On Fri, 20 Jul 2007 01:27:47 GMT, in message , "Michael A. Terrell" scribed:
The Falcon SSG500 has an efficiency of 85%, and might be the model Cap'n Doodo is referencing. Couldn't find a price in a cursory search, but it seems Allis-Chalmers is pleased with the product:
Brings to mind the old saw, "If you have to ask, you can't afford it."
On Thu, 19 Jul 2007 18:04:48 -0400, in message , Jamie scribed:
Yes, but I'm afraid neither you nor the Cap'n fully understand. As the other sub-thread is showing, the above description of how the UPS operates is that of an "online" UPS. Unless you know that you have an online model, you can't rely on the description given being accurate. Here's a site that sells UPS:
Note that there are three types listed: online, standby, and line-interactive. The line-interactive is still a standby UPS, but has faster response to failure.
Note that the Powerware Prestige 650 can be had new for about $550, and give online performance and true sine wave output. (That's another point about UPS - the output. Some UPS inverters have a very dirty stepped sine output.) Efficiency is probably around 90% (I found 93% listed for their
3000VA unit).So, in order for understanding to be complete, one must know what unit one possesses. This is a really good page for study:
On Thu, 19 Jul 2007 18:11:07 -0400, in message , Jamie scribed:
I would be very surprised to learn that your online UPS is not synced to the line feed. Can you verify that via make and model? Thanks.
On Sun, 22 Jul 2007 02:41:26 GMT, in message , "Michael A. Terrell" scribed:
Ah yes, of course, the batteries. APC makes a good standby UPS, but expect to change its battery every three years, and that's not terribly cheap. Two years ago I hired on at a new company. One of my first engineering decisions involved an UPS. The technician wanted to throw out a small APC unit when it stopped functioning correctly. I asked him when was the last time he changed the battery. He replied, "Battery?" Not that he was a bad tech, he just had a limited knowledge base.
My first APC last for over five years on the OEM battery. Sine then, I've had so many given to me that I haven't needed to buy batteries in over 10 year. Yes, the batteries do fail, especially when the electric goes out often, and the computer isn't set up to shut down.
Right now I have at least 12 spares with usable batteries, and I could probably get several hundred more per year, for free. Replacement batteries aren't that bad, bought in bulk. APC is very high, compared to OEM and surplus sources. I used to pick up used Gates battery packs from a Diebold repair center, and sell them to amateur radio operators for standby power. they still bug me for more cheap batteries, but the source is gone. I also have several new 17 AH 12 VDC gel cells from those portable starter packs for cars. I'm tempted to use them as external batteries on a pair of old 1000 VA APC UPS I have in storage for my server and web design computers. The 650 VA APC can't handle the computer and HP 1130 monitor, and odds and ends in my office.
-- Service to my country? Been there, Done that, and I\'ve got my DD214 to prove it. Member of DAV #85. Michael A. Terrell Central Florida
V Sat, 21 Jul 2007 19:57:15 -0800, Charlie Siegrist napsal(a):
That's the exact point, and what I was looking for. Don't assume everyone who asks a question is ignorant...
And don't assume that efficiency and cost (as in the other subthread) are an issue... (15KW generator running a machine that's a quarter mile long
- do you think anyone is going to care if a 500VA UPS is 85% efficient? Or that it costs US$500?)
:-)
--Yan
On Tue, 24 Jul 2007 14:48:43 -0000, in message , Captain Dondo scribed:
I try never to make such an assumption. At this point in the conversation, however, I have no idea whatsoever what your exact point is, or for what you are looking.
Yes, actually, cost and efficiency are a consideration in any engineering procurement decision. That's not an assumption, that's a fact. Budgets are not bottomless, as much as an engineering team might want them to be. And I wonder, what good is a 500VA UPS in maintaining a 15KW load?
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