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Household Surge Protectors - Good or Bad?

A few weeks ago I had a surge protector installed in my breaker panel.

It was a new variey I had not seen before, in that it took the place of two standard sizede breakers and connected to both phases of the breaker panel supply

Since then we’ve had had a couple of power outtages and all the household devices kept running upon power restoraton - so far so good :-)

This past week I had reason to disconnect power and speaker cables to loan to a friend for audition.

Afterwards I reconnected the power cables to the amp and powered up.

NOTE: the system is on a dedicated line - it’s breaker was not touched by the install

Immediately I noticed a hum from the amp, where previously there had been none - even at full volume with the phono stage selected.

After lots of analysis and testing, I remembered the installation of the Surge protector.

I measured the impedance between the ground and the neutral and found around 5 ohms of resistance.

To temporarily get over the hum I have connected the neutral side of the inputs to a common earth tap on the power distribution box - it has worked like a charm - i.e. until I can get the electrician back here to fix the real issue.

So my question:
- Is this just sloppy work? - I’m assuming that the neutral of the dedicated line was disconnected and not reconnected correctly, OR
- do ALL housewide surge protectors such as the one I have had instlaled always present with this problem?

Thanks for any feedback

williewonka
erik_squires
16,049 posts
 

If you turn off the 2 pole breaker in the electrical panel the SPD (Surge Protection Device) is connected to, the SPD will be disconnected, isolated, from the electrical panel.

That is not how this type of surge protector is connected, if it is what I'm thinking of, like this model:

https://www.alliedelec.com/square-d-qo2175sb/70060775/?mkwid=sUgs25dac&pcrid=30980760979&pkw...

It's impossible to tell from the pic, but the surge protector itself takes 2 spots. In this way it is just like a 2-pole breaker. It connects directly to both phases with no interceding breakers. There is a tail to be attached to the panel's neutral.

In short, there is no breaker on the protector, and no breaker that is assigned to power the protector either.  Should the surge protector itself short the panel's main breaker will have to trip. 

There's no way for a homeowner to "turnt it off" short of removing the panel cover and pulling it off the panel.

Best,

E
erik_squires
16,049 posts
 
Should also point out, that the electrical panel is the ideal place for this type of surge protector. 

In the room however you want a series mode surge protector instead, like Furman, SurgeX and select others provide. 
erik_squires
16,049 posts
 
Also, because of the way in which this type of surge protector connects , it is NOT possible for it to lift the ground like the OP has measured. It has nothing to do with ground.

It might be possible the electrician did something while installing it, or more likely, that something has gone bad independently of this. The way this works is that the neutral and ground may only tie together at 1 point in the entire home. So, it could be a disconnected ground or neutral anywhere from the listening room back to the service entrance. 

Best,

E
elevick
2,636 posts
 
FYI-I have had a whole house surge for 15 years.  It only trips on very large spikes such as a transformer blowing at the pole.  Smaller spikes always get through.  Also, even with big spikes it is not nearly as sensitive as even the lower priced PS Audio stuff.  You should still use either a conditioner or surge at your system.  Several times I have had my PS blow while the whole house did not.  
There is nothing wrong with my whole house surge, it just wasn't designed for expensive audio.
dweller's avatar
dweller
3,781 posts
 
@erik_squires - Thanks for the sympathy. After giving it some thought, I think it was a whole-house GFI (ground fault interrupter) not a surge protector. It would pop open at least once a day.
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