Regardless, if the GFCI is not grounded, you also needs a "No Equipment Ground" label both on the GFCI and any downline receptacles. (you don't need to label a GFCI receptacle that, because it's obvious). In that case, you must label the downline receptacles "GFCI Protected". If you do, then you remove the warning tape and use the "Load" terminals. If you don't want to protect a downline, you use only the "Line" terminals - and they are designed to accept 2 wires (check the instructions). So in fact, you can have full circuit GFCI protection without a single GFCI receptacle being involved.Īnyway, GFCI receps give you the choice whether to protect the downline or not. (GFCI receptacles protect their own sockets, obviously). Any GFCI device can protect a downline part of a circuit. GFCI is not a receptacle, it's a protection system. But that is highly improbable with good equipment design. Note that GFCIs do nothing about a human getting between hot and neutral. No one will ever know there was a problem. grounded power strip) - will cheerfully float at 120V from neutral, like a bird on a wire. If the human touches hot and ground and the ground is isolated, then all of it - hot, human, chassis ground, and any grounds in that "island" (i.e. If a human touches hot and ground and the system is grounded, current will flow and the GFCI will trip. Lack of ground, however, reduces the chance of a shock happening (and thus a shock being detected). That is better human protection than grounding, actually. The ruling factor for safety is that the GFCI will shut off if more than 5ma leaks (e.g. In terms of safety, GFCI is all you need. That being said, using it in place of retrofitting ground is often practical and cost-effective protection. Since the extra protection provided by GFCI is most useful in wet areas, GFCI protection is required in kitchen, bath, outdoor (rain) and certain other locations, but not "everywhere". GFCI also can have some drawbacks (an unnoticed GFCI trip turning off a refrigerator can result in spoiled food). GFCIs are not free, so there is a cost-benefit analysis involved. Note also that "better protection" does not, generally speaking, mean that "everyone should put GFCI everywhere". In particular, a short circuit where all current goes back on neutral (and nothing on ground or through a person) will have no effect on a GFCI because the GFCI still sees the hot & neutral as balanced. Note that a GFCI does not substitute for the regular breaker in every aspect. The end result is that a GFCI can effectively substitute for a ground wire, since the same faults that would normally use ground will instantly trip a GFCI, and additional safety because it trips on small amounts of current and very quickly. It activates extremely quickly (a regular breaker will trip very quickly if it gets a huge overload but not so quickly for a small overload (e.g., 30A on a 20A circuit).Ī GFCI also doesn't really "care" whether the current is going to an actual ground wire (and directly back to the breaker panel) or if it is going through a person to the ground under their feet.It activates on tiny amounts of current (not enough to kill, but far less than it would take to trip a breaker).The second case - actual faults in wiring or equipment - is designed in a way that if lots of power goes over ground, the breaker (which is on the hot wire) will trip, shutting off the circuit.Ī GFCI takes this "fault" a few steps further. Fault - device failure that sends power either directly to ground or via a metal case (or other metal parts) to ground.Natural - lightning, static electricity, etc.switches with no neutral available - not ordinary receptacles). The traditional ground wire has no power flowing over it in normal usage, with the exception of some special types of switches or other equipment that are allowed to send a very small amount of current over ground (this generally has to do with smart/dimmer/timer/etc. You are supposed to label them no equipment ground. When you install GFCI in this way, you do everything the same as a regular installation except that you don't connect anything to the ground screw. But it means that if you don't have ground, GFCI can protect you anyway. That doesn't mean you shouldn't have ground. In fact, a properly installed GFCI will provide protection similar to (and actually in some ways better than) a regular ground. A GFCI, despite the "G", does not actually need a ground wire to function. There are a number of different functions that an ordinary ground wire performs.
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