16 Jan
1998
16 Jan
'98
1:11 p.m.
Having an IBM mainframe would be great provided you have a direct
connect to the nearest power station! Here's several messages from
knowledgeable folks that posted to alt.folklore.computers awhile back:
[Message 1 of 4 in thread 148 of 176] alt.folklore.computers
Re: IBM Mainframes: Power & Coolant Requirements
From: Alan Greenberg <ALAN(a)VM1.McGill.CA>
Date: Wed, 23 Aug 95 20:33:11 EDT (Page 1 of 2)
In article <BNIDrJa.jrbrady(a)delphi.com>
Jason Brady <jrbrady(a)delphi.com> writes:
Does anyone have any insights as to the power requirements for the
beasts? How about the liquid coolant (I think one of the many system
components was the PDU "power/coolant distribution unit"?)
We just
replaced a two processor 3090 with a new CMOS-based system.
The new systems was cost-justified partly on the energy savings.
The processor complex ate up about 55 KVA, mostly in 415 Hz power
(which is what the motor-generator created from 60 Hz - just as
with airborne equipment, the higher frequency makes for smaller
DC power supplies). Onto that, you need to add the cost of
removing the heat - perhaps another 25-50% for a total power
consumption of about 60-70 KVA. A complex with more processors
would of course take more power.
I should point out that this was a 9 year old machine....
We replaced it with a new box that draw less than 1,500 watts!
Alan Greenberg
Re: IBM Mainframes: Power & Coolant Requirements
From: Joe Morris <jcmorris(a)mwunix.mitre.org>
Date: 24 Aug 1995 14:42:30 GMT (Page 1 of 2)
Jason Brady <jrbrady(a)delphi.com> writes:
I never got involved with the facilities support side
of the place, but
remember one day when an emergency shutdown was attributed to a "motor-
generator failure."
A lot of the big systems used MG sets, both as frequency
translators (some
circuits were designed for 400 Hz supply) and as an isolation mechanism
to prevent garbage on the power feed from getting into the computer. The
rotating mass of the MG provided excellent ride-through for short outages
of the commercial power.
At a PPOE in the mid-1970s we had an IBM 370/148 (with MG), an IBM 360/65
(no MG) and a DEC DECsystem KL10 (no MG). We also had a Dranitz power line
monitor tied to the power mains; based on its output we could show how
well the systems handled dropouts in the power.
The DECsystem 10 never survived more than about 3 or 4 cycles outage; the
360/65 died at about 16 cycles, and the 148 could tolerate almost a
full second. (We got lots of opportunities to collect data points ...
thanks, TVA.)
Of course, the peripherals on the 148 would usually die on an outage of
one second, but the CPU itself would survive without taking a power check.
(The shop didn't have the funds and/or will to buy a UPS, even though I
managed to include a room for one in the building when it was designed.)
The problem with the DEC box didn't surprise me at all. There were a
lot of nice features in the design, but the impression I got was that
DEC designed the power circuits on a day after the engineers had spent
the previous night in a bar. At one time I found that the box was
dumping almost 8A of current down the *ground* line, yet the DEC
CE insisted that the box was installed and working correctly. It
also was dumping over 20A down the neutral line on a 3-phase circuit;
not the safety issue of ground current, but still indicative of poor
design.
Joe Morris / MITRE
[Message 3 of 4 in thread 148 of 176] alt.folklore.computers
Re: IBM Mainframes: Power & Coolant Requirements
From: Joe Morris <jcmorris(a)mwunix.mitre.org>
Date: 24 Aug 1995 15:04:21 GMT (Page 1 of 2)
Responding to: <41e5j3$id(a)news.iadfw.net>
mcw(a)gateway.airmail.net (Mike Wommack) writes:
I used to work as an Electrician at an IBM site a few
years back. I know
the 3380(?) DASD strings took 220v at 100A. The plugs were huge. I also
recall what looked like 3/4" water lines used to cool the main processor.
(Which was either a 3090 or ES9000.)
If it was a US site, the 3380 box probably was
being fed with 208VAC,
3-phase power at no more than 60A; the box is spec'ed at requiring
no more than 8.2 KVA. In the case of the 3380 the power connector
is an R&S 7328 plug, which is rated at only 60A.
(You could get the box wired for other voltages, so a 220 VAC feed
is possible but if that was the voltage the current draw would have
been even less than at 208.)
The size of the connectors in the power lines is often mandated by NEC
(National Electric Code) and/or local code requirements, which for
underfloor installation often require watertight connections (and thus
increase the size of the connector).
Joe Morris / MITRE
18 Jan
18 Jan
10:19 a.m.
So, trying to scare me, ehh?
Having an IBM mainframe would be great provided you
have a direct
connect to the nearest power station! Here's several messages from
knowledgeable folks that posted to alt.folklore.computers awhile back:
<lots of useful info snipped>
OK, running a big mini or a mainframe class machine is not for everyone.
