One circuit often blows

[Joe]

Higgs the troll. Plonk.

Joe

[Higgs Boson]

Oops - I should have made it clear that only the instrument panel on the "regular oven" went out - IOW, the time of day and light bulb inside went out. This is a regular wall oven with two compartments. It doesn't pull anything to speak of.

The microwave oven is new - replaced only a few months ago.

I don't have AC. (live in a near-perfect climate!)

OK, based on what I've read on this thread, and from my vast well of ignorance, I think it may, in fact, be a bad breaker. Note that I reported that in the past, MW only went out when used same time as other HEAT using devices (toaster oven; toaster).

Tx for your analysis.

[Higgs Boson]

The breaker box was installed many years ago and I don't have any paper work on it. Is there a way for a non-techie to ascertain whether it is a GFI breaker?

Also, is it normal for a near-new MW to have the "marginal "hot to ground" leakage? How do I ascertain this?

(Starts to look like an expensive electrician visit...sob...)

[RBM]

The breaker box was installed many years ago and I don't have any paper work on it. Is there a way for a non-techie to ascertain whether it is a GFI breaker?

Also, is it normal for a near-new MW to have the "marginal "hot to ground" leakage? How do I ascertain this?

(Starts to look like an expensive electrician visit...sob...)

From your two replies, it sounds like this circuit is not dedicated to the microwave. Is it a 15 or 20 amp circuit? What is the wattage of the microwave? If there is truly nothing else operating simultaneously on the circuit, and it trips, it's most likely a problem with the microwave, or a bad breaker. Have you checked to see if anything else goes out when that circuit trips, such as the refrigerator or something in another room?

[jamesgangnc]

de quoted text -

I'm inclined to think he has a gas oven and the circuit supplies the microwave as well as 115 for the oven light/timer/whatever. At the price, replacing the breaker is the simplest test he can perform.

[RBM]

I'm inclined to think he has a gas oven and the circuit supplies the microwave as well as 115 for the oven light/timer/whatever. At the price, replacing the breaker is the simplest test he can perform.

I'm inclined to agree. It would certainly help to know the age of the house, which could help to determine how it may have been wired. If it's a fairly new house, the circuits for kitchen counter outlets can be shared with a gas stove outlet, a refrigerator outlet, and the dining room outlets. This makes it possible that something else may be running at the same time as the microwave. If it's an old house with no particular code to the wiring, it may be a 15 amp circuit, shared with anything, anywhere in the house.

[clare]

A breaker will only trip from overload so many times before it starts to malfunction (usually false trip), so if you've been kicking it by plugging in the toaster and the MW at the same time, that is likely what has happened. I'm assuming your "regular" oven is gas-fired???

[clare]

You can be almost guaranteed you do NOT have a GFI breaker installed in the panel. If you did, you would know because it has a test button (generally, anyways)

[HeyBub]

Simpler would be to swap wires in the breaker box and see if the problem moves.

[mkirsch1]

Wow. Um. Just wow. Do apples fall UP in your world?

James Watt and Georg Ohm are rolling over in their graves.

The power company doesn't reduce the voltage. The excessive strain put on the power grid is what causes the voltage to drop...

Amps don't increase when voltage drops, either. On simple resistive appliances, lower voltage causes lower Amps.

[Ralph Mowery]

This thread is full of misinformation. The power grid has reduced the voltage during periods of high demand. At the same time the frequency is slightly reduced from exactly 60 Hz. When the demand is reduced, the frequency is slightly above 60 Hz so the over all frequency will average 60 Hz over the long period of time. At this time the voltage will be slightly higher as the voltage is determined partly by the speed of the generators.

The power grid can not increase the amps. That is determined by the load of the grid. If the voltage is reduced, the current usually goes down for many devices.

[Higgs Boson]

The microwave is only a few months old, as I mentioned earlier. It is a Sears Kenmore Elite. Here are the specs:

Power Supply: 120 V AC, 60 Hz Rated Power Consumption: 1,600 W Microwave Output: 1,200 W Rated Current: 14.0 A

You are correct; the circuit is not dedicated to the microwave. As another poster mentioned, older houses don't always have dedicated MW circuits.

How do I find out whether it is a 15 or 20 amp circuit? Is this relevant if, as it appears, I will have to have a dedicated MW circuit installed?

******QUESTION: What should such an electrician visit cost, including parts. This is a fairly expensive area, and I am not a fairly expensive homeowner, so I need to budget ahead. Estimates appreciated.

In answer to your q. if anything else goes out when the circuit trips: No, just the light panel on the wall oven and the toaster and/or toaster oven IF either happens to be on and pulling juice. Nothing in another room.

Your advice much appreciated.

As another poster mentioned, older houses don't always have dedic

[Higgs Boson]

.

In answer to the above messages, yes, it is a gas oven.

The house is pretty old; 40's, I think. However, I did have electrical work done several decades ago -- can't remember exactly when or what (sob) -- and a modern breaker box installed. There are 11 breakers serving different parts of the house and garden. Things are up to code.

