"Higgs Boson" wrote in message
...
On Aug 4, 6:14 pm, wrote:
On Wed, 4 Aug 2010 11:08:47 -0700 (PDT), wrote:
On Aug 4, 8:32 am, jamesgangnc wrote:
On Aug 4, 12:37 am, Higgs Boson wrote:

On Aug 2, 4:14 am, "RBM" wrote:

"Higgs Boson" wrote in message

...
On Aug 1, 10:11 am, jeff_wisnia
wrote:

Higgs Boson wrote:
Lately, one circuit on my box blows. It covers the microwave
and
regular oven. I could
understand it blowing when another heat-using appliance, like
toaster
oven or toaster runs at same time as microwave. But now it's
blowing
all on its own.

Last time, today, only the micro was being used, to "reduce" a
glass
dish of chicken drippings.

Can one circuit go bad all on its own? If so, why? And what
should I
do about it.

Any info appreciated.

Since nobody has mentioned this yet and it sounds like it's a
kitchen
circuit, is the breaker perchance a GFI one?

The microwave may have marginal "hot to ground" leakage which
sometimes
becomes high enough to trip a GFI breaker.

If it's not a GFI breaker, then I'll side with those who say,
"change
the breaker.

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...)

Jeff

--
Jeffry Wisnia
(W1BSV + Brass Rat '57 EE)
The speed of light is 1.8*10e12 furlongs per fortnight.

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?

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-
Hide quoted text -

- Show quoted text -

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.- Hide quoted
text -

- Show 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.

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.

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.