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How do I know when a surge protection device has outlived its usefulness?
I have 2 Furman M-8LX units that I used in a small concert hall 3 or 4 times a week for about 4 years.
I also have an Aris 614 unit that I've used in my home studio for at least 20 years (!).
They still distribute power just fine, of course... but can I still depend on these things for surge protection?

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Boswell Sun, 12/27/2015 - 10:32

Most types do degrade in their effectiveness at surge suppression. It will depend on the make of board and how spike-invested your local mains supply is. My studio is relatively quiet with well-behaved mains, but since I do around half my recording on sites where the quality of the mains supplies is unknown, I have to assume they get hit with a wide variety of abuse. Sharing mains supplies with lighting consoles used to be a real dread, but modern ones seem much better behaved.

In my equipment racks I operate a tier system where I replace the top-level surge-protected plugboards (those supplying the most sensitive bits of gear) roughly every year. The replaced ones cascade down to other tiers, and off the bottom end I have a large box filling up with perfectly-serviceable plugboards that I label as non-suppressed and lend to the lighting crews.

DonnyThompson Mon, 12/28/2015 - 01:33

bigsphinx, post: 434707, member: 49531 wrote: Hm. Yeah, maybe I'll dispose of that Aris 614... it's pretty ancient at this point, I can't imagine it's protecting much of anything anymore...

One would think that there would be a way to test these units to see how effective they are, as opposed to just getting rid of them after a certain length of time and frequency of use.

Not that I have the answer to that... but I find it hard to accept that there isn't some way to check them, something more precise and conclusive than just "assuming" that they are faulty or not up to the task, just because they've been used for a few years, and then just tossing them after that period of time... ?

dvdhawk Mon, 12/28/2015 - 09:16

There's really no reason to toss an otherwise good surge protector. The part that will fail is usually the Metal Oxide Varistor on the primary power line. They cost less than a dollar, and are easy to locate and replace for anyone who can solder if they use reasonable high-voltage caution. The biggest problem often is, if the MOV has failed in a spectacular fashion, it will be impossible to read the markings on it. They can scatter, or turn into charcoal from a big surge (like lightning), or on the other end of the spectrum just stop working with no visible signs of damage, from the cumulative damage of everyday spikes.

dvdhawk Mon, 12/28/2015 - 13:20

bigsphinx, post: 434711, member: 49531 wrote: But... if I'm a mere musician, and not an electrician... and very wary of high-voltage situations... that sort of testing (and soldering) is not really an option, unfortunately.

You are right to be VERY wary of electricity. Like any other high-voltage work, I would not recommend anyone undertake this DIY repair project unless they are 100% sure of what they're doing, and the safest methods. Even for those who DO know what they're doing, great care needs to be taken to avoid potentially deadly mistakes. Choosing the right varistor is not always cut and dried either. When they fail they can A) catastrophically go up in flames and leave an obviously open-circuit, or B) they can eventually just gradually reach their limit a little bit at a time and either look perfect and not pass power, or C) look perfect and still pass power - but not limit surges any more. So even if the unit still pass power to all the receptacles, it does not guarantee it's suppressing voltage spikes at all.

All things considered, the M series isn't horribly expensive, so periodically rotating them to less critical jobs, as Boswell does, is a great solution.

Boswell Mon, 12/28/2015 - 15:18

The point about surge protectors is that they can degrade with normal usage over time, and unless they happen to explode under duress there is no visible way to tell how degraded they are. It's a bit like testing car air bags - you could get an idea whether that brand or model degrades over time by testing lots of them, but that doesn't guarantee that any individual bag will still function correctly when needed after several years without destroying it to find out.

dvdhawk Mon, 12/28/2015 - 15:20

Kurt Foster, Kurt that's about it for the cheap dollar-store, wallymart surge-protectors. The ones we pay good money for are usually more than simple Surge Protectors (at least in theory).

There are rack-mount versions of the cheapo power strip, which are nothing more than power distribution. (most brands have an MOV for surge, some do not) You're paying for the metal enclosure.

The next level up would be Power Conditioners, that in addition to MOVs to protect from surges and other over-voltage conditions on the primary power coming in, they have a lot more circuitry between there and the receptacles to filter out EMI and RFI electrical noise. Some of those might even have multiple filter banks and transformer isolated outlets. And you can get power conditioners that will sequentially turn things on/off in the correct order by using delayed relays. Sequencers usually have the capability to be switched on/off from a long distance away through low-voltage contacts and a simple switch to trigger the main relay.

The next step up to Line Voltage Regulators is where it gets really expensive (and heavy). As the name implies, in addition to surge and conditioning, these add regulation that can take just about any input voltage between 90V - 135V and transform it to a solid 120V at the receptacles. Handy if you live somewhere prone to, over-voltage, brown-out conditions, or gig on generators. There are global versions you can use just about anywhere and be pretty safe with input voltages of anywhere from 85-265V. Regardless of 50 or 60Hz, they still putting out stable 120V 60Hz power. Here, on top of all that extra circuitry, you're paying for a heavy gauge enclosure to support the huge transformer(s) inside. These can really set you back price-wise and probably average 100 lbs. or so.

The reputable manufacturers, (Furman, ETA, Tripp-Lite/SL Waber, JuiceGoose, Wattbox) do a decent job telling the consumer which type they're buying.

rmburrow Wed, 11/02/2016 - 19:30

Dvdhawk is correct about Tripp-Lite; the Grainger catalog lists one of their line conditioners (Tripp-Lite p/n LS 606M; Grainger cat. no. 5JK13) which is good for 6 amps 120/240 volts, good enough for preamps or a workstation. Erico makes suppressors that mount on the breaker panel through a knockout. A licensed electrician should install these, especially on non-owned or leased property. Many radio transmitter sites use surge suppressors to protect the transmitter(s) and associated equipment. The panel mounted ones have status LED's that indicate whether the suppressor is operating, or failed (i.e. lightning strike, etc). Prepare to spend a couple hundred bucks plus the electrician's labor on permanently wired suppressors.