Electric oven tripping circuit breaker after turned on for 3-5 minutes

[ChaosLegionnaire]

Re: Electric oven tripping circuit breaker after turned on for 3-5 minutes

well, thats a pity. i am also experiencing a similar issue but its on my mother's LG washing machine. a few days ago, she used the hot water function to wash her clothes and it tripped the circuit breaker after a few mins. i think the short was so bad that it actually tripped the breaker outside the flat at the power meter!!

she said she hadnt used the washing machine's hot water function for over a month and decided to use it because of the cold weather. when i restored power, she tried resuming the washing with hot water, but i could smell a distinct burning smell coming from the washing machine tho it didnt trip the power *yet*...

i told her not to use the hot water function and to turn it off and wash with regular cold tap water. it looks like the water heater in the washing machine shorted also wtf!

i wonder if the same can also happen to the water heater for showering if u dont shower with warm or hot water for awhile... hahaha! sometimes the weather in sinkieland is so hot, i dont use the water heater for showering at all...

ah well... i guess my mom's washing machine is focked and can no longer be used to wash with hot water. guess i will have to take care not to soil my clothes or make my clothes too smelly... hahaha!

[beetle1303]

Re: Electric oven tripping circuit breaker after turned on for 3-5 minutes

I kinda forgotten this tread since I didn't get any email alert till now. My apology for not getting back on my final tests outcome.

This was the results:
- After a few days of intentional heat tests at various temperatures and duration, I reconnected the bad element. At lowest temperature setting 50C, it tripped within 3-4 minutes. I let it cooled for and hour and repeat - same outcome.
- I have since then disconnected this bad element, and use the oven regularly like 1-2 times weekly. Works like a normally good oven.
- When I received an email alert from @ktgohdt125 yesterday, I decided to re-try one more time - the result is still the same: it tripped within 3-5 minutes.

So, my take is, baking the presumed moisture soak element does not work..

[ktgohdt125]

Re: Electric oven tripping circuit breaker after turned on for 3-5 minutes

Yes, I intend to continue testing the elements in the quest of knowledge. At the end, if the elements are good and safe enough to use, then all is well. Otherwise, I would replace them, or look for a resale unit in the local online marketplace.

With this in mind, I have basically continue baking the elements. Started with Lower Heating mode at 50c, going up to 100c, and then switched to Upper and Lower Heating mode. I have ran it for ~3 hours today. I intend to do the same thing over the next days, but run it for ~6 hours at 100c.

The ultimate test will be to re-connect the upper element outer loop that was shorted to ground when last tested outside the oven. If this loop do not leak anymore, then it will prove that baking it works, and most importantly implying moisture absorbed after sitting idle for long period of the root cause.

Will update how it goes in few more days.

\
any updates??
i hv been repairing ovens and facing this kind of situation every now and then where oven trips if left unused for sometimes,

and from my experience if I force the suspected elements to heat up few times, it may trips a few times but after few trial, it will works without tripping. there are 2 oven that i rescue months ago now working flawlessly time being, will test it again this sunday if it will trips after i hv left it sitting there few weeks since last test....

[eccerr0r]

Re: Electric oven tripping circuit breaker after turned on for 3-5 minutes

Thinking about it again, is it really a RCD trip or is it excessive current shorting when hot? The latter is not really likely but still plausible if a large amount of current if the outside shield is more conductive than the heating wire. This somewhat makes more sense because when running the heating elements outside of the grounded oven, there shouldn't be a current leak. However you should see hot spots on the element.

But either way, the element should be replaced. Not safe.

[televizora]

Re: Electric oven tripping circuit breaker after turned on for 3-5 minutes

Measure the current during normal operation and during the fault conditions.
Also, measure any current to the ground. RDC-s trip if there is insulation fault and current to the ground.
Circuit breakers trip if there is a short circuit or excessive overload.
There has to be insulation breakdown somewhere. Or excessive moisture.
What I see is that you are from tropical country, this means lots of moisture.
Perhaps, it's a good idea to have also moisture absorber installed.
If the heating element is defective, moisture could soak up inside the heating element.

[eccerr0r]

Re: Electric oven tripping circuit breaker after turned on for 3-5 minutes

Someone needs to change this thread's index topic from "Circuit Breaker" to "RCD" or "GFCI" or RCCB even ... Ugh... this has been bothering me...

sorry, pet peeve...

[budm]

Re: Electric oven tripping circuit breaker after turned on for 3-5 minutes

The bad part is this, if the safety GND failed and the RCCB also fail (do you check its function once a month) so if some touch the stove that will be dangerous.

[beetle1303]

Re: Electric oven tripping circuit breaker after turned on for 3-5 minutes

Well, considering I have replaced a lot of mechanical thermostats, and I have never seen one that trips breakers, I'm going to say the thermostat is unlikely. What seems more likely to me is that all the elements have absorbed water to some extent. If you are dead set against replacing the elements, which I understand, I'd continue the slow low bake. You don't want the water expanding quickly, and maybe causing other problems. A 50C oven is probably 100C in the elements or more when it's on. If I had to guess, you are probably looking at somewhere between 8 and 48 hours to get all the water out.

