# Plugging a surge protector into an UPS



## Chris Blount (Jun 22, 2001)

I've been doing some research on the internet and was wondering what you guys think. Is it safe to plug a surge protector into an UPS? Everywhere I've been reading people are saying that is shouldn't be done because most battery backup outputs are not clean sine waves. Therefore, the surge protector will short some of the battery backup output to ground possibly causing damage and fire to the surge protector and/or the UPS.

Others are saying they have been doing it for years with no problems. 

The reason why I ask is that I just purchased a rather sizeable UPS to backup my home theater. It's an APC 1100 VA (670 watts). Everything is hooked into a surge protector and then into the UPS. Should I switch the surge protector to a regular power strip and let the UPS do the "surge protecting" work? Or am I looking at some serious problems by leaving things the way they are?

I ran a test and cut power to the UPS with my home theater turned on and let it run for about 30 seconds. Everything worked fine.

Thanks!


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## Nick (Apr 23, 2002)

I've run a surge-suppressor power strip out of the backup side of a UPS with no _apparent_ problems. Not very scientific, but in my particular field, the operative saying is: "Whatever works, works!"


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## Rick_EE (Apr 5, 2002)

You could write APS's tech people. They may answer you. It may depend on the surge protector and what method it uses.

I have never put the output of a ups on a scope, so I don't know what the wave looks like. I


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## ERSanders (Apr 24, 2002)

I have a Tripplite 700 on the main PC/moden/MFPrinter, a Tripplite 650 on the primary TV/Satellite/VCR/DVD, a Belkin 500 on the second TV/Satellite/VCR/DVD and an APC 500 on the secondary PC. All have some sort of tapstrip with "cheapie" surge protectors inside. NO PROBLEMAS!

Some of these have been running for three or four years.

I believe the "non-sinewave" is an integrated series of square(ish) waves without significant peaks...thus the surge protectors do not react. Perhaps someone more technically inclined can talk about the theory.


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## Frapp (Apr 23, 2002)

Actually, it is better to purchase a high quality surge protector and plug the UPS into it, thus preventing the UPS from any surge related harm. The protector will also act as a noise filtration system for the UPS/HT system.

If you are using a high quality surge protector such as Panamax ( or others ), it will be warranted by the company and your expensive UPS ( and home theater system ) is fully protected


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## ERSanders (Apr 24, 2002)

A bit of "tech"on the topic: http://www.extremetech.com/article2/0,3973,1155204,00.asp


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## Chris Blount (Jun 22, 2001)

Thanks for the replies guys. I guess I won't worry about it for now. 

ERSanders,

Very interesting article. Thanks for posting the link. My new UPS puts out the "stepped wave" so it shouldn't be too much of a problem for my home theater stuff.


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## aaronwt (Aug 14, 2003)

I've had my 4 UPS's(for my Home theater) plugged into my Monster Surge protector for about 2 years now without any problems.


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