However, running a processor plus a single disk and perhaps a tape may not
be all that bad. Water cooled machines, however, would be too much to
handle.
For those that only want to plug things into the wall, turn back now!
A typical mainframe machine from the past is going to want 3-phase power.
While most people do not have access to it, it can be produced or the
equipment modified to run off single phase. 3-phase can be made from a
phase shift network, a motor-generator, or a Scott connected transformer
fed by a second phase. Most of these solutions are a bit costly, not very
efficient, and probably a general pain in the butt. The better solution is
to look at the power supplies in the computer. Often the three phase is
only split up amongst the supplies, and maybe for some fans (or in the
case of some IBM tape drives _fractional_ horsepower motors to move the
glass doors up and down - expensive, but clever). A simple way to go would
be to rewire the supplies (in a reversable fashion) to work off one phase,
and maybe get a small convertor for the fans - no big deal. PDP-10s can be
run this way - its been done. Most others probably can as well. If,
however, the mains go into a 3 phase transformer, some thinking is
required. Many 3-phase transformer _can_ be run on a single phase nicely,
but the correct windings must be left open or shorted (if I can dig out a
past issue of *Electric Radio* magazine, I can come up with specifics.
Some hams need to do this trick to get vintage broadcast transmitters
operating from thier shacks.).
Some big old IBM systems want to have 400 Hz power. It is used so the
power supplies can be made smaller, especially in the filtering circuits.
This is probably more of a problem that needing 3-phase (a double whammy
if 400 Hz 3-phase power is needed!), because 400 Hz supplies are
EXPENSIVE, often taking the shape of big motor-generators.
Anyway, how much power do these computers require? Lots, but perhaps not
as much as one might think. A fully decked out 3081 CPU only needs about 7
kVA. I am sure something like a smaller S/360 or 370 would be less - my
guess is at 4 to 5 kVA. As long as you do not run the thing all day, it
will not be that expensive! For example, maybe running a small mainframe,
plus a disk and tape, for a night of hacking might cost $10 in
electricity. Running something smaller like a big PDP-11 system might cost
a couple of bucks - large deal. Compared to some hobbies dealing with older
technology (airplanes, cars, trains, boats, etc.) - that is not much.
One last point I would like to make is that before you go and try out your
newly aquired Big Blue Box, check out the circuits that you will be using.
The startup currents for some of the things can be nasty, and a jammed
circuit breaker is certainly _not_ a good thing.
William Donzelli
william(a)ans.net
1:11 p.m.
William Donzelli wrote:
Some big old IBM systems want to have 400 Hz power. It
is used so the
power supplies can be made smaller, especially in the filtering circuits.
This is probably more of a problem that needing 3-phase (a double whammy
if 400 Hz 3-phase power is needed!), because 400 Hz supplies are
EXPENSIVE, often taking the shape of big motor-generators.
So go to your nearest airport and steal an APU. 400hz 3-phase is
standard aircraft electrics (because motors and such can be made
smaller). It's what I dealt with in the USAF -- didn't know it
was popular on the ground once away from the maintenance shops
around the flightline. (Oh, that APU will burn kerosene very
happily -- in fact, if you try gasoline, your neighbors will
object loudly when it blows up and burns down the neighborhood.
--
Ward Griffiths
Dylan: How many years must some people exist,
before they're allowed to be free?
WDG3rd: If they "must" exist until they're "allowed",
they'll never be free.
4:03 p.m.
On Sun, 18 Jan 1998, William Donzelli wrote:
So, trying to scare me, ehh?
One scheme that I have seen used to power a 3-phase motor (on a lathe or
such) is to connect a 3-phase motor of comparable rating or higher to the
single-phase mains and also connect all three phases to the motor to be
powered. The motor connected to mains is powered up - it may require a
twist to get it spinning - and when up to a steady speed, the lathe (or
whatever) motor may be powered up. I'm sure that there are some
inefficiencies, but I have seen it work.
- don
Having an IBM mainframe would be great provided
you have a direct
connect to the nearest power station! Here's several messages from
knowledgeable folks that posted to alt.folklore.computers awhile back:
<lots of useful info snipped>
OK, running a big mini or a mainframe class machine is not for everyone.
However, running a processor plus a single disk and perhaps a tape may not
be all that bad. Water cooled machines, however, would be too much to
handle.
For those that only want to plug things into the wall, turn back now!
A typical mainframe machine from the past is going to want 3-phase power.