Yes, I intend to continue testing the elements in the quest of knowledge. At the end, if the elements are good and safe enough to use, then all is well. Otherwise, I would replace them, or look for a resale unit in the local online marketplace.

With this in mind, I have basically continue baking the elements. Started with Lower Heating mode at 50c, going up to 100c, and then switched to Upper and Lower Heating mode. I have ran it for ~3 hours today. I intend to do the same thing over the next days, but run it for ~6 hours at 100c.

The ultimate test will be to re-connect the upper element outer loop that was shorted to ground when last tested outside the oven. If this loop do not leak anymore, then it will prove that baking it works, and most importantly implying moisture absorbed after sitting idle for long period of the root cause.

Will update how it goes in few more days.

[clearchris]

Re: Electric oven tripping circuit breaker after turned on for 3-5 minutes

Well, considering I have replaced a lot of mechanical thermostats, and I have never seen one that trips breakers, I'm going to say the thermostat is unlikely. What seems more likely to me is that all the elements have absorbed water to some extent. If you are dead set against replacing the elements, which I understand, I'd continue the slow low bake. You don't want the water expanding quickly, and maybe causing other problems. A 50C oven is probably 100C in the elements or more when it's on. If I had to guess, you are probably looking at somewhere between 8 and 48 hours to get all the water out.

[sam_sam_sam]

Re: Electric oven tripping circuit breaker after turned on for 3-5 minutes

Me personally I would not trust this element any more

[beetle1303]

Re: Electric oven tripping circuit breaker after turned on for 3-5 minutes

There is the outcome of tests done today:
1) Set oven to Lower Heating mode, temperature at 150c:
- it ran OK, nothing happened at 5 minute point!
- at ~25 minutes, thermostat clicked off
- at ~33 minutes, thermostat clicked on
- playing around with various heating mode and temperature, all OK.
- switched oven off after 60 minutes.

2) After letting cooled for few hours, I re-do a test: Lower Heating mode, temperature at 50c
- at ~4 minutes point, thermostat clicked off
- at ~15 minutes, thermostat clicked on.
- set temperature to 100C
- thermostat clicked on( and off after 10+ minutes)
- switched of oven after 60 minutes.

3) I repeated #2 after let it cool for 2 hours - all is good!

Now I am suspecting if all the power trips in the past were caused by the thermostat clicked off at 50c after 3-5 minutes of heating up???

But somehow cured itself after heating up repeatedly???

[beetle1303]

Re: Electric oven tripping circuit breaker after turned on for 3-5 minutes

This is what happens when you have an intermittent problem sometimes it works and sometimes times it does not work

At this point I would not trust this element at all
Here is why let just say that this element developed a semi short but not enough to trip the breaker right a way but enough to heat up your wiring and causing to catch on fire but you do not notice it right a way

This is not a good situation to be in

This is the reason why I would not trust this element any more

When I use to air conditioning service in a past life I would have customer who would bypass the grounding terminal on the unit because it was tripping the breaker and now it shocking them when they would touch the cabinet

Or

They would put in a bigger breaker so it would not trip

But the problem was that there compressor was semi shorting and need to be replaced

So if the coil shorted to the outer shell, this would caused an earth leak and trip the RCCB if the current leaked is >30mA. However, if the leakage is <30mA, then the earth wire could be heated up so much so that it could melt and burn?
My my education, can you help me to understand how this work -that 30mA leakage current could heat up the earth wire so much to melt and burn it, where as the live and neutral wire connected to the element that draws ~5A are OK?

[clearchris]

Re: Electric oven tripping circuit breaker after turned on for 3-5 minutes

Also make sure your connections are solid. If you have a loose connection, that can cause tripping.

[sam_sam_sam]

Re: Electric oven tripping circuit breaker after turned on for 3-5 minutes

This is what happens when you have an intermittent problem sometimes it works and sometimes times it does not work

At this point I would not trust this element at all
Here is why let just say that this element developed a semi short but not enough to trip the breaker right a way but enough to heat up your wiring and causing to catch on fire but you do not notice it right a way

This is not a good situation to be in

This is the reason why I would not trust this element any more

When I use to air conditioning service in a past life I would have customer who would bypass the grounding terminal on the unit because it was tripping the breaker and now it shocking them when they would touch the cabinet

Or

They would put in a bigger breaker so it would not trip

But the problem was that there compressor was semi shorting and need to be replaced

[beetle1303]

Re: Electric oven tripping circuit breaker after turned on for 3-5 minutes

Today I reinstalled back the upper and lower elements, re-connect everything except the leaking upper element outer loop. Everything as there were, without additional RCCB.

