Siemens RCCB 5 SM1312 25A 30mA

[Malcolm Green]

I have a Siemens RCCB 5 SM1312 25A 30mA and my Fan Assisted Cooker/Grill keeps triggering it. When I first switch on it is fine then after a minute or two the RCCB is triggered and cuts the power. Someone has told me to increase the relevant breaker from 25A to 32A. Could this be a solution? If so is it possible to get a 32A breaker for this unit? Is it straight forward to change?

Thanks
Mal

 

[SparkyChick]

Hi Malcolm,

Welcome to the forums.

It's never a good idea to randomly start upgrading circuit breaker ratings. Their primary purpose is to protect the installation and as such you could find you are able to overload the cable and cause problems (possibly a fire). So in short, I wouldn't be taking electrical advice from whoever suggested it.

If the RCD is tripping it is because there is an earth leakage fault (or sufficient leakage to trip the RCD - this could be a result of the combined leakage on all circuits protected by the RCD and may not be a fault as such).

Is it a new cooker? Is it in use regularly or has it not been used for a while? I ask because it could be damp in the heating elements if it's been in storage for a while or it's not been used for a long time.

Has the tripping just started or has it gradually become more frequent?

If it's been in regular use and it's just started (or has gotten worse over time), I would say it's more likely to be a fault than an issue caused by damp.

 

[plugsandsparks]

I think that device is a 61008, so increasing to 32A will make no difference as 25A is its current handling not trip. The trip will be caused by earth leakage from somewhere or a fault with the device.
Needs clamping with an earth leakage clamp meter when you are operating it to see what is going on. Until you know whats wrong, i.e. RCD, wiring, other devices, N-E fault, fan unit, heater element etc , you are guessing... cheers P&S

 

[Malcolm Green]

Hi Malcolm,

Welcome to the forums.

It's never a good idea to randomly start upgrading circuit breaker ratings. Their primary purpose is to protect the installation and as such you could find you are able to overload the cable and cause problems (possibly a fire). So in short, I wouldn't be taking electrical advice from whoever suggested it.

If the RCD is tripping it is because there is an earth leakage fault (or sufficient leakage to trip the RCD - this could be a result of the combined leakage on all circuits protected by the RCD and may not be a fault as such).

Is it a new cooker? Is it in use regularly or has it not been used for a while? I ask because it could be damp in the heating elements if it's been in storage for a while or it's not been used for a long time.

Has the tripping just started or has it gradually become more frequent?

If it's been in regular use and it's just started (or has gotten worse over time), I would say it's more likely to be a fault than an issue caused by damp.

 

[Malcolm Green]

Thanks For your reply.

Actually the cooker is brand new. We purchased a the property a couple of years ago and had the same problem with the cooker already installed. So thought it was a dodgy cooker so decided to replace it and still have the same issue! Looking at the cooker that was originally installed whilst it looked quite old there was not a mark inside and looked like it had never been used! The property only had one previous owner an I assume the previous owner also had the same issue and therefore never used the cooker since they purchased the property from new. Does that give you any more clues?

Thanks
Mal

 

[Malcolm Green]

I think that device is a 61008, so increasing to 32A will make no difference as 25A is its current handling not trip. The trip will be caused by earth leakage from somewhere or a fault with the device.
Needs clamping with an earth leakage clamp meter when you are operating it to see what is going on. Until you know whats wrong, i.e. RCD, wiring, other devices, N-E fault, fan unit, heater element etc , you are guessing... cheers P&S

 

[Andy78]

Thanks For your reply.

Actually the cooker is brand new. We purchased a the property a couple of years ago and had the same problem with the cooker already installed. So thought it was a dodgy cooker so decided to replace it and still have the same issue! Looking at the cooker that was originally installed whilst it looked quite old there was not a mark inside and looked like it had never been used! The property only had one previous owner an I assume the previous owner also had the same issue and therefore never used the cooker since they purchased the property from new. Does that give you any more clues?

Thanks
Mal

This could indicate a fault on the cooker circuit if it has been happening with different appliances. Get a local electrician to check it out for you.

 

[plugsandsparks]

oops. look like you already guessed it was the cooker, thats one out of the way, the rest need test equipment and someone capable of using it, what other ccts are fed from the RCD, i.e. what goes off as well as the cooker ?

 

[Malcolm Green]

oops. look like you already guessed it was the cooker, thats one out of the way, the rest need test equipment and someone capable of using it, what other ccts are fed from the RCD, i.e. what goes off as well as the cooker ?

Just the gas hob igniter nothing else.

 

[Octopus]

I hate to state the obvious but unless you have proper test kit and the competence to use it and interpret the results nothing is going to change .

A spark could test the circuit for you ............... but it will cost........

 

[davesparks]

Actually the cooker is brand new. We purchased a the property a couple of years ago and had the same problem with the cooker already installed. So thought it was a dodgy cooker so decided to replace it and still have the same issue!

That’s an expensive way to find out that it’s not the cooker at fault!

 

[Malcolm Green]

That’s an expensive way to find out that it’s not the cooker at fault!

Yes I agree but it seems the only way I can go?!

 

[Andy78]

Yes I agree but it seems the only way I can go?!

A callout from an electrician would have cost less than a new oven. That's what you should do when devices that are designed to operate under fault conditions are operating.

 

[plugsandsparks]

Just the gas hob igniter nothing else.

Well that narrows it down a bit, if the fault is consistent and predictable an electrician should find it in an hour and as the most expensive part is the RCD, its worth giving a local electrician a call. He needs an RCD tester and a clamp meter, i know alot dont travel with these , so might be worth making sure he/she has them on his/her person before venturing out to chez MG... cheers P&S

 

[davesparks]

Yes I agree but it seems the only way I can go?!

You could have called an electrician in and paid quite a bit less than the price of a new cooker to diagnose the problem.
Now that you’ve bought the cooker you are considering replacing an RCCB to see if that fixes it?
This means opening up the consumer unit where there are live parts which you may not be able to isolate, so it’s not just your money you are risking but potentially your life.