GFI tripping with new microwave-electricians?

[muscmp]

we bought a new more powerful microwave,1200 watts. every time it is used, it trips the gfi. everywhere that i've moved it that is convenient is also connected to the gfi and trips it. i've moved it to a very inconvenient place and it doesn't trip the gfi, however, it is plugged into the same outlet as the refrigerator and i'm not sure that is wise.

the house was built in 1978 so i don't know if a newer gfi would be less trippy or even a smart move. at least it doesn't trip anymore but it is sitting on a counter top at an angle for easier access and venting.

any recommendations, or do i give up since it is working ok now?
thanks,

mikeB

play music!

[Song]

What are you calling a gfi? The GFIs that are built into the receptacles, or at the circuit breaker box?

[Long Jon]

I thought it meant "girlfriend"

[buddyhu]

I used to trip the gfi....but that was way back in the 70's. I have responsibilities now.

[muscmp]

Originally Posted by Song

What are you calling a gfi? The GFIs that are built into the receptacles, or at the circuit breaker box?

song: circuit breaker box.
thanks,

[BrunoBlack]

On GFCI-protected circuits, leakage current can cause tripping. When many pieces of equipment are operating on a circuit, the leakage current is cumulative. Adding more equipment to a GFCI-protected circuit can trip a GFCI randomly, making the problem difficult to diagnose. It could be insulation on the wires, a faulty breaker, dust accumulation, etc. You should get an electrician in to diagnose.

[muscmp]

Originally Posted by Haasome

On GFCI-protected circuits, leakage current can cause tripping. When many pieces of equipment are operating on a circuit, the leakage current is cumulative. Adding more equipment to a GFCI-protected circuit can trip a GFCI randomly, making the problem difficult to diagnose. It could be insulation on the wires, a faulty breaker, dust accumulation, etc. You should get an electrician in to diagnose.

thanks, appreciate it. would it be worth my replacing the old gfi? i have replaced breakers before.

i guess it was the difference in the wattage that sent it over the top. thanks again,

[Gitfiddlemann]

we bought a new more powerful microwave,1200 watts. every time it is used, it trips the gfi. everywhere that i've moved it that is convenient is also connected to the gfi and trips it. i've moved it to a very inconvenient place and it doesn't trip the gfi, however, it is plugged into the same outlet as the refrigerator and i'm not sure that is wise.

Normally, GFCIs installed in kitchens (in homes of that age) come in the form of receptacles (outlets) which service counter top surfaces. The breaker(s) in the box protecting the circuits is (are) standard. (In newer homes, the rules have changed with the advent of AFCIs).
In your house, you are saying that there is a "kitchen" GFCI breaker in the panel box, and it is supplying/protecting a number of standard receptacles. Correct?
That's not necessarily wrong, but if that one GFCI device is protecting more than one receptacle, and/or a number of other loads, the additional loading from the oven on it could be causing it to trip. (At full power, the 1200W unit draws about 10 amps, and there are inrush currents to consider once they kick on). As mentioned, the GFCI breaker has the additional duty of protecting against ground faults, so they are more sensitive by nature. (How old is the breaker?)
Question:
What else is plugged in when you're trying out the oven?
You might try unplugging everything in those "convenient" outlets that the GFCI is protecting, and then trying the oven on its own. If it doesn't trip, then you know there is circuit overloading going on when the oven gets put into the mix.
That's probably what I would try first.
I also wouldn't connect both the oven and the fridge on the same circuit.
I have a 1200 oven too, and I keep both fridge and ovens on separate circuits.

[gjd100]

Originally Posted by muscmp

thanks, appreciate it. would it be worth my replacing the old gfi? i have replaced breakers before.

i guess it was the difference in the wattage that sent it over the top. thanks again,

Not sure if it is wise to have the fridge on the same circuit as the gfi receptacle ( i am not an electrician). My fridge is on its own circuit, as are the recepticles that ring the kitchen countertop: they are on their own gfi cifcuit. Unplug the fridge. Does the microwave still pop the circuit. If yes, probably the gfi breaker at fault. If no, then you are probably overloading the circuit.

[jhmulkey]

Originally Posted by Long Jon

I thought it meant "girlfriend"

Actually, for a player like you, Jon the last letter is a Roman numeral. Girlfriend I.

