Self-Clean Range Will Not Work

[wei]

We have a ten-year old GE self-cleaning glass-top electric range.
My wife had never used the self-cleaning feature mainly because of the
high electricity consumption (she says).

Anyway, because she is now disabled, leaving me to become chief cook
and bottle-washer, I find that I now need to clean the oven. I
decided I would try the self-cleaning feature to ease my tasks a
little.

Imagine my surprise when I discovered that the cleaning cycle would
only run some 10 minutes before tripping the 220 breaker. When I
reset the breaker, and tried it again, it did the same. Three times
before I quit, fearing that there must be an overload. The breaker is
a 40-amp'er.

I can and did clean the oven manually, with easy-off, and can continue
to do so. But I am wondering why this all happened.

What does everyone think?

xiexie

Wei

 

[wei]

Sorry

Wei

 

[philo]

We have a ten-year old GE self-cleaning glass-top electric range.
My wife had never used the self-cleaning feature mainly because of the
high electricity consumption (she says).

Anyway, because she is now disabled, leaving me to become chief cook
and bottle-washer, I find that I now need to clean the oven. I
decided I would try the self-cleaning feature to ease my tasks a
little.

Imagine my surprise when I discovered that the cleaning cycle would
only run some 10 minutes before tripping the 220 breaker. When I
reset the breaker, and tried it again, it did the same. Three times
before I quit, fearing that there must be an overload. The breaker is
a 40-amp'er.

I can and did clean the oven manually, with easy-off, and can continue
to do so. But I am wondering why this all happened.

What does everyone think?

xiexie

Wei

Check the nameplate of the oven...good chance it needs to be on a 50 amp
circuit.

BTW: Due to the huge power consumption I'd just clean it the old
fashioned way. If you get it nice and clean and are careful with you
cooking...you can get by without cleaning it.

Our over is 12 years old and has never been cleaned...
it's not spotless, but it's not too bad either

 

[Paul]

Check the nameplate of the oven...good chance it needs to be on a 50 amp
circuit.

BTW: Due to the huge power consumption I'd just clean it the old
fashioned way. If you get it nice and clean and are careful with you
cooking...you can get by without cleaning it.

Our over is 12 years old and has never been cleaned...
it's not spotless, but it's not too bad either

An electrician can use instruments such as a clamp-on AC ammeter,
to measure the actual load. That would help distinguish, between
an overload inside the stove, versus a weak breaker.

The breaker could be weak. Some screws around the breaker, could be
loose and not securing the wires properly inside the panel. (That
results in local heating inside your electrical panel.) An electrician
can inspect the panel, and put it right for you.

Thermal expansion, is the enemy of electrical things. Heat causes
fuses to unscrew, screws that screw the wire to the panel to unscrew,
causes electrical connections to become ohmic and create even more heat.
Which is why an inspection is a good idea if fuses or breakers are tripping.
And if you actually had a problem of that type, you'd want to regularly
re-check the item, because it will only repeat the problem at a future date.

If there was a fault in the stove itself, there likely would
have been "smoke" by now.

Paul

 

[wei]

Check the nameplate of the oven...good chance it needs to be on a 50 amp
circuit.

BTW: Due to the huge power consumption I'd just clean it the old
fashioned way. If you get it nice and clean and are careful with you
cooking...you can get by without cleaning it.

You sound like my wife.

Our over is 12 years old and has never been cleaned...
it's not spotless, but it's not too bad either

Cleaning every few years is not all much of a pain either.

Another thing that is bothering me is that when I was cleaning the
oven yesterday with the easy-off, I laid a wet rag on top of the oven
element (oven switch was off of course) which was cold and it popped
(a short) tripping the breaker too. Scared me. Really, when you
think about it, there should not have been any juice in the element.
So something must be wrong. I tested the oven just now, and all seems
okay as far as heating is concerned.

xiexie

Wei

 

[philo]

Another thing that is bothering me is that when I was cleaning the
oven yesterday with the easy-off, I laid a wet rag on top of the oven
element (oven switch was off of course) which was cold and it popped
(a short) tripping the breaker too.

That's all the info I needed to hear, there is a *definite* problem and
you need to get it fixed at once or someone may get electrocuted.

Since you are not familiar with troubleshooting
you need to hire someone to check the range and your circuit!

Serious stuff here!

 

[wei]

That's all the info I needed to hear, there is a *definite* problem and
you need to get it fixed at once or someone may get electrocuted.

Since you are not familiar with troubleshooting
you need to hire someone to check the range and your circuit!