While most people do not have access to it, it can be produced or the
equipment modified to run off single phase. 3-phase can be made from a
phase shift network, a motor-generator, or a Scott connected transformer
fed by a second phase. Most of these solutions are a bit costly, not very
efficient, and probably a general pain in the butt. The better solution is
to look at the power supplies in the computer. Often the three phase is
only split up amongst the supplies, and maybe for some fans (or in the
case of some IBM tape drives _fractional_ horsepower motors to move the
glass doors up and down - expensive, but clever). A simple way to go would
be to rewire the supplies (in a reversable fashion) to work off one phase,
and maybe get a small convertor for the fans - no big deal. PDP-10s can be
run this way - its been done. Most others probably can as well. If,
however, the mains go into a 3 phase transformer, some thinking is
required. Many 3-phase transformer _can_ be run on a single phase nicely,
but the correct windings must be left open or shorted (if I can dig out a
past issue of *Electric Radio* magazine, I can come up with specifics.
Some hams need to do this trick to get vintage broadcast transmitters
operating from thier shacks.). Some big old IBM systems want to have 400 Hz power. It
is used so the
power supplies can be made smaller, especially in the filtering circuits.
This is probably more of a problem that needing 3-phase (a double whammy
if 400 Hz 3-phase power is needed!), because 400 Hz supplies are
EXPENSIVE, often taking the shape of big motor-generators.
Anyway, how much power do these computers require? Lots, but perhaps not
as much as one might think. A fully decked out 3081 CPU only needs about 7
kVA. I am sure something like a smaller S/360 or 370 would be less - my
guess is at 4 to 5 kVA. As long as you do not run the thing all day, it
will not be that expensive! For example, maybe running a small mainframe,
plus a disk and tape, for a night of hacking might cost $10 in
electricity. Running something smaller like a big PDP-11 system might cost
a couple of bucks - large deal. Compared to some hobbies dealing with older
technology (airplanes, cars, trains, boats, etc.) - that is not much.
One last point I would like to make is that before you go and try out your
newly aquired Big Blue Box, check out the circuits that you will be using.
The startup currents for some of the things can be nasty, and a jammed
circuit breaker is certainly _not_ a good thing.
William Donzelli
william(a)ans.net
donm(a)cts.com
*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*
Don Maslin - Keeper of the Dina-SIG CP/M System Disk Archives
Chairman, Dina-SIG of the San Diego Computer Society
Clinging tenaciously to the trailing edge of technology.
Sysop - Elephant's Graveyard (CP/M) - 619-454-8412
*--*--*--*--*--*--*--*--*--*--*--*--*--*--*--*--*--*--*--*--*--*--*--*--*
see old system support at http://www.psyber.com/~tcj
4:48 p.m.
One scheme that I have seen used to power a 3-phase
motor (on a lathe or
such) is to connect a 3-phase motor of comparable rating or higher to the
single-phase mains and also connect all three phases to the motor to be
powered. The motor connected to mains is powered up - it may require a
twist to get it spinning - and when up to a steady speed, the lathe (or
whatever) motor may be powered up. I'm sure that there are some
inefficiencies, but I have seen it work.
Yes, it works, but is quite inefficient. I would venture to say that using
a real motor-generator would be better, if properly maintained.
Motor-generators are not as bad as most people think - a good one is
fairly efficient, provides isolation and regulation, and can take a lot of
electrical abuse. They are just bears to move (done it - not fun).
William Donzelli
william(a)ans.net
19 Jan
19 Jan
5:29 a.m.
On Mon, 19 Jan 1998, William Donzelli wrote:
Can't quarrel with that, but the price difference between an old 3-phase
induction motor and an MG set can be rather impressive!
- don
One scheme
that I have seen used to power a 3-phase motor (on a lathe or
such) is to connect a 3-phase motor of comparable rating or higher to the
single-phase mains and also connect all three phases to the motor to be
powered. The motor connected to mains is powered up - it may require a
twist to get it spinning - and when up to a steady speed, the lathe (or
whatever) motor may be powered up. I'm sure that there are some
inefficiencies, but I have seen it work.
Yes, it works, but is quite inefficient. I would venture to say that using
a real motor-generator would be better, if properly maintained. Motor-generators are not as bad as most people think -
a good one is
fairly efficient, provides isolation and regulation, and can take a lot of
electrical abuse. They are just bears to move (done it - not fun).
William Donzelli
william(a)ans.net
donm(a)cts.com
*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*
Don Maslin - Keeper of the Dina-SIG CP/M System Disk Archives
Chairman, Dina-SIG of the San Diego Computer Society
Clinging tenaciously to the trailing edge of technology.
Sysop - Elephant's Graveyard (CP/M) - 619-454-8412
*--*--*--*--*--*--*--*--*--*--*--*--*--*--*--*--*--*--*--*--*--*--*--*--*
see old system support at http://www.psyber.com/~tcj
3:04 a.m.
On 19 Jan 98 at 11:29, Don Maslin wrote:
On Mon, 19 Jan 1998, William Donzelli wrote:
Can't quarrel with that, but the price difference between an old 3-phase
induction motor and an MG set can be rather impressive!
- don
> Motor-generators are not as bad as most people think - a good one is
> fairly efficient, provides isolation and regulation, and can take a lot of
> electrical abuse. They are just bears to move (done it - not fun).
>
> William Donzelli
> william(a)ans.net
>
>
I used to treasure old electric dryer motors for lathes and such.
They have the starting power to initiate and then kick out to single
phase when up to speed.
ciao larry
lwalkerN0spaM(a)interlog.com
One
scheme that I have seen used to power a 3-phase motor (on a lathe or
such) is to connect a 3-phase motor of comparable rating or higher to the
single-phase mains and also connect all three phases to the motor to be
powered. The motor connected to mains is powered up - it may require a
twist to get it spinning - and when up to a steady speed, the lathe (or
whatever) motor may be powered up. I'm sure that there are some
inefficiencies, but I have seen it work.
Yes, it works, but is quite inefficient. I would venture to say that using
a real motor-generator would be better, if properly maintained.
6:24 a.m.
Can't quarrel with that, but the price difference
between an old 3-phase
induction motor and an MG set can be rather impressive!
I have found with motors and generators the scroungers rule of "be there
at the right place at the right time with a big vehicle" to be quite
effective.
William Donzelli
william(a)ans.net
3:10 p.m.
On Mon, 19 Jan 1998, William Donzelli wrote:
You are right, of course. When skill, cunning, and daring come face to
face with luck and superstition, it is luck and superstition that win
every time! (And being there at the right time suitably equipped is
largely luck.)
- don
donm(a)cts.com
*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*
Don Maslin - Keeper of the Dina-SIG CP/M System Disk Archives
Chairman, Dina-SIG of the San Diego Computer Society
Clinging tenaciously to the trailing edge of technology.
Sysop - Elephant's Graveyard (CP/M) - 619-454-8412
*--*--*--*--*--*--*--*--*--*--*--*--*--*--*--*--*--*--*--*--*--*--*--*--*
see old system support at http://www.psyber.com/~tcj
Can't
quarrel with that, but the price difference between an old 3-phase
induction motor and an MG set can be rather impressive!
I have found with motors and generators the scroungers rule of "be there
at the right place at the right time with a big vehicle" to be quite
effective.
William Donzelli
william(a)ans.net
2:36 p.m.
William Donzelli wrote:
Yes, it works, but is quite inefficient. I would
venture to say that using
a real motor-generator would be better, if properly maintained.
Motor-generators are not as bad as most people think - a good one is
fairly efficient, provides isolation and regulation, and can take a lot of
electrical abuse. They are just bears to move (done it - not fun).
Been there, done that, burned the T-shirt (it was filthy). One nice
thing about the 400 hz 3-phase APUs we had in the USAF is that they
were on wheels. (Of course, powering up a C-5A Galaxy takes a bigger
unit than most mainframes. Even old ones.)
--
Ward Griffiths
Dylan: How many years must some people exist,
before they're allowed to be free?
WDG3rd: If they "must" exist until they're "allowed",
they'll never be free.
10:46 a.m.
William Donzelli wrote:
Been there, done that, burned the T-shirt (it was
filthy). One nice
thing about the 400 hz 3-phase APUs we had in the USAF is that they
were on wheels. (Of course, powering up a C-5A Galaxy takes a bigger
unit than most mainframes. Even old ones.)
Holy! That much required to make the C-5A go?! That is enough to
light and heat everything in a average house or maybe two.
Jason D.
email: jpero(a)cgo.wave.ca
Pero, Jason D.
3:55 p.m.
jpero(a)cgo.wave.ca wrote:
The C-5A Galaxy cargo aircraft was 288 feet long with slightly more
wingspread. The auxilliary power units were capable of powering the
whole damned thing's normal lighting, hydraulics, etc., plus provide
starting power for the four engines (officially the same GE model
used on a 747, but beefed up a bit for the USAF). The main problem
with bringing one home is that they burn a shitload of JP-4 kerosine
jetfuel, and they're louder than fight between a punk and its parents.
--
Ward Griffiths
Dylan: How many years must some people exist,
before they're allowed to be free?
WDG3rd: If they "must" exist until they're "allowed",
they'll never be free.
Been there, done that, burned the T-shirt (it was
filthy). One nice
thing about the 400 hz 3-phase APUs we had in the USAF is that they
were on wheels. (Of course, powering up a C-5A Galaxy takes a bigger
unit than most mainframes. Even old ones.)
Holy! That much required to make the C-5A go?! That is enough to
light and heat everything in a average house or maybe two.
9834
days inactive
9837
days old
11 comments
6 participants
participants (6)
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donm＠cts.com -
gram＠cnct.com -
jpero＠cgo.wave.ca -
jrbrady＠mindspring.com -
lwalker＠mail.interlog.com -
william＠ans.net