My New House & Workshop

[RonD]

I've done a lot of work inside my house. Unfortunately one of the problems I keep having is with my microwave. It's a new microwave and it will occasionally trip the breaker when I turn it on. It's a new microwave by itself on a new GFCI outlet on a new breaker box with a 20 amp breaker. I have no idea why it occasionally trips the breaker.

If the GFCI outlet is not "tripping" then I would swap the breaker around to see if its a breaker fault
Also when breaker is off see what other outlets are also off

Microwaves draw from 10-15 amps on start up

"occasionally trip breaker" can mean another device that draws power "occasionally" is sharing that breaker, and if its on, and microwave comes on breaker trips
Refrigerator/Freezers cycle on and off randomly for example

 

[Jim Oaks]

The microwave is on a circuit by itself. The breaker kicks off sometimes when I press the '1' button to warm something for 1-minute. I kicks as soon as I press the button.

 

[franklin2]

I suspect the breaker or a problem with the microwave itself.

 

[RonD]

+1^^^

Get an extension cord or move microwave to another outlet, and see if it trips that breaker when you "press the '1' button to warm something"
If so its the microwave, if not its the breaker

It may be a bad breaker or a 10amp breaker with a 20amp label, lol

 

[Jim Oaks]

It's weirdly random when it happens.

 

[pjtoledo]

my microwave doesn't have different power levels, it varies on and off time to accomplish the (average) power level selected.
that way it turns on several times during heating.
does your's work that way? could account for the seemingly random tripping.

 

[Eddo Rogue]

Pretty sure it's the gfi. I'd put in a higher amp or just bypass it, as in put a regular outlet there. I've had problems with both GFI's and breakers.

 

[1990RangerinSK]

Pretty sure it's the gfi. I'd put in a higher amp or just bypass it, as in put a regular outlet there. I've had problems with both GFI's and breakers.

Does code allow a non-GFI in the kitchen? I know Jim said early on that there are no inspections where he lives, but code still applies. So, if electrical code says that in the kitchen the plugin has to be a GFI, then it has to be a GFI.

 

[Roert42]

Pretty sure it's the gfi. I'd put in a higher amp or just bypass it, as in put a regular outlet there. I've had problems with both GFI's and breakers.

A GFCI receptacle has 0% relation to the amps draw of a circuit. If the breaker in the panel is tripping then it is related to amps draw.

 

[Jazzer]

You can’t put a higher amp breaker in unless the wire size is adequate for that amperage. The cable would become a heat strip.

GFCI’s for all kitchen countertops within 6’ of water.

Post #1024 is the concise explanation.

Also, tighten connections at breaker and receptacle. If the receptacle is “backwired” (push in connectors used), move the wires to the screw terminals.

-Jazzer

 

[bobbywalter]

You can’t put a higher amp breaker in unless the wire size is adequate for that amperage. The cable would become a heat strip.

GFCI’s for all kitchen countertops within 6’ of water.

Post #1024 is the concise explanation.

Also, tighten connections at breaker and receptacle. If the receptacle is “backwired” (push in connectors used), move the wires to the screw terminals.

-Jazzer

This. Especially with aluminum wire.

Check both sides. They come loose...and can cause fire as well

 

[Eddo Rogue]

Does code allow a non-GFI in the kitchen? I know Jim said early on that there are no inspections where he lives, but code still applies. So, if electrical code says that in the kitchen the plugin has to be a GFI, then it has to be a GFI.

No it does not. I had to obey code and wire in a 60 amp breaker within a certain distance and location of my hot tub. It always tripped. I asked my electrician about it. He said they're never reliable, the fix is to bypass it after inspection.

My HVAC guy once had a beautiful metal frame built to mount a rooftop AC unit. The inspector failed it due to no proof it was made by a certified welder. He asked the inspector how to get around that, and was told to build it out of wood. He made crappy wooden frame and passed inspection.

A GFI would trip instantly from a low demand flourescent light fixture. I think the ballast startup draw was what caused it.

 

[franklin2]

No it does not. I had to obey code and wire in a 60 amp breaker within a certain distance and location of my hot tub. It always tripped. I asked my electrician about it. He said they're never reliable, the fix is to bypass it after inspection.

My HVAC guy once had a beautiful metal frame built to mount a rooftop AC unit. The inspector failed it due to no proof it was made by a certified welder. He asked the inspector how to get around that, and was told to build it out of wood. He made crappy wooden frame and passed inspection.

A GFI would trip instantly from a low demand flourescent light fixture. I think the ballast startup draw was what caused it.

A GFI receptacle or the GFI section of a GFI breaker does not trip from load. It does not care what the load is. All it cares about is the balance of current from the black wire to the white wire.

In any electrical circuit, the current is the same in the whole circuit. This includes the hot wire going in, and the neutral going out (if you want to think of it that way, really it's A/C with no polarity). The GFCI receptacle monitors the current on the black wire, and the current on the white wire. When there is a slight difference (I forget the spec) the recept trips. This is the reason a GFI breaker has it's own white wire connection and a pigtail white wire made into it. It must have it's circuit's white wire to monitor.

If you get hung up on the black wire and start getting shocked, on a GFI circuit part of the current is going through you to ground. This throws the balance off, the white wire current is now lower, and it trips the GFI. If you have a piece of equipment or a ballast as the example above, and the insulation is not that great somewhere and you get a small leakage to ground, it's not enough to trip the main breaker, but it can be enough to throw the balance of the circuit off and cause the GFI to trip.

 

[RonD]

I would agree with franklin2 on this

GFI outlets are rated at say 15 amps because of the size of internal wiring/contacts not because they act as a circuit breaker, same as regular outlets are rated at 15 or 20amps

AC voltage works by cycling voltage from + to - , at say 60 times a second, this moves the electrons back and forth creating usable power for a device
DC voltage just moves the electrons in one direction
Not super accurate description, but good enough for this

GFI works, trips, if more electrons are moving on one wire vs the other, which can only happen when there is an imbalance in the load, electrons flowing out but not on the monitored wires, a leak in the system, lol

Higher flow back and forth but equal, high amp draw, shouldn't cause GFI to trip, but should cause circuit breaker to heat up and trip

A poor connection on GFI or at breaker panel, or if there is a splice in a Junction box, these could cause higher amp draw, and trip breaker

 

[Roert42]

When there is a slight difference (I forget the spec) the recept trips.

I think for normal GFCI it’s should be around 5 milliamps.