Serious stuff here!

I agree for sure. Monday is a workday unlike today. I plan to put a
test meter on the element to see what I see. Then I will remove the
circuit breaker box cover so I can look at the breaker as well as
check the tightness of the breaker's screws and the condition of the
wire contacts involved. I know how to do that, and know how to change
a breaker, but I might still bring in an electrician just to be sure
all is okay. As I said, my wife is disabled, with dementia, and I
don't have the time any more to handle things like this, and certainly
need to worry about how this could affect her.

We cooked a meal tonight in the oven, and it went okay.

xiexie

Wei

 

[wei]

That's all the info I needed to hear, there is a *definite* problem and
you need to get it fixed at once or someone may get electrocuted.

Since you are not familiar with troubleshooting
you need to hire someone to check the range and your circuit!

Serious stuff here!

I agree for sure. Monday is a workday unlike today. I plan to put a
test meter on the element to see what I see. Then I will remove the
circuit breaker box cover so I can look at the breaker as well as
check the tightness of the breaker's screws and the condition of the
wire contacts involved. I know how to do that, and know how to change
a breaker, but I might still bring in an electrician just to be sure
all is okay. As I said, my wife is disabled, with dementia, and I
don't have the time any more to handle things like this, and certainly
need to worry about how this could affect her.

We cooked a meal tonight in the oven, and it went okay.

xiexie

Wei

 

[philo]

ook at the breaker as well as
check the tightness of the breaker's screws and the condition of the
wire contacts involved. I know how to do that, and know how to change
a breaker, but I might still bring in an electrician just to be sure
all is okay. As I said, my wife is disabled, with dementia, and I
don't have the time any more to handle things like this, and certainly
need to worry about how this could affect her.

We cooked a meal tonight in the oven, and it went okay.

xiexie

Wei

If putting a wet rag on an element caused the breaker to blow,
the problem is in the range itself

 

[Paul]

If putting a wet rag on an element caused the breaker to blow,
the problem is in the range itself

To trip on that kind of load, there'd almost have to be
a ground fault detector in the system somewhere. I doubt
you could push 15 or 20 amps through a wet rag, and pop
a regular breaker on current. But something like a GFCI,
is would make milliamps to trip one of those. Do they use
something like that now (as code) ? Would there be ground
fault detection in the range itself ? Sounds pretty weird.
A regular breaker shouldn't be that easy to trip.

http://en.wikipedia.org/wiki/Residual-current_device

Paul

 

[dpb]

On 5/7/2012 12:21 AM, Paul wrote:
....

To trip on that kind of load, there'd almost have to be
a ground fault detector in the system somewhere. I doubt
you could push 15 or 20 amps through a wet rag, and pop
a regular breaker on current. But something like a GFCI,
is would make milliamps to trip one of those. Do they use
something like that now (as code) ? Would there be ground
fault detection in the range itself ? Sounds pretty weird.
A regular breaker shouldn't be that easy to trip.

....

I'm thinking that (the rag) was coincidental to whatever actually caused
the breaker to trip unless there's a bare connection or somesuch that it
jarred to ground to the range body which is at ground...

--

 

[trader4]

On 5/7/2012 12:21 AM, Paul wrote:
...

Not in the USA NEC, that's for sure.


Not in any range I've ever heard of. It would just
be another expense, so why would they do it?
And even if there were, then that GFCI would be
tripping, not the panel breaker, which is what
happened.




Sounds pretty weird.

...

I'm thinking that (the rag) was coincidental to whatever actually caused
the breaker to trip unless there's a bare connection or somesuch that it
jarred to ground to the range body which is at ground...

--

Agree. The odd thing here is that a heating element with the oven
shut off would have power on it at all. I guess
it's possible they only switch one side of the 240V. In
that case, a short to ground would result in a 120V
path. If that is the scenario, then the wet rag could have
completed a short that was partial to begin with. As
could the extra high heat from the clean cycle.

 

[philo]

Not in the USA NEC, that's for sure.



Not in any range I've ever heard of. It would just
be another expense, so why would they do it?
And even if there were, then that GFCI would be
tripping, not the panel breaker, which is what
happened.




Sounds pretty weird.

Agree. The odd thing here is that a heating element with the oven
shut off would have power on it at all. I guess
it's possible they only switch one side of the 240V. In
that case, a short to ground would result in a 120V
path. If that is the scenario, then the wet rag could have
completed a short that was partial to begin with. As
could the extra high heat from the clean cycle.

