Overload?

[ThrownRazor25]

Right following on from my last post.

i rewired a pizza oven circuit as the oven was being moved.its done in 16mm twin and earth.protected by a 50 a mcb.

guynfoned tonight saying after half an hour the circuit tripped so went up the oven is 13 kw can this be an overload?should I put a 63a mcb in.

circuit always resets when mcb is put back so don't think it's a fault

many thanks

 

[44ALLAN]

Neva re-wire an oven when it's being moved or you'll have to start PAT testing it mate...............wait until it's stopped

 

[telectrix]

56.5A. could just trip the 50A after a while. esp if it's in a kitchen, high ambient temp. stick a 63A in, cable installation method allowing for such uprating.

 

[ThrownRazor25]

It's a brand new oven never been on before brand new pizza premises when I say moved I meant 3metres across the kitchen floor sorry

 

[44ALLAN]

I knew what you meant

 

[ThrownRazor25]

Cool thanks telectrix he was only doing staff training tonight and both fans I am installing aren't up yet they are coming tomorrow so he says the place was boiling once they had started.

 

[telectrix]

16mm, clipped direct will handle 87A, so you've got some latitude with your MCB.

 

[ThrownRazor25]

44allan thanks for the reply bud

 

[Marvo]

Maybe check the load of the oven with your clamp meter and decide from there if it's marginal overload or an intermittent fault.

 

[ThrownRazor25]

It's clipped in loft then in 50 x 50 trunking

 

[dan86]

Marvo beat me to it. that would be my next step

 

[44ALLAN]

44allan thanks for the reply bud

Sry mate couldn't resist

 

[Darkwood]

It's clipped in loft then in 50 x 50 trunking

This vital bit of info is a game changer ..... as its run through a loft unless measures have been taken to ensure existing or future insulation of the loft will not de-rate the ccc of the cable unless its been already implemented in design... then your running in trunking.... i see issues already in uprating mcb!..... although its an existing install you are making alterations to it and must ensure the circuit is fit for purpose..... 2yrs down the line someone lags the loft and 1week later Pizza shop burns down!!!!

Ironic that if it already runs through the insulation more than 100mm then the 50amp mcb is too big a set-up you hopefully have calculated if need be, if no insulation present you should ensure that installation of it will not effect cable... i use a warning notices to warn of fire hazards if insulation is fitted over cables in a loft and have my company details along with it.

 

[Darkwood]

56.5A. could just trip the 50A after a while. esp if it's in a kitchen, high ambient temp. stick a 63A in, cable installation method allowing for such uprating.

Check out post 10 WHOopps! Think OP may have some problems here after 2 threads he chucks in spanner!mg_smile:

 

[Rampantchilli]

Tbh honest I doubt consideration has been given previously to the installation method, as he can't even work out if 13kw is too much for a 50a breaker, a pretty basic sum