Fire Risk Problem I cannot resolve.

[Captain Caveman]

Hi all, I've been working at a swimming rectfying many faults. The one major fault was bought to their attention after a fire broke out in a breaker.

The problem is i cant see why. The breaker and main incomers can get hot to the point of fire. The load is 20.2A on 16mm cable, the connections are fine, i have made them my self many times.

The ciriuit is being ran from a 32 way board, its ran 0ut of ways so the last electircian used a new two way board plus main 65A over load 30ma RCD, split betweeen two 32A ring mains. The breaker gets hot in the midle even though i have replaced it. The incomers i didnt replace, i dont kmow why some used 16mm cable either and at a load of 20.2A is it getting hot. The cables are rather bunched but i dont believe this is an eddy current problem?

 

[bigbaddave]

After a fire id be insisting on a EICR, Has this been done? Is so what has been highlighted as a result?

Theres clearly a fault and i would be finding what it was before even contemplation putting the power back on

Can you let us know the tests you have done and the results and this will help. Thanks

 

[i=p/u]

Faulty breaker, contacts damaged ??? High resistance, start with r1 and r2 tests

 

[telectrix]

failing which, take a loaf and a toasting fork. :hanged:sorry. 7 pints of ale inside.

 

[ayjay]

the breaker terminals were loose? 20 amps is **** all
sorry just re read, have you stuffed the outgoing cables at the back if said terms? i did that once
theres no way anything should heat up on a mere 20 amps
it must be a really small pool , to only take 20a

 

[onions1066]

It has to be the mcb, being bunched together shouldn't produce eddy currents I wouldn't of thought and it wouldn't have that effect one the mcb. How hot does it get and what make of mcb is it?

 

[snowhead]

What's the rating of the breaker that gets hot?

Which end of the 16mm cable is it, Source or Load?

How long is the !6mm cable run?

 

[Captain Caveman]

The rating of the breaker is a 63amp 30MA proteus , its being fed from a hager type 2 board C32 breaker. The whole length of the cable is the same temperature. The run is 50cm. The load is then split into 2 x B32 MCBs controlling two ring mains. After the proteus breaker the circuit is fine. I thought the first fire was caused by bad connection due to neutral side of the breaker have 4x2,5mm cables inside it. Their is no neutral bar in the second db, just 4x2.5mm connections on the main breaker? I cant see why this would cause these cables to get so warm. I made a typing error, the cables feeding the proteus from the hager mcb are meter tails!!!!!!!!

 

[onions1066]

50cm or metres?

 

[Captain Caveman]

This circuit is just for the heaters in the changing rooms this pool is pullins arouns 240 amps