.com
Amateur Radio: WD6EOS since Dec. '77
"Our science can only describe an object, event, or living thing in our
own human terms. It cannot, in any way, define any of them..."
1:52 p.m.
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26 Jul
26 Jul
2:33 p.m.
The power supply in a PDP8/e will run with no load (this is from
experience). To test if off-load you can pull the 2 plugs that go to the
backplanes, and the smaller 3-pin plug for the feed to the line time
clock (if it's used at all). Power up. And then check the voltage between
the backplane connector pin that went to the black wire (ground) and the
one that went to the red wire (+5V). If this is not +5V, then you need to
sort out the PSU. My printset is here...
-tony
Well, I attached a new 110V 15Amp power plug, so I plan to turn the
PDP 8/e on sometime thursday for about 2 hours or so (assuming the
power supply works) in order to warm up the capacitors.
My plan was to have ALL the boards pulled from the backplane, leaving just
the front panel plugged in. Unless someone gives me a good reason not
to do this. Should I plug in the M8320 Buss Loads board?
I'm assuming that if this beast powers up, that I can probably deposit
the switch register into the memory address register, even without the
core memory or any of the "CPU" cards installed. The extended addr switch
doesnt appear to be working, and at least 2 of the paddles are broken,
but i'm still hoping for the best at this point. Hmm, on second thought,
arent all the registers contained on M8310, so I wont be able to do
anything until I power up with a basic set of boards installed?
Assuming it powers up, do you think 2 hours is long enough for the initial
"burn in"?
-Lawrence LeMay
2:43 p.m.
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25 Jul
25 Jul
3:44 p.m.
Hi,
The White wire goes to the silver terminal on the plug.
The Black wire goes to the gold terminal on the plug.
The Green wire goes to the green terminal on the plug.
If your plug doesn't have silver, gold and green, buy a new
plug.
Also, make very sure about the expected voltage. I had purchased
a 220V twist lock plug, and completly installed it before thinking
to check if the rack was 110V or 220V. Fortunately, I discovered it
was a 110V 30A plug I needed before plugging it in (and killing
three harddrives, controller, and an STC 9-track tape drive).
clint
On Tue, 25 Jul 2000, Lawrence LeMay wrote:
My PDP 8/e has its power cable cut off. The wires are
color coded White,
Black, Green. This is for a Dec H724 power supply.
Does anyone have any schematics or doc that would tell me how to connect
those 3 wires to a power plug? Its about time I powered this thing up
to see if the capacitors are working. I dont have an electronics
test bench, so i'll just have to pull the boards out and turn it on,
and hope for the best.
-Lawrence LeMay
8763
days inactive
8764
days old
15 comments
9 participants
participants (9)
-
ard＠p850ug1.demon.co.uk -
cisin＠xenosoft.com -
cmcmanis＠mcmanis.com -
geoffrob＠stmarks.pp.catholic.edu.au -
korpela＠ellie.ssl.berkeley.edu -
kyrrin＠bluefeathertech.com -
lemay＠cs.umn.edu -
mark.champion＠am.sony.com -
vaxman＠uswest.net