[Riverwolf]

I have a long detailed history installing and troubleshooting with 120/240 volt wiring.
I have replaced many GFCI breakers.
The breakerbox type are much more "rugged" and less prone to wearing out.
All breakers work as an on/off switch and every revolution will ever so slightly cause wear on the breaker.
For this reason and others, a breaker should not be used as a switch.
You are most likely tripping the box breaker due to current overload and not a ground fault situation.
In other words the breaker is probably just doing it's job.

[muscmp]

Originally Posted by Riverwolf

I have a long detailed history installing and troubleshooting with 120/240 volt wiring.
I have replaced many GFCI breakers.
The breakerbox type are much more "rugged" and less prone to wearing out.
All breakers work as an on/off switch and every revolution will ever so slightly cause wear on the breaker.
For this reason and others, a breaker should not be used as a switch.
You are most likely tripping the box breaker due to current overload and not a ground fault situation.
In other words the breaker is probably just doing it's job.

i never had a problem with the old microwave, so, if it is doing its job, i just have to go turn it back on when it trips?

i'll have to unplug other things to see how it reacts as andre mentioned above.

basic question: how do i know what is actually on the gfi circuit? i would think just bathroom and kitchen stuff near water??

thanks to all so far

[AX17609]

I just did a kitchen, and all I know is that modern electrical code dictates that microwave ovens have to be on their own circuit. They must have some kind of monster energy sucking potential.

[muscmp]

Originally Posted by AX17609

I just did a kitchen, and all I know is that modern electrical code dictates that microwave ovens have to be on their own circuit. They must have some kind of monster energy sucking potential.

i have open slots in the breaker box. how do i ensure the microwave gets its own circuit breaker. i see that the dishwasher and disposal have their own.

[Gitfiddlemann]

basic question: how do i know what is actually on the gfi circuit? i would think just bathroom and kitchen stuff near water??

GFCI breakers in panel boxes are usually there for dedicated purposes, i.e. to insure complete coverage in a room, such as a bathroom or laundry room. Sometimes, just the pump for a hot tub needs its own GFCI breaker.
In kitchens, they are commonly found as receptacles for counter tops or anything near a sink.
It wouldn't be usual to have a GFCI breaker service various receptacles or circuits in multiple rooms. That's unusual.
In your case, is there just one GFCI breaker? If so, it's possible that there are just too many loads on that one circuit. That's what I was thinking also, i.e. that the problem may just be an overloaded circuit and have nothing to do with its GFCI capability. The oven is simply adding too much "load" and the glass is overflowing. At 1200W, it's a power draw.
At the very least, you should know which breaker is protecting which circuit in the house. If you don't know, then the best way is to troubleshoot it. Process of elimination works, is easy to do, but it’s time consuming.
It’s worth it though.
Once you’ve identified all the circuits under that one GFCI, you’ll have a much better idea of how to proceed. And if an electrician should be called in.

all I know is that modern electrical code dictates that microwave ovens have to be on their own circuit.

Not to my knowledge. There is nothing in the NEC that specifically mandates that, unless it's a special local requirement. Which is possible.
It certainly makes sense though. I did the same for our oven.

i have open slots in the breaker box. how do i ensure the microwave gets its own circuit breaker. i see that the dishwasher and disposal have their own.

Dishwasher and disposal on their own circuit: Check!
Ideally, you could use one of those open slots for an additional breaker. A normal panel breaker. And have a dedicated GFCI receptacle into which the oven gets plugged in. (That would be meet the Code's requirements for counter top receptacles in kitchens).
The bad news is, running new wires in an existing home from the breaker panel to install the new equipment. Also making new holes in walls. Are you OK with that?
Installing the new breaker alone is dangerous, unless you know what you're doing.
It might be time to consult an electrician, at least before embarking on that road. There might be better alternatives available to you which are hard for us to consider based on this limited guitar forum information exchange.
But as a first step, do try to identify all the circuits under that one GFCI breaker of yours. That's definitely worth knowing! Check upstairs and downstairs too. Who knows where they are all at? (My house is over 100 years old, and I have some horror stories about what I uncovered....)