MCB Tripping on Oven

[nabby68]

Hi
We have a range oven 6kw connected with 6mm T&E on a 32A MCB. The oven was installed 4 years ago and had worked fine. We had it cleaned about two weeks ago. Yesterday whilst using both ovens and the grill the MCB tripped. Tried to reset but wouldn’t. Turned oven off and it reset. Then restarted oven then grill and then oven again. After 5 mins tripped again. Turned everything off. Used oven and grill this morning and after 15 mins MCB tripped. Any help appreciated.

 

[blup]

The cleaning process might have loosened a connection within the oven or at the isolator, or it may be coincidence.

An electrician can test the circuit and identify the likely cause. If you feel competent you could check for loose connections having safely isolated the circuit.

Blup

 

[bernardgreen]

might have loosened a connection within the oven

Loose connections seldom cause an MCB to trip because loose connections cause a reduction in current

A loose connection will only trip an MCB if the MCB has arc detection ( very unlikely ) or the loose connection allows a wire to come loose and touch earthed metal.

 

[blup]

I suppose the loose connection could be shorting to earth.

Blup

 

[BS3036]

I would have expected a short to earth on one of the elements. If the OP could try each element independently it may be possible to isolate which element, though it may not be enough current to trip the MCB that way. Worth a try though.

 

[Taylortwocities]

@nabby68 are you sure it’s an MCB that is tripping? Does it have a test button on it?

 

[nabby68]

It’s definitely the MCB. It doesn’t have a test button on it
Thanks

 

[securespark]

I've had customer's ovens tripping when they reach a certain temperature.

Traced to a faulty element.

 

[blup]

This video might assist:

Fault Finding - You Will Never Guess What It Was... - YouTube

Blup

 

[securespark]

Try one element at a time and see if it trips.

 

[Harry Bloomfield]

Try one element at a time and see if it trips.

A failing element maybe only causes a trip, when other elements are also drawing current. Basically the fault, being the last straw and enough to cause a trip. Sometimes, you can spot a failing element by carefully examining each one, under a good light, along their entire length.