Surge protector for 20amp circuit

Discussion in 'Home Theater Projects' started by Joe, May 26, 2003.

  1. Joe

    Joe Stunt Coordinator

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    All I need is a surge protector for a single 20amp ciruit that will not limit current to my amp. No conditioning or other things needed.

    Does the run of the mill Belkin surge protector do this without limiting current? Thanks.
     
  2. Chu Gai

    Chu Gai Lead Actor

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    Any MOV or Silicon Avalanche Diode based system, which implies that it's a parallel mode device, will act as you're thinking. As to whether these devices also include other components such as EMI suppression that are wired in series I don't know. I think it's enormously speculative to think that their presence somehow causes sonic degradation.
    If you have your own home a generally prudent course of action would be to install a whole house surge protection device, typically done by an electrician, that is located at the AC mains.

    If the whole house approach is not your thing, consider replacing your receptacle with one that does incorporate transient suppression such as the following one from Leviton. That's a more elegant approach that also gives you a more robustly manufactured outlet (industrial grade and all that). That's only an example and likely your local electrical supply house carries equivalent solutions.

    I'm not so sure the Belkin would fit into the 20 amp receptacle btw.
     
  3. Joe

    Joe Stunt Coordinator

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    Thanks for the info. I think the Leviton devices are what I am looking for. Do you think 320 joules are enough?
     
  4. Chu Gai

    Chu Gai Lead Actor

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    No easy answers I'm afraid but allow me to elaborate a bit more.

    The most effective approach is surge protection at the mains followed by local redundancy to address any individual concerns with spikes. So long as your external ground is good (grounding rod) this is the correct approach. At the risk of sounding like a smart-ass, this isn't what I think, this is the correct way to do it.

    Keep in mind that surges aren't your freezer compressor turning on rather they're short but powerful electrical phenomena involving many kiloamps. A surge protector works not by absorbing, but by diverting this energy to ground. Hence when your primary device is located at the AC mains, this ground is outside your residence and it becomes the shortest path. If you choose the Leviton or Belkin or any other surge protector and that's your only one, then ground can be anything. It might be right back down the groundwire and then to the outside. It might be anything else too. Your phone, your microwave, garage door opener, toaster, anywhere that surge can go to ground itself is fair game. It may even choose multiple paths and can conceivable jump wires.

    Let's say you've got just your amp plugged in to a surge protector and nothing else is protected. Since your amp is connected to the rest of your HT system, that amp can still be fried by a surge coming in via the backdoor be it cable, preamp, dvd, whatever.

    So is 320 joules enough? Well that number is an indication of how much energy can strike the surge protector and still have it remain functional. The question then comes, what happens when it becomes non-functional? Does it still continue to pass power or does it fail such that the circuit is now open? If the unit is UL 1449, 2nd edition listed, then I believe it will fail open. That means the protector did it's job...it died...but your equipment is still protected although you're inconvenienced by having to replace it. Personally I don't see that as such a bad thing. Kind of like a Secret Service agent taking a bullet.
    Reading the leviton link I gave you, you'll notice that it does say 2nd edition, hence it should fail open. Personally, I'd confirm that via a phone call to Leviton (I think they've got a toll free #). I urge you to confirm this for yourself and your own peace of mind.

    If you purchase a unit that is 3000 joules, then it'd be able to take a larger hit and/or more smaller hits before it's no longer functional. It's really a lifetime thing. Like I said, I'm assuming that 20 amp circuit you're talking about has got a real 20 amp outlet on it which implies that 15 amp plugs won't mate with it. However, there's no reason why you can't replace that outlet with a 15 amp one whether it's a Leviton or some other.
     

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