[CountChoculaBot]

I have a severe ground loop problem within my rig setup, which using cheater plugs on my gaming PC, HDTV, and PS3 (about $2500 worth of stuff) solved. This is *only* a stopgap, since my future DAC will have isolation transformers on the inputs to eliminate the ground loop. It mostly helps me with the temporary inconvenience of having to unplug an optical cable from my PC to my PS3 whenever I feel like playing it (with the cheater plugs, I can keep a coaxial cable connected to my PC, and an optical to the PS3).

It'll be about a month or so before the new DAC will be in my possession. Until then, is it a huge risk to my electronics to be using these cheater plugs?

 

[mrarroyo]

I would only use the cheater plug for a very short temporary solution. Now if you can ground it using the loop at the end you may leave it longer.

 

[Uncle Erik]

Just buy an external isolation transformer for $20 or $30. You can find them at electronics hobbyist shops, eBay, Nebraska Surplus, and many other places.

Don't use the cheater plugs. They're unsafe.

 

[Steve Eddy]

Quote:

Originally Posted by Uncle Erik /img/forum/go_quote.gif Don't use the cheater plugs. They're unsafe.

And they're not even cheater plugs.

What people refer to as cheater plugs are in fact specifically intended to PROVIDE a safety ground rather than DEFEAT it.

se

 

[mminutel]

Sorry to take over your thread, but it seems you have had your question answered. What would you guys say to a person who's house wiring doesn't have ground? The downstairs of my college house has three prong, but the upstairs where our bedrooms are is only setup for two prong.

 

[Steve Eddy]

Quote:

Originally Posted by mminutel /img/forum/go_quote.gif Sorry to take over your thread, but it seems you have had your question answered. What would you guys say to a person who's house wiring doesn't have ground? The downstairs of my college house has three prong, but the upstairs where our bedrooms are is only setup for two prong.

Then you would use what people otherwise call a "cheater plug."

se

 

[mminutel]

Yeah. That's what I am forced to use now, but I was just wondering if there was a better solution (other than running new electricity) to protect my stuff.

 

[sparkplug]

Would only use them if the appliance is double insulated, then it's safe to do so.

Otherwise those donut shaped chokes or ferrite rings around the cables are an inexpensive way to stop RF noise and EMI noise, which seems to solve most ground loop problems.

Finally a ground loop isolator box is the final solution and costs about £30 for a good one.

 

[mrarroyo]

Quote:

Originally Posted by Uncle Erik /img/forum/go_quote.gif Just buy an external isolation transformer for $20 or $30. You can find them at electronics hobbyist shops, eBay, Nebraska Surplus, and many other places. Don't use the cheater plugs. They're unsafe.

That is not necessarily correct. If you look at the picture I posted it has a copper ring to be screwed using the center screw of an outlet. Many older homes have a ground going to the box/conduit and thus save to use.

 

[Lazarus Short]

Quote:

Originally Posted by mminutel /img/forum/go_quote.gif Yeah. That's what I am forced to use now, but I was just wondering if there was a better solution (other than running new electricity) to protect my stuff.

If possible, drive a ground rod [copper plated steel - don't use rebar] into the ground, put the ground clamp on it, and run a ground wire to your gear. A cold water pipe [but not a plastic pipe] will suffice. Make sure the connection is clean and stays that way. That's what I did for my A/V system in a 50+ year old house, where many outlets are still two prong. My main system, happily, is on a twenty amp dedicated circuit.

 

[Steve Eddy]

Quote:

Originally Posted by Lazarus Short /img/forum/go_quote.gif If possible, drive a ground rod [copper plated steel - don't use rebar] into the ground, put the ground clamp on it, and run a ground wire to your gear. A cold water pipe [but not a plastic pipe] will suffice. Make sure the connection is clean and stays that way. That's what I did for my A/V system in a 50+ year old house, where many outlets are still two prong. My main system, happily, is on a twenty amp dedicated circuit.

That is NOT a good idea. The safety ground should ONLY return to the neutral at the service panel. Keep in mind that the ONLY purpose of the safety ground is safety, i.e. to provide a low impedance return path back to neutral in the event of a fault.

Using a ground rod or tied to a water pipe WILL NOT necessarily provide sufficiently low resistance to neutral.

se

 

[Lazarus Short]

Quote:

Originally Posted by Koyaan I. Sqatsi /img/forum/go_quote.gif That is NOT a good idea. The safety ground should ONLY return to the neutral at the service panel. Keep in mind that the ONLY purpose of the safety ground is safety, i.e. to provide a low impedance return path back to neutral in the event of a fault. Using a ground rod or tied to a water pipe WILL NOT necessarily provide sufficiently low resistance to neutral. se

Thanks, what I said must be the old way of doing it. Maybe I will re-wire the ground per your advise. However, the power strip for my A/V system has lights that indicate that the ground is good.

 

[Bones13]

I think you missed one of the points above. There may well be a third "ground" wire coming to your 2 prong only plugs. This wire is usually found attached to the metal box into which the plug is placed. It may be that you only need to have some of your plugs rewired to correct 3 prong plugs, as the wires may already be in place. Obviously not a guarantee.

 

[scompton]

In some old houses, like mine, the house is wired with BX cable and the ground can be though the metal conduit. It's not as ideal as having a ground wire back to the panel, but I believe it is acceptable in the national code. Surge suppressors may not work, or their warranty may be void if plugged into an outlet grounded this way.

This is also true if grounding to a box that's grounded. If you have a ground wire coming into a metal box, ground the box and the outlet with wires connected to the ground wire with a wire nut.

 

[regal]

Count,

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