Home electrical: disposal wiring problem

So, here's the problem...
(note: I'm new to this house)When I flip the switch for the disposal it trips the gfci outlet that the switch runs off of. I just put a new switch in, and I've tested the outlet that the disposal plugs into. The disposal works if I plug it into the top outlet (always hot; where the dishwasher plugs into). Also, the switch doesn't trip the gfci outlet if the disposal is unplugged. I'm fairly certain that the wires are in the correct spots on the switch and dishwasher/disposal outlet. Not sure about the gfci outlet, but the microwave works off of it. I'm so confused.
Any help is much appreciated!

 

Am I understanding this correctly? Thinking the GFCI may be bad or wrong.

On a single gang box your bottom outlet causes the gfci to trip when the disposal is plugged into it and turned on.

 

Does the switch trip the GFI if something other than the disposal is plugged in?

 

Fridges, dishwashers, and disposals usually aren't put on GFI's because they cause nuisance tripping

 

I'm an appliance repair tech. In general, if you call any appliance manufacturer and ask them why your GFCI is tripping, they will tell you to take the appliance off the GFCI. The reason is that most electric motors have a certain amount of current leakage to ground. A regular resistance meter will not be able to detect any continuity to ground, but there is still some very small amount. The GFCI is designed to detect current leakage and will trip.

Now, there are plenty of refrigerators, washing machines, dryers, etc that are wired to GFCI outlets and they work fine. Often they work fine for years, then start to trip. In most of those cases, a new GFCI outlet or breaker will make the problem go away. Sometimes not. I believe the reason for that is that motors will leak more current to ground as they age.

Not sure what the electrical code says about it, but what I recommend to people is that the counter top outlets should be GFCI, so that when someone drops the blender or toaster into the sink, the protection is there. The outlet under the sink for the disposal and dishwasher, and the one behind the fridge should just be normal grounded outlets.

Maybe someone could speak up about what the national electric code says about this. I personally would get that GFCI off the under sink outlet, make sure the outlet is grounded, the disposal is grounded, and call it good.

 

Also, the top and bottom halves of that outlet (switched, not switched) are likely wired to a seperate breaker, and most likely not both wired to the GFCI. You can get a GFCI tester that plugs into the outlet and gives you a way to test that. Or you can use the test button on the GFCI outlet and see if the dishwasher quits when you trip it manually.

 

NEC says that only outlets feeding countertop surfaces in a kitchen need to be GFCI protected.

 

What is that?

Yes

So, maybe the hot wire coming out of the gfci outlet is messed up? The outlet itself is working. Could I bypass the gfci outlet and run the hot wire straight to the switch to see if that's the problem or is that a bad idea? Worst case it trips the breaker right?

 

Does the GFCI trip when you turn the switch on with nothing plugged in?

 

Don't just go shuffling wires around tripping breakers and what not. Breakers are only designed to trip so many times before they should be replaced. Don't go causing it to trip now because it may end up not tripping when you really need it to

 

Sorry, I wasn't clear about this. The gfci outlet is between the switch and the breaker. The undersink outlet is just a regular outlet. Also the whole left of my kitchen is on one breaker. Its a small house.

 

No

 

Then it likely is not the switch. Does it trip with any item you plug into that under sink outlet?

 

you could just move the wires on the load side of the gfi to the line side of the gfi. the disposal wouldn't be gfi protected, but it doesn't need to be.

 

That wouldn't fix the cause of the problem

 

Yes

Btw thanks for all the help guys! I love Tacoma World!

 

it would prevent nuisance tripping.

 

Have you taken the under sink receptacle out of the box and checked the connections? Might be a loose neutral on the switched one.

Make sure you turn off the circuit first

 

He established that it isn't nuisance tripping though because it trips with anything that is plugged into it

 

sorry, missed that.