Here's some unexpected, but interesting outcomes:
- Set mode to Lower Heating only, temperate at 50c, this was the last time when it tripped in about 3-5 minutes. Not expected to trip now since I have tested it previously, in full power for more than 10 minutes without tripping. But it trip! After 6 minutes.
- So I was thinking it could be caused by thermostat issue when it clicked off at set temperature.
- I reset power, and rerun Lower Heating mode but now at at Max (~230c). After running for ~20 minutes, all is still good at it has not reached the set temperature. I then turn the temperature knob down slowly. I think point I was expecting it to trip again when the thermostat clicking off, but it didn't!
- So I played around the temperature knob, turning it up and down to hear it clicking on and off. Nothing happened. I also set temperature at 150c and it clicked off and on without issue.
- I also set mode to Upper and Lower Heating mode, repeat various temperature settings, all OK.
- In all, after ~60 minutes of heating at various temperatures, including turning off and on a few times, all is good now.

So what could be the issue on 1st power up?

***I guess I will redo these tests again tomorrow, start with same Lower Heating mode, but set temperature higher at 150c to see if it would trip again at ~6 minutes point, or when it reaches the set temperature.


-

[clearchris]

Re: Electric oven tripping circuit breaker after turned on for 3-5 minutes

I'd just not use the RCCB because it would require ripping more out of the oven or the wall socket. If you hook it up as you said, I'd consider that safe enough to not worry about additional protection. For the record, hooking up the elements on a clay pot was a bit dicey to me, but I'd be fine without an extra breaker in line if everything was hooked up in the oven.

[beetle1303]

Re: Electric oven tripping circuit breaker after turned on for 3-5 minutes

I wouldn't do that. Now that you know the bad coil, reassemble the oven with the good coils. Put the bad coil in and bake a low temperature. Obviously don't connect the bad coil, put it on a rack or don't attach the wires.

Edit: make sure you tape off any bare ends so they don't contact the case or anything else.

Good idea. I would re-install both lower and upper elements, and not connecting the bad element loop as you suggested. Then turn on at lower temperature for a few hours to see if the make any difference.

On the RCCB to isolate oven elements from tripping the house, I would like to know why you wouldn't do it - is it wired wrongly, or it wouldn't work as intended?

In fact, I have wired up the RCCB with the leakage wired to earth wire. When the element leaked, the house main RCCB tripped but the RCCB at the element side did not. I googled and gathered that with both RCCB of same 30mA rating, the main RCCB will trip first due to inherently already having some level leakage within the household circuits.

[clearchris]

Re: Electric oven tripping circuit breaker after turned on for 3-5 minutes

I wouldn't do that. Now that you know the bad coil, reassemble the oven with the good coils. Put the bad coil in and bake a low temperature. Obviously don't connect the bad coil, put it on a rack or don't attach the wires.

Edit: make sure you tape off any bare ends so they don't contact the case or anything else.

[beetle1303]

Re: Electric oven tripping circuit breaker after turned on for 3-5 minutes

Thanks for all the input and feedback. I appreciate them.

I am more interest in the learning than getting the oven working again. I mean I don't really the oven... So the quest for knowledge - identify root causes, probable solutions and fixes, etc, the journey is more fulfilling.

Here's additional test outcomes:
1) In a condone off corner of my living room (in from of my TV and laptop) , I wired up the elements: 3-element-in-series, 2-element-in-series, and 1-element-only.
2) I tested them one at a time, with live, neutral and earth all connected to wall socket.
3) I ran the 3-element-in-series for 1 hour, stopped for 10 min to cool, and repeated one more time. I repeated the same with the 2-element-in-series. All good, no power trip.
4) I then repeat with 1-element-only, but only for 10 minute since it would have tripped in 3-5 minute. As it turned out: the single loop lower element and the inner of the double loop upper element both OK after 10 minutes. The outer loop of upper element tripped in ~3 minutes!

So I have a working lower element, a half working upper element. And a more or less conclusion that baking the long idled elements for 1-2 hours won't fix the issue. I am guessing that baking longer hours might not help either.

Now I have one last quest for knowledge:
In trying to not tripping the whole house with each experiment, I found a spare RCCB in the storeroom. So I googled and research about this to see this RCCB can be wired up to prevent the power trip.

I googled and watched some youtube on this topics, and drawn up a diagram did some Ohms' Law calculations.

I am guessing this will work - please see attached pic.

Again, this is purely academic - it will not fix the element issue, but will enrich my basic electricity knowledge.

Advise and feedback will be very much appreciated.

[clearchris]

Re: Electric oven tripping circuit breaker after turned on for 3-5 minutes

measure the lengths and bend your own to shape .

I have done this, and it's much less fun than it sounds, even with a pipe bender. The unbent ones tend to be more expensive than a replacement part too. I wouldn't have done it if I didn't need it custom. It was to add an extra defrost coil to a walk-in freezer that kept freezing solid.

At least it worked great when it was done.