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Electrician's advice wanted: safely lifting ground

Hi all,

I've got a ground loop in my system between the preamp and multiple amps. The cheater plug experiment on the amp power cords not only solves the hum but also lowers the noise floor a bit more. So I would like to do this correctly in a safer, more permanent way.

Bringing all of the power cords in the system to one socket helped also but isn't as quiet as with the grounds lifted.

Can I change the circuit breaker to a GFIC and then tie ground to neutral at the wall socket so that there are no adapters involved? If this isn't the way to go please advise on what is. Even if I don't do this myself I'd like to know so that I can talk with an electrician.

Thanks
dan_ed
sid42
302 posts
 
So what's wrong with the cheater plugs? Parasound amps were noted for having to use cheaters to avoid the hum. A GFCI isn't going to change anything. Gound wire and neutral wire are tied together in the panel anyway, technically.
dan_ed OP
2,451 posts
 
It is not safe. Thanks anyway, I got the answer and a better solution. :-) There is a ground wire that runs between the grd at the input connectors and over to a chassis ground near the ac inlet. I removed that connection and things are every bit as quiet as with the cheater plugs. I'll get a switch to mount on the back and use that as a grd lift. The power supply is still grounded and all is well. Happy feet!
kijanki's avatar
kijanki
4,446 posts
 
Dan_ed - If device was designed with grounded chassis removing this ground creates danger of high voltage appearing on the metal and killing somebody. Yes, a lot of things would have to go wrong but that's how accidents happen. I'm not sure if GFCI can legally replace ground but at least gives you some protection. Imagine that hot 110V wire got loose and touches case inside while person places hand on the case touching another piece of equipment that is grounded. Current will flow thru the body but won't return to GFCI Neutral. GFCI will "see" different currents coming out and returning and will switch off.
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