[jamesgangnc]

.

By reading the breaker handle. If it is a 15amp circuit then it would be helpful to know how much of the rest of the kitchen is on it. That microwave is going to pull around 12 to 13 amps based on it's 1600 watt label. If you are on a 15amp circuit and the fridge is also on it then your problem is probably that the fridge tries to start up while the microwave is running. I'm also inclined to guess you had a less powerfull microwave before. You can not use other stuff in the kitchen while microwaving but you can't really easily control when the fridge will try to kick in.

Upgrading the circuit to 20 amp is not very practical. Running a new dedicated circuit for the microwave would be your simplest solution. How much that costs depends on a lot of variables like distance from the breaker panel and how difficult it will be to run the wire. Where you are factors in as well, some locations are only going to allow a licensed electrician or the homeowner to perform this work. In that case an economical alternative solution is to get a more knowledgable friend to help you diy it. You'd be better off getting some local quotes as far as possible prices go than asking here.

[hallerb]

Wierdly I am having the exact same issue, a microwave tripping breaker. Its done it a few times now.......

Yesterday it tripped again and wouldnt reset. So its time for a new breaker.

The microwave on another circuit is working fine

[trader4]

...

quoted text -

Agree with the above. The MW is rated at 14 amps, 1600 watts. If it's on a 15 amp breaker, that doesn't leave much for any other load. Which is why with new wiring there is a dedicated circuit for the microwave. Another possible alternative that would be a lot less expensive is finding a MW that is lower power.

But first he needs to determine:

Is it a 15 amp breaker/circuit? What else is on that circuit. Can he easily avoid any additional load on the MW circuit by moving any other loads to a different circuit, eg plug the toaster into a different outlet.

[clare]

He has answered the second half or your question several times - the clock of the gas oven (which likely draws less than 200 Ma), and the toaster opr toaster oven if he has it plugged in - If he ONLY uses the Microwave, or ONLY uses the toaster, the 15 amp breaker should hold. The only thing to do is to replace the breaker and see what happens. A dedicated 20 amp split countertop receptacle should be installed in the kitchen replacing whatever he is plugging the toaster into, leaving the Microwave and gas oven on the existing circuit. This would give him 2 20 amp circuits to handle toasters, coffeemakers, toaster ovens, etc without danger of tripping breakers from inadvertent overloads - and would get him almost code compliant. (which adding a separate circuit for the microwave would not). The countertop receptacles should be on GFCI protected circuits whereas the microwave and oven are not so critical that way.

[Higgs Boson]

com...

ide quoted text -

OMG, now I am more anxious than ever. Why would "adding a separate circuit for the microwave" not get me code compliant? This is a civilian talking, who doesn't know from code.

Also, can you explain "split countertop receptacle"? What is the "split" about? I went on-line to get a definition, but never did find one as such. Found a number of sites, but all too technical for me. Whatever the job turns out to be, I will have to hire a qualified electrician; this is not a DIY, even with help.

Also: You say "The countertop receptacles should be on GFCI protected circuits whereas the microwave and oven are not so critical that way." Can you explain the reason?

Also: Someone in this thread suggested refrigerator cycling on might be causing the trips. I just checked by disabling the breaker governing MW and gas oven, and it does NOT govern the refrig.

Last: Would doing the "split countertop receptacle" obviate the necessity of replacing what might be a defective breaker controlling the MW and gas oven, leading to repeated trips?

TIA to all for your continued help! Much appreciated.

HB

[RBM]

OMG, now I am more anxious than ever. Why would "adding a separate circuit for the microwave" not get me code compliant? This is a civilian talking, who doesn't know from code.

Also, can you explain "split countertop receptacle"? What is the "split" about? I went on-line to get a definition, but never did find one as such. Found a number of sites, but all too technical for me. Whatever the job turns out to be, I will have to hire a qualified electrician; this is not a DIY, even with help.

Also: You say "The countertop receptacles should be on GFCI protected circuits whereas the microwave and oven are not so critical that way." Can you explain the reason?

Also: Someone in this thread suggested refrigerator cycling on might be causing the trips. I just checked by disabling the breaker governing MW and gas oven, and it does NOT govern the refrig.

Last: Would doing the "split countertop receptacle" obviate the necessity of replacing what might be a defective breaker controlling the MW and gas oven, leading to repeated trips?

TIA to all for your continued help! Much appreciated.

HB

A split receptacle is what they do in kitchens in Canada. It's two circuits to one outlet. It's not typically done in the U.S. In the U.S. all kitchen counter top outlets are supposed to be GFCI protected, regardless of what they're used for. All you really need to do to remedy your problem, is run a dedicated 20 amp circuit and outlet for this microwave.

[mike]

Can't you just measure the load? Count how long it takes the wheel on the power meter to go around. Turn on the suspect appliance. Count the wheel again. Calculate the load difference.