Non Grounded duplex poll. Which is safer?

[frankft2000]

A local city informed me that they do not recognize replacing a non grounded receptacle with GFCI protection. That got me thinking about safety.

 

[iwire]

In my opinion the circuit with the EGC is safer due to the fact GFCIs have much higher failure rates than EGCs.

 

[ptonsparky]

Probably the only time I agree with the majority of voters.

A three wire device will return fault current via the eg and under most conditions you will not be aware of it. A 2 wire with gfci will have to return fault current via you. You will most likely feel the current flow.

 

[Dennis Alwon]

I don't think this is a fair comparison. For me it would depend on what the circuit was feeding. If the receptacles where in a bedroom then I have no doubt 3 wire with egc is the way to go. If it were outside then a gfci would be better. Therefore I won't vote.

 

[George Stolz]

Notice the GFCI circuit has no EGC.

 

[Dennis Alwon]

Notice the GFCI circuit has no EGC.

If this post is for me I did see that but I still would rather have the gfci outdoors and only 2 wires.

 

[George Stolz]

If this post is for me I did see that but I still would rather have the gfci outdoors and only 2 wires.

Okay, I'll bite: Why?

 

[iwire]

Okay, I'll bite: Why?

Me too.

EGCs typically last as long as the circuit, GFCIs have a very poor history of longevity.

Beyond that in most cases (not all) a proper EGC will prevent a shock, GFCIs (in most cases) will not prevent a shock, they hopefully will prevent an electrocution.

I may go looking but I do not think OSHA allows the 'no EGC with GFCI' receptacles in the workplace because of the other hazards created when someone jerks away from a shock.

 

[readydave8]

In my opinion the circuit with the EGC is safer due to the fact GFCIs have much higher failure rates than EGCs.

I voted for GFCI because it should be safer, I did not consider failure rate of GFCI.

 

[growler]

I don't think this is a fair comparison. For me it would depend on what the circuit was feeding. If the receptacles where in a bedroom then I have no doubt 3 wire with egc is the way to go. If it were outside then a gfci would be better. Therefore I won't vote.

I was thinking the same thing Denis. Each would have an advantage in certain situations. If we are talking about a ragged out old extension cord and wet grass I'll go with the GFCI.

I aslo think we have to assume that both the GFCI and equipment ground are both installed correctly and are functioning at the time of test. I have seen a lot of circuits that are supposed to be grounded that are not.

 

[Dennis Alwon]

Okay, I'll bite: Why?

Sure the GFCI fails but generally they fail to work at all. I think if I am working outdoors I would rather have the protection a gfci since a standard circuit could leak voltage and not trip the breaker.

 

[jxofaltrds]

Only two of us for GFCIs.

 

[charlie b]

I voted for the 2-wire with GFCI. That makes three so far, Mike.

In my opinion the circuit with the EGC is safer due to the fact GFCIs have much higher failure rates than EGCs.

I did not take that into consideration, and will continue to not consider it. The question asked which "IS" safer, not which will retain its degree of safety (however much that is) for the longer period of time. When things fail, they should be repaired or replaced. In the mean time, if a person were to receive a shock (the primary safety issue that applies to this question), which would be more likely to protect the person from electrocution? I believe it is the GFCI that would do that.

Unless the victim's body is electrically isolated from planet earth and unless the victim managed to get his body in series with the ungrounded wire and the grounded wire (not an easy task, but certainly possible), the GFCI will terminate the event before any harm can come about. You cannot say that about a 3-wire circuit with no GFCI protection. It is not hard to postulate a shock that has sufficient current to be fatal, but not enough current to trip the circuit breaker.

 

[iwire]

I voted for the 2-wire with GFCI. That makes three so far, Mike. I did not take that into consideration, and will continue to not consider it.

Certainly your prerogative.

I will continue to consider the lifespan of the equipment.

The question asked which "IS" safer, not which will retain its degree of safety (however much that is) for the longer period of time.

I think you are putting to much weight into the particular wording of the question.

IMO the OP is not asking which is safer at the moment of installation.

When things fail, they should be repaired or replaced.

Yes and GFCIs should be tested each month.

I thought we were talking about which is safer in the real world, not just safer in text?

In the mean time, if a person were to receive a shock (the primary safety issue that applies to this question), which would be more likely to protect the person from electrocution? I believe it is the GFCI that would do that.

IMO There are far to many variables to say that IMO.

Lets think of a metal appliance with a grounded cord.

Plug that into an EGC protected branch circuit and there is a ground fault in the appliance the over current device will open. No one gets hurt.

Plug that same appliance with a ground fault into a two wire circuit with GFCI protection and the appliance will likely sit there with a hot case until a person gets between it and ground. At that point the person will receive a 120 volt shock for the duration of the time it takes to GFCI to open the circuit.

To me it is safer not to receive any shock than to receive even a GFCI protected shock.

If the poll had a third option, EGC with GFCI I would choose it.

 

[jxofaltrds]

 

[don_resqcapt19]

If the equipment being used has an EGC to it, then I would say that the 3 wire circuit would be safer, however in the cases of equipment with only 2 conductor cords, I see the GFCI as being safer. With a connected EGC, there should be no shock hazard. (the code sized EGC is intended to be larger enough that the voltage drop under fault conditions is 40 volts or less, the normal voltage considered to be a shock hazard is 50 volts or more) The GFCI does not eliminate the shock...it only limits the duration of the shock.

 

[jxofaltrds]

If the equipment being used has an EGC to it, then I would say that the 3 wire circuit would be safer, however in the cases of equipment with only 2 conductor cords, I see the GFCI as being safer. With a connected EGC, there should be no shock hazard. (the code sized EGC is intended to be larger enough that the voltage drop under fault conditions is 40 volts or less, the normal voltage considered to be a shock hazard is 50 volts or more) The GFCI does not eliminate the shock...it only limits the duration of the shock.

That reminded me of all the 2 prone devices out there. Lamps, phone chargers, etc.

 

[LarryFine]

Keeping in mind there are many variables these choices ignore, and thus we're stuck with two generalizations, I vote GFCI.

The reason is that the GFCI specifically reacts to shocking current, with or without an EGC, or even a grounded conductor.

 

[frankft2000]

Nice discussion here. I did not think a person whould get, or feel a shock of 120 volts if the GFCI was working properly. My line of thinking was that a proper working gfci would trip at .5 milliamps as to prevent death, where on this board I have read several times about circuit breakers not tripping, even with direct shorts, and I'm not talking just about fedaral pacific breakers.

 

[iwire]

The GFCI will start to react anytime the current imbalance gets above around 6ma. The time between that and when the GFCI opens you are getting full voltage and current limited only by your skins resistance.

The GFCI cannot limit current or voltage, all it can do is open the circuit.