How to tell if a Surge Suppressor is Working?
 

I have cheap surge supressors, and I am not complaining, but how do you know these things are still working. Some don't have a light of any kind. Most have a glowing red light at the switch but is this just to tell me its getting juice? I know MOVs wear out so that's why I'm asking. Some of these I've had for several years.

Are you sure they are even surge protectors? They could simply be power strips. If they don't have a light or a reset button, they are just power strips.

Honestly, if you have any doubts about them, you are better off just buying new ones. There is no reasonable way of testing them, at least, not without dismantling the whole thing.

I agree there. And if you're interested in protection your hardware and software from damage, I would highly recommend a ups, which will regulate your power in the event of power fluctuations, and at the same time providing time to properly bring your PC down. A surge suppressor only flips off when a surge of sufficient proportion is received.

Thanks for the info -- had always wondered -- but how do we know the new ones are any good?

You mean like a manufacturer defect? I suppose to a degree you have to just trust in the manufacturer's QA. Technically speaking you can open up a surge protector and measure the voltage drop in each individual MOV, but of course then you void the warranty and presumably any guarantee the manufacturer has about reimbursing you for damaged hardware.

Each surge protector should be rated at the amount of energy it can dissipate, usually in Joules or kJ. The higher that number, the lower the chances that your equipment will be fried. There's also a guarantee with many of them for a certain amount. I usually buy the best I can find for my computer, simply because it costs less to replace the surge protector than the computer. One way to do it is estimate the cost of replacing your system, compare with the money on the guarantee.

I buy somewhat cheaper ones for other electronics.

Really, I've never had a surge protector fail, no matter how cheap. I bought one 15 years ago, still working fine.

How do you know they haven't failed? Is it that you have had measurable spikes that you know they've protected your equipment from, or that they still provide power to you stuff? 2 different services, and the 2nd can work when the 1st has failed.

How do you know they haven't failed? Is it that you have had measurable spikes that you know they've protected your equipment from, or that they still provide power to you stuff? 2 different services, and the 2nd can work when the 1st has failed.

Yes, we've had numerous black-outs, brown-outs, spikes, storms, etc. and there were no problems.

Usually surge protectors, especially decent ones must have an indicator light, or many times two: one for power and one for the MOVs, sometimes even one for ground. If all lights are on, then it's working. Most of the ones I own have 2 lights one for power and one for MOVs usually labeled "protected" or something like that.

I think this article is relevant and informative:
http://www.howstuffworks.com/surge-protector.htm

Also, it depends on what you expect to happen, if it's just a spike or surge most any surge protector can handle them, but if it is lightning, even close by, it might be a problem. I've actually had a satellite box fried by lightning, but not via the power line, but via the coax cable, because it wasn't plugged in to the power line, just to the coax cable.

Hi,

Lightning can cause nightmares literally!

I've lost a lot of equipment here on the farm. Isolation is the main thing to focus on. My electric fence is a big lightning rod and causes more problems but it is necessary with stock. Phone systems are one of the weakest points in every home that everyone seems to overlook. Good ground techniques for the system are very important. A few years ago our place had a direct hit and it turned out to be both the phone line and power. The only systems that weren't damaged were the ones unplugged.

Surge protection with strips will prevent damage from transients not direct lightning strikes, just arc over. UPS if designed properly will switch over and off line. But that too can be arced over if the contact system is not designed properly.

I could list the equipment lost from lightning but that would do no one any good. If you know there's a storm or watch then unplug the equipment since that is the only insurance that can be guaranteed to work. As for the MOV cheap strips, if you have a lot of inductive equipment within proximity of the electronics then a good filter design that uses MOV & a Pi filter will prevent spurious problems from being injected. Just don't plug the electronics on the same circuit as the refrigerator or like equipment.

I do use the single socket MOV that has a visual window to inspect physically. Easy to test for failure and cheaper to replace. But these are used to prevent the spurious problems not much when the power fluctuates or RFI. I use UPS for that but these to can be damaged from repeated strikes or large injection.
:hattip: