New cooker keeps tripping

[Richskirich]

Hi,

We have a new cooker. Upon wiring it in the the RCD trips rated at 80A but the MCB doesn't rated at 40A. The cooker draws 8.5kW. it trips as soon as the double pole switch is made. The manual says use 2.5mm² which I am but my maths it should be bigger. Anyway, I feel like it is a fault with the cooker. Probably shouldn't have, but when I disconnected the earth at the cooker the came on. Surely a cooker wouldn't be drawing much current when nothing is actually turned on, on it. Any advise or ideas? 230V as in the UK.

Thanks!

 

[sircerebus666]

You have an earth fault which is why the RCD trips but the MCB doesn't

Are you utterly sure you have wired it in correctly ?

Some pics of the wiring at the cooker and at the connection plate would be useful

8.5kw is too much for 2.5mm cable , 4mm is better I wonder if they took diversity into account?

Can you show us a pic of where it says that in the manual?

 

[sircerebus666]

Just noticed you have it connected to a 40a MCB you need to go up to 6mm cable

 

[JohnD]

when I disconnected the earth at the cooker the came on.

is there a word missing?

I think you've wired it wrong.

photograph the connections in the switch, the outlet, and the cooker please/

 

[Richskirich]

Unfortunately it's unwired at the moment for the night.

I thought it would be 6 but the manual said 2.5. I'm attaching a picture.

Sorry, I meant to write that when I disconnected the earth..ie live and neutral still connected, the cooker turned on when I made the switch.

 

[Richskirich]

Would the wrong size cable make it trip even if it is only drawing current for the LCD screen?

 

[sircerebus666]

That manual says 4300w which 2.5mm would be suitable for, however you would need to change the mcb

 

[sircerebus666]

Would the wrong size cable make it trip even if it is only drawing current for the LCD screen?

No but incorrect wiring would

 

[Richskirich]

So it's not tripping because of the incorrect wire size or MCB? Although the MCB is too highly rated.

So it is possible that the cooker has an earth and it isn't my wiring?

 

[sircerebus666]

No, incorrect wiring or a faulty oven would cause the RCD to trip

So yes it could be the oven but without pics of your wiring we won't know for sure

Do you own a multimeter ?

What's the ovens make and model ?

 

[sircerebus666]

That manual says 4300w which 2.5mm would be suitable for, however you would need to change the mcb

What wattage does your oven actually draw, is it 4300w as the manual says or 8.5kw as you say? What does the rating plate say?