On India's power outage

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On 8/16/2012 6:47 AM, snipped-for-privacy@att.bizzzzzzzzzzzz wrote:

The one I was involved with back in 1988 was a Cray X-MP at the mission control center for SDI tests at The Quajalein Missile Range. The Cray I think, had Freon cooling system interfaced with the building's chilled water system. There were a number of DEC VAX systems too and the Liebert air conditioning units were blowing down into the raised flooring system. It was a very interesting experience to be involved in that project during those days. ^_^
TDD
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On Thu, 16 Aug 2012 08:46:55 -0500, The Daring Dufas

Right, but not air-cooled. Air just doesn't have the necessary specific heat to do the job, no matter how much is moved.
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On 8/16/2012 9:51 AM, snipped-for-privacy@att.bizzzzzzzzzzzz wrote:

The DEC computers and other gear was air cooled. I think there was an atomic clock in one of the rooms next to mission control. It was all raised flooring air conditioned by the Liebert units blowing air into the raised floor. GEEZ! There was a lot of wiring in that darn place. O_o
TDD
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On Thu, 16 Aug 2012 18:51:58 -0500, The Daring Dufas

DEC never made a "supercomputer".
Moons ago, we had a test floor with a bunch of Lieberts on it for cooling the ATE equipment. Some joker laid out the raised floor with grates under the desks where the operator's consoles were. For some reason the women had problems with that idea.
Once, over the July 4 weekend, the floor was completely shut down. On Monday, one of the managers came in to start the AC back up so it would be cool by start of work Tuesday. Sometime later, the thermostat stuck. Since there was no heat load (all the ATE systems were still powered down), it got *cold*. Tuesday morning people noticed that it was *cold*, so the moron manager opened all the doors to warm it up. Since it was humid (July, remember) water started condensing everywhere. Water was running out of the ceiling tiles and every piece of test equipment was wet, and visibly growing rust. Three of these systems were worth $2.5M each, and another half-dozen were $1M each. Of course rust wasn't covered in the service contracts (environmental control was a requirement). Ice formed on the steel raised floor and people were falling all over. Needless to say, it was a mess. We laughed our asses off. ;-)
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On 8/16/2012 9:28 PM, snipped-for-privacy@att.bizzzzzzzzzzzz wrote:

Perhaps you misunderstood me, the DEC gear was in the same room as the Cray X-MP. I remember a separate cabinet that coupled the Cray's cooling system with the building's chilled water system. I distinctly remember seeing a 30lb jug of R-22 next to the cabinet. O_o
TDD
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On Thu, 16 Aug 2012 22:32:23 -0500, The Daring Dufas

Yes, I misunderstood you incorrectly. Lieberts do use chilled water to cool air, precisely because water has a fairly high specific heat (and it's cheap). I don't remember if the X-MP uses boiling freon, or not, but the reason it's used is because it's inert (and the boiling point can be engineered). In the '70s, we used freon to cool chips. A 100-chip, about 4" x 4" module was encapsulated in freon. On the back side was a water-freon heat exchanger. The chips on a vertical surface inside the module, covered in freon. The freon was set to boil at 85C, the optimum temperature for the circuits. Neat stuff, until they "discovered" that boiling was the opposite of distilling. All the bad stuff gets left behind (can you say, "black plague"?).
That idea was junked in favor of one that use helium. ;-)
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On 8/16/2012 10:46 PM, snipped-for-privacy@att.bizzzzzzzzzzzz wrote:

Was the freon R-11 perchance? R-11 is a liquid at cool room temps. I think it boils at about 75F and you can get a thrill by dipping your hand into the liquid because it will come out clean. The stuff was often used as a cleaner instead of a refrigerant in centrifugal chillers. I believe it murdered more cute little ozones than any other refrigerant so production stopped in 96. Being a good cleaner, was the high boiling point Freon you were using dissolving elements in the modules? O_o
Oh yea, did you have problems sealing in the Helium? ^_^
TDD
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On Fri, 17 Aug 2012 02:01:27 -0500, The Daring Dufas

FC86 (I have no idea why I remember that). the boiling point was right at 85C, IIRC.

No, it wasn't dissolving anything it just couldn't be made clean enough. Any residual contamination was left right on the chips, in the worst possible location.

You bet. It even diffuses through the aluminum module. They were used in every IBM mainframe for more than ten years, though.
http://www-03.ibm.com/ibm/history/exhibits/vintage/vintage_4506VV2137.html
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I worked at Apollo goldstone. The one piece of equipment I was working on was a beast, with different kinds of circuits. That monster caused me a lot of worries. It also made the operating room colder, because they intensified the cooling to the whole building just to cool my gear. Also really cold to crawl underfloor. Most all equipment was noisy back then. A pdp 8/I had four 100 cfm fans. that was working at dec. When the NASA station shut down the air handlers, it sure got quiet.
I pushed a button one day and the whole station shut down. 75 hp motor shorted blowing the first, then the second breaker which was 4 miles away. It's that, did I do something wrong feeling.
Greg
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On 8/16/2012 10:02 PM, gregz wrote:

On one of the islands on the North end of the atoll, there was older computer equipment at the deep space tracking radar and the backup power supplies were motor/generator sets with big flywheels. If the power plant went down, the big flywheels kept things on while a backup generator could be started up. There was a lot of really cool old stuff out there at the missile range. ^_^
TDD
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I think some had freon actually running through the circuits with direct contact. The problem is concentrated heat much like a hot CPU chip today.
Greg
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wrote:

Whether it's running at 100% or not wasn't material to the discussion. I only gave it as one case of several possibilities in analyzing whether the utility turning it off on you is possible with it actually benefitting the utility without raising the temperature in the house.
And I'd say it's not necessarily incorrectly sized if it's running close to 100% on one of the historically hottest days

No, they don't. Do you really expect the power company to come out and do a full by the book load calculation? They can install their radio controlled widget in 30 mins, which achieves their objective to shed load when needed. And if they did the load calc, what would the point be to not installing the device anyway? Like somebody is going to say, "Gee, to get that device that really benefits the power company, I have to install a new AC system, so let's do it? "
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On 08/08/2012 01:50 PM, snipped-for-privacy@att.bizzzzzzzzzzzz wrote:

Shifting the draw by ten minutes will make an effect if there are tens of thousands of units controlled centrally. In such a situation, staggering compressor draw will serve to even out the load across both a local, as well as a larger area. Since the grid is already pushed pretty far into its capacity, this helps to alleviate brownout conditions, which, from my understanding, is the rationale behind their scheme.
Jon
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On Wed, 15 Aug 2012 14:53:00 -0700, Jon Danniken

Sure, you push the load back ten minutes. Now what?
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On Wed, 15 Aug 2012 22:23:48 -0400, " snipped-for-privacy@att.bizzzzzzzzzzzz"

I imagine they do that in blocks and each gets a ten minute segment. Peak load is usually between about noon and 5 PM so it would be a juggle during that period. Once factories go off line about 4 and offices close at 5, no need to juggle.
Of course, all any of us are doing is guessing. It would be interesting to see the real method and results.
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So what? Every one of those ACs that went off-line will use that much more power after coming back on line.

Ten minutes isn't going to do it. If they leave them off for hours, perhaps. Then the delta-T is reduced, saving something.
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wrote:

We've been getting solicitations for this PSE&G program: <http://www.pseg.com/home/save/manage_costs/cool_customer.jsp It sounds attractive to the customer and features 15 min off periods when PSE&G experiences too high demand (as they define it). I called them once or twice and they never responded. Then the question was posed by the person in charge why should we trust them? That was the end.
Is there anyone here with experience with the PSE&G program?
--
Best regards
Han
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I have the JCPL unit. But since they rarely activate it and I have no idea when they do it, there is no way to know. I might not even be around.
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wrote: <snip>

<snip>
Could you tell me more about what you got? Just the switch they remotely activate to shut off the AC? Or the whole fancy thermostat thing? Did they give you the promised credits? Was the installation done professionally?
--
Best regards
Han
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It was on the AC when I bought the house 20 years ago. It's just a radio controlled switch that's mounted on the AC compressor. Orignally they paid a flat fee, think it was about $25 a year. Recently they switched to paying I think $2 per activation. And they rarely activate it, so I get even less money. The only way I'd know is looking at bills. I guess there are a couple lights on it and you could also notice that the blower continues to run with the compressor stopped, but I've never noticed that actually happen. But then again, I'm not paying that much attention to it either.
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