GFCI plug to bathroom fan keeps tripping

Question

I am wiring 2 GFCI receptacles and a fan in a bathroom. Power goes to the 2 GFCI receptacles to line connections and both work fine. Then I connected a switch and fan to the load connections of one of the GFCI plugs and it just trips immediately. I have checked various sites and discussions and it looks right. What am I missing?

Answer 1

On a regular outlet, the 2 screws on each side are there merely for the convenience of splicing in the wires which go "onward" to the next outlet. Use of them is not a requirement, you can always pigtail - and they are not "Line" and "Load" because they are not GFCI protected. When novices install GFCIs, they get confused, and think the "onward" wires should always go on "Load", those being the other pair of screws available. It doesn't help that the instructions suggest (not require) to do that.

No, not at all. All screws on a GFCI support 2 wires by slotting them into channels under the screw and torquing the screw to spec. Or you can pigtail.

"Line" is the unprotected side of the GFCI. The GFCI receptacle is able to protect downline outlets and loads - they are protected same as the socket. That is the SINGULAR purpose of the "Load" terminals. This should never be done except in cases where you actively want to do that for a reason, like saving money on GFCIs by only having one of them protect the rest of the circuit, or GFCI-protecting a light or fan in a shower stall per Code.

To use the "Load" terminals, the onward wires - both hot and neutral - must be placed on the "Load" terminals.

And that's where people get in trouble with switches. Hot and neutral go to different places - hot goes to the switch but neutral goes straight to the lamp. So the usual situation is that the lamp neutral is left in the neutral bundle, which is the Line side of the GFCI, and the lamp hot is placed on the GFCI in the only obvious screw, "Load" hot, merely for splicing, but people don't know any better,

So the GFCI sees the lamp's hot current but it does not see the lamp's neutral current, it detects the current imbalance and trips. The cure is to find the lamp's neutral and pull it out of the neutral bundle and put it on GFCI Load.

Or, if the light does not need GFCI protection, attach lamp "hot" (which goes to the switch) to the GFCI "Line" terminal using the back-wire method, or pigtail hots.

Answer 2

Fans are inductive loads, causing dv/dt voltage spikes that can trigger a GFCI. Here are some ways of dealing with the issue.

• If the exhaust fan is ceiling mounted, in a grounded box, it might not require being on GFCI, so wire it before the GFCI outlet. Check local codes.
• A snubber circuit can be added across the fan to bypass the voltage spike.
• There are different classes of GFCI. For specific issues, such as using a commercial refrigerator with a GFCI, codes might allow a higher fault current (Class C) device to be used. However, that is *not suggested for a residential bathroom.