Bottom line: the OP needs to get it fixed and by someone who knows what
they are doing. Even 115 volts can be fatal!

 

[trader4]

Even that shouldn't happen. The heating element is ceramic
with the heating wire running through the core, so it's surface
is totally insulated. Although it's connected across 240v, a
stove is basically a 120v device.

With 240V across the heating elements, a stove is
*not* a 120V device. If it is then so is a water heater,
a dryer and anything else that runs off 240V

The panel breaker assembly
has two 120v breakers, one to each 120v bus. All stove elements
are 120v, and wired so that in normal use the load is equalized
from each 120v bus to neutral.

I'll bet you I can find ovens where the heating elements
are 240V and connected directly across the 240V. And I would bet
that's most of them.

 

[krw]

With 240V across the heating elements, a stove is
*not* a 120V device. If it is then so is a water heater,
a dryer and anything else that runs off 240V

The clocks (and any electronics) are often run off 120V, though I think what
he means is that no point of the (NA) stove is more than 120V from ground.

I'll bet you I can find ovens where the heating elements
are 240V and connected directly across the 240V. And I would bet
that's most of them.

I don't think you're reading this the way he wrote it. Try the above
paragraph again. ;-)

 

[Paul]

I read it again and he's saying that the heating elements
in all ovens are 120V, not 240V and that they are
actually connected from one hot to neutral. I believe that
is not true, ie if you put a volt meter across most oven
elements you're going to read 240V.

In my experience, the oven uses "two hots", for a total of 230V across
the element.

The stove top elements are between hot and neutral, for 115V. And on the
stove I used to work on back home, the stove elements draw 750W or 1500W.
So they don't need more than 115V to do that, for the stove top.

The two hots would be 180 degrees out of phase, which is why the
"voltages add". If the "hot to neutral" is X, the "hot to hot" is 2X.
The term they use here is "legs" rather than "phases" (so as not
to confuse with 3-phase industrial power).

http://en.wikipedia.org/wiki/Split_phase

Paul

 

[trader4]

In my experience, the oven uses "two hots", for a total of 230V across
the element.

Exactly. Which makes the self-cleaning oven we're talking
about a 240V appliance.

The stove top elements are between hot and neutral, for 115V. And on the
stove I used to work on back home, the stove elements draw 750W or 1500W.
So they don't need more than 115V to do that, for the stove top.

I don't know about your stove, but I can show you wiring diagrams
for stoves that show the stovetop heating elements connected
across 240V. The ones I've dealt with have used 240V. They
only use 120V for lights, indicators, timer motors, etc. Since
240V is available, what exactly is the point to using only 120V?
You can get the same power with half the current, which is
always a good thing because you have less loss in the wiring.

The two hots would be 180 degrees out of phase, which is why the
"voltages add". If the "hot to neutral" is X, the "hot to hot" is 2X.
The term they use here is "legs" rather than "phases" (so as not
to confuse with 3-phase industrial power).

No disagreement there. The part I disagree with was the
claim from Ian that a stove is basicly a 120 volt device.
That's wrong and apparently you agree because you
say the oven elements are 240V. I know many of the
stove top elements are too. I'll even bet most of them are.
If you have a wiring diagram online that shows a stove
wired with 120V elements for the cooktop,
I'd be happy to see it.

 

[krw]

I read it again and he's saying that the heating elements
in all ovens are 120V, not 240V and that they are
actually connected from one hot to neutral. I believe that
is not true, ie if you put a volt meter across most oven
elements you're going to read 240V.

You're right, he was OK until "All stove elements are 120v, and wired so that
in normal use the load is equalized from each 120v bus to neutral". There is
only 120V (to ground) at any point, though.

 

[krw]

In my experience, the oven uses "two hots", for a total of 230V across
the element.

The stove top elements are between hot and neutral, for 115V. And on the
stove I used to work on back home, the stove elements draw 750W or 1500W.
So they don't need more than 115V to do that, for the stove top.

I've never seen such a setup. The stoves I've seen have only a clock, or
controls run off 120V. All heating elements are 240V.

 

[trader4]

I've never seen such a setup.  The stoves I've seen have only a clock, or
controls run off 120V.  All heating elements are 240V.

Thanks. I was beginning to feel lonely here. I'm not sure
there isn't a stove somewhere with a stovetop heating element
that runs off 120V. But I haven't seen one. They've had
240V heating elements. I'd like to see a schematic for
one of these 120V element stoves. Shouldn't be hard to
do if they are out there and common.