Big UPS (Uninterruptable Power Supply)

I'm getting a pacemaker next week. I work in computers. Our server room has a very large UPS (uninterrupted power supply), with at least 2 very large batteries. Has anyone heard of problems with UPSes and/or knows *how* to find out whether there is a problem? I realize that it depends on the type of PM & UPS, so I'm just asking for tips on how to check this out. I plan to talk to our UPS supplier tomorrow, but I'm not hopeful that he'll know.

In addition, in a different place, we have an electrical generator that powers our server room when we lose electricity. I have the same question about it.

Thanks!

6 Comments

other reply

by Tracey_E - 2012-10-15 08:10:29

See my reply to your other question. A big UPS may put you in test mode. I have a UPS right next to my desk, it's overkill for a home UPS but probably still smaller than what your work has. I've never noticed a problem. Generators can interfere, too. We live in a hurricane zone so have a home generator. I've been told not to get right on top of it but nothing happened when I did. I didn't waste any time doing what I needed to do then backing away, but I didn't notice anything. I'm fully dependent so it wouldn't take long for me to notice a change. Just proceed with caution until you see how you feel.

What a magnet does... there is a switch in the pm. A magnet will pull the switch closed and put it in test mode. It will pace steadily at your minimum rate when closed, so it won't go up and down as needed, just stays right there at 60 (or wherever it's set). As soon as the magnet is removed, the switch opens and it goes back to doing its thing.

Judging by your job, I'm going to guess you like toys. Cell phones, ipods, ipads, gaming systems, routers... none of those cause problems. Some drs say to stay 6" away, to use your cell phone on the opposite side. I ignore all that advice :o) I run with my ipod clipped over my pm, I hold my cell with my shoulder, I read in bed with my ipad (complete with magnetic cover) propped on my chest. I've been paced almost 20 years and have never found anything that affects it.

No problem

by ebfox - 2012-10-15 08:10:42

I manage a group that performs building maintenance for a large utility and my office is in Data Center. Daily I am in close proximity to very large UPS systems (also generators, chillers, pumps, motors, and various other electrical infrastructure) and I have never had any problem. I discussed my PM with several electrical engineers and they basically said that if a piece of equipment was generating an electrical field powerful enough to impact my PM, that equipment would probably be malfunctioning.

So don't worry about it-

EB

Rule of thumb for electrical gizmos

by donr - 2012-10-15 11:10:39

Cecil can tell you where the upper limit is on them affecting your PM. He's been there in an industrial environment.

I very highly doubt that you have the power, voltages & amperages that can affect your PM.

My experience is that you get your PM w/i 6 inches of a 240 Volt, 30 amp cable running full power through it, you will feel it. Happened top me once & I darned near fell off a ladder.

Getting inside a 440 V control center MAY cause you trouble, so be wary of them.

I know of nothing in the computer fields that will operate w/ those levels of power.

Also - all computer gizmos have to meet FCC interference rules on stray field generation/emission/radiation, so you are inherently protected. The UPS' fall into that category. No battery ever affected a PM unless it was connected to something generating an uncontrolled magnetic field.

You are safe - but smart to ask.

Don

I agree

by ElectricFrank - 2012-10-16 02:10:19

EB has the right idea about only a malfunction of the UPS causing interference. Any loss of energy outside the UPS is a reduction of its efficiency, and also would shorten the backup time. In todays market that's a No No.

Don has lots of experience with interference. He runs around and lays on top of power line xformers and other goodies.

I'm not so careful myself either. I carried the large woofer in from my trailer after camping. Big magnet that collects paper clips on the outside, but my pacer is happy. I'm 100% paced and would immediately notice if it crashed.

frank

I'm confused

by ElectricFrank - 2012-10-17 02:10:18

I'm an electronic engineer and been in the field since the 1950's. Since when will 12 volts give you a shock? I just tried one hand on each terminal of a 12V battery right now, and don't feel anything. A 24V aircraft battery would tingle a bit if my hands were wet. Now getting a nasty burn from a short circuit on a battery is another matter. I wonder if the special gloves for a 12V battery was part of some OSHA regulation.

In my early days I worked with vacuum tube circuits where 300-500V was typical. Then there was the 10,000V @ 1A radar klystron. It could ruin your whole day if touched.

cheers,

frank

Shocks from batteries

by donr - 2012-10-17 04:10:27

Frank: Ever get a shock through a cut? It gives you a jolt from Heck.

I've had it happen & was surprised at the dramatic result.

Once upon a time in an electronics lab at NMSU I took a B+ plate pwr supply shock from my fingers to forearm - forearm was resting on the steel edge of the masonite covered lab table. IIRC, this was an "Acorn" tube w/ a current capability of only a few milliamps. All I felt was a surprise sharp tingle. Must have been a high resistance between the table & the Pwr supply. I had a fresh scratch on my arm & a few minutes later took the same shock through the scratch. This time it got my attention. I jumped rather sharply.

A bit off topic, my experience w/ batteries is the same as yours. I don't think that a 6 or 12 V battery has enough potential to break down the skin's relatively high resistance. BUT... I wonder if through open skin, directly into body electrolytes, they could give you a sensible shock.

One thing is fer shure, however - I would NOT want the results of an automotive battery discharging into my bod. Once it achieved skin resistance breakdown, 250 amps would wreak havoc.

Don

You know you're wired when...

You have rhythm.

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