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Discussion Starter · #1 ·
Hey guys, just moved to Santa Cruz in my friends house.


The outlets where I want to put my sound system (40" Samsung LCD, Onkyo TXSR506, AV123 ELT525 5.0, SVS PB10-NSD) are only 2 prong.


I have a Power Conditioner/Surge Protector that I use to plug all of my equipment in.


My friend has one of those 3-to-2prong adapters that I could use to plug the power condition/surge protector into the wall, and I was just wondering how safe this is? I just want to make sure my equipment won't be damaged, and that my system is going to get enough power and be safe.


I know nothing about electricity/currents so I'm hoping you guys can give me some insight.


Thanks so much,

Edge
 

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Has your friend had any problems?


I would guess they haven't. I've lived in a few houses and apartments when I was young with 2 conductor wire and never had a problem. Your power conditioner might have a problem not detecting the second ground.
 

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Quote:
Originally Posted by edgeh2o /forum/post/16931185


Hey guys, just moved to Santa Cruz in my friends house.


The outlets where I want to put my sound system (40" Samsung LCD, Onkyo TXSR506, AV123 ELT525 5.0, SVS PB10-NSD) are only 2 prong.


My friend has one of those 3-to-2prong adapters that I could use to plug the power condition/surge protector into the wall, and I was just wondering how safe this is?

One risk is a failure in the equipment causing the case to become hot and sending current through a grounded person; perhaps touching something with a metal case that ties signal and system ground together with some set of interconnected components that have a cable TV or satellite hookup.


When the third prong is grounded the circuit breaker trips as soon as that happens so it's not a problem.


The adapters provide a third lug for grounding so you can still get that behavior.


A working ground fault interrupter will trip in that case. The NEC allows you to install three prong GFCI outlets and mark them "No equipment ground" or three prong outlets with GFCI circuit breakers additionally labeled "GFCI protected".


This isn't as good because GFCI circuits often fail.
 

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i personally wouldn't lift the ground for any extended period of time... but that's me...
 

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Discussion Starter · #5 ·
The power conditioner I have has 4 lights on it that read 'Protection OK' 'Ground OK' 'Unsafe Voltage' and 'DC Trigger'.


When I plugged the power conditioner into a 3-2 prong adapter, and then that in the 2 prong outlet, the Protection OK and DC Trigger lights came on, but no ground.


In the kitchen and other living room, there are 3-prong outlets, and so I then went around the house and plugged the power conditioner into each 3-prong outlet and turned it on to see if the Ground OK light came on, but for each outlet I tried, only the Protection OK and DC Trigger lights came on. Does this mean that none of the outlets in the house(even the 3 prong ones) are grounded?


Knucklehead - No problems so far.


Drew Eckhardt - What do you mean by case? Is equipment failure pretty uncommon? By grounded person do you mean any person standing on the ground?


ccotenj - Excuse my ignorance, but what exactly do you mean by lift the ground?
 

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I have had everything I own plugged in old 2 prong outlets. I never have had a problem. 10 plus yrs with expensive equipment. I do have everything running into a monster power conditioner, it just does not have a grounded circuit.
 

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Just some random thoughts:

a) Modern GFCI receptacles are rather reliable (the new one with LED indicators are maybe the 4th, 5th or 6th generation of GFCI's)

b) GFCI circuit breakers can be a problem in houses with old wires.

c) Power conditioners that dump the noise to the safety ground wire can trip GFCI's.

d) Good power conditioners don't dump the noise to the safety ground wire.

e) Surge protectors may dump the large spikes to the safety ground wire, so if you are using a 2 wire circuit the surge protector has no place to dump too!
 

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Quote:
Originally Posted by edgeh2o /forum/post/16931378


ccotenj - Excuse my ignorance, but what exactly do you mean by lift the ground?

oops, sorry. "lift the ground" = do what you are doing, i.e. use a 3 prong to 2 prong adapter...


again, i wouldn't do it... there's a reason why stuff is grounded... you might use it for 1000 years and never have a problem... you also might zap the crap out of yourself, or (worst case) burn your house down...


safety first...
 

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Discussion Starter · #10 ·
I see... well I need to plug in my stuff, and upgrading the outlet to 3 prong is pretty much out of the question, so for now, I think I need to use an adapter.


My next question is, should I ground the adapter or leave it ungrounded?
 

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You would want to ground the adaptor. By properly grounding the adaptor you are installing a ground for that adaptor only. Much safer than no ground. Otherwise the adaptor would just be an adaptor and your protector would never get a ground signal. The purpose of the metal ring hanging down on the adaptor is to attach it to ground.
 

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Quote:
Originally Posted by edgeh2o /forum/post/16931378


When I plugged the power conditioner into a 3-2 prong adapter, and then that in the 2 prong outlet, the Protection OK and DC Trigger lights came on, but no ground.


In the kitchen and other living room, there are 3-prong outlets, and so I then went around the house and plugged the power conditioner into each 3-prong outlet and turned it on to see if the Ground OK light came on, but for each outlet I tried, only the Protection OK and DC Trigger lights came on. Does this mean that none of the outlets in the house(even the 3 prong ones) are grounded?

Those outlets are ungrounded or the lights are no longer working.

Quote:
Drew Eckhardt - What do you mean by case?

The metal case on the equipment.

Quote:
Is equipment failure pretty uncommon?

I don't know. It happens.

Quote:
By grounded person do you mean any person standing on the ground?

Your wood sub-floor is a good enough insulator.


Touching something connected to earth ground, where the most common things might be a sink or metal-cased video component.
 

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I suggest you call Zero Surge (800-996-6696) and say you are thinking of buying their surge protector and explain your wiring situation. They are some of the nicest and most knowledgable people around and will give you reliable information. You might even wind up buying their surge protectors, which are great products.

http://www.zerosurge.com/residential.cfm
 

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Is it possible to pull one of the outlets in question out and see what kind of wiring is installed? It is possible you have an armor jacketed (BX) type or a romex wire with the ground fastened to the box. If so, you may already be grounded at the outlet locations. Two-prong outlets may have been installed for a variety of reasons. Test for ground. If you have it, just install a three-prong outlet. You won't even have to wire to the ground screw on the three-prong if the above scenario aplies. The outlet will be grounded thru the metal tabs on the outlet. I would attach the ground wire to the ground screw though.
 
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