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Running GC or GC/MS on a UPS
Posted: Thu Oct 05, 2006 12:33 pm
by Schmitty
Does anyone run there 6890s on uninterruptible power supplies? If so, what model do you recommend?
I have three 6890/5973 with Chemstation/PC/monitor combinations that I would like to guarantee never to turn off. We have been having problems with power…having it turn off for 3-5 seconds all the way up to 10-15 minutes.
I’m sure everything is running off of 110/120V outlets, but the 6890s have a 20A type plug.
Thanks!

Re: Running GC or GC/MS on a UPS
Posted: Thu Oct 05, 2006 1:00 pm
by pi3832
I’m sure everything is running off of 110/120V outlets, but the 6890s have a 20A type plug.
And therein lies the rub. I'd be surprised if you can find a UPS that can handle 20 amps for any appreciable length of time. I think you'd need a actual back-up generator, and even then you're going to get some nasty power belches.
Personally, I'd put just the computers on a UPS. That way you won't loose the method.
A plant I worked at years ago had fairly regular power glitches, and I never had any problem other than losing the current run. Well, that and having to climb up into the mezzanine to reset the power conditioner.
Posted: Thu Oct 05, 2006 1:56 pm
by Peter Apps
Hi Schmitty
The problem with having GCs on UPS is their large power demands when they are heating their ovens rapidly. You can get UPSs to cater for any power draw that you want, but the more you want the more they cost.
Protecting just the computer at least saves the data up to the point where the GC cuts out. Maintaining power to the MS keeps its under vacuum so you do not have a pump down delay when the power comes back on.
Some UPS - computer combinations can be programmed to do an orderly shut down when mains power fails, perhaps you can get the same thing set up on the GCs. You might even be able to write a macro on Chemstation to get the sequence running again once the power is up.
If you work out a way of doing this, please post it
Peter
Posted: Thu Oct 05, 2006 5:04 pm
by Schmitty
Yeah, I am well aware of the problems associated with this proposed set-up. I was hoping someone had figured it out already
I will look through the APC, CDW and eBay websites to see if I can find something suitable. My manager is not uninclined to spend 5-10k on this, so there should be a solution out there.
We do have generators, but they leave something to be desired...
Posted: Thu Oct 05, 2006 5:16 pm
by pi3832
We do have generators, but they leave something to be desired...
You might be able to use a UPS to just bridge the time between the power failure and the generator coming on line.
Googling for a UPS with a
5-20R receptical on it gives, e.g., this:
http://www.provantage.com/eaton-powerwa ... XID17C.htm.
The $2000 price tag is outside of my budget, but apparently it may be inside yours.
Posted: Fri Oct 06, 2006 2:38 am
by Schmitty
That looks like something that would work. But since the power consumption could be:
GC 20A
MS 10A
Computer+monitor 5A
I would be looking for something that could supply 4KVA for 15-30 minutes per setup, or 12KVA for all three instruments (they are all on the same bench). There are some good options on that website, however. Thanks for the links.
I am guessing that since the power is conditioned by the UPS that the electricity is inherently *better* than a regular outlet and I wouldn't have to worry about the electronics degrading faster...?
Posted: Fri Oct 06, 2006 12:07 pm
by pi3832
I am guessing that since the power is conditioned by the UPS that the electricity is inherently *better* than a regular outlet and I wouldn't have to worry about the electronics degrading faster...?
As I understand it the conditioned power doesn't increase longevity as much as it reduces noise. In theory, you'll have a higher signal:noise ratio with clean electricity.
And, again as I understand it, not all UPSs condition the power. Cutting in when the the voltage is high or low doesn't really clean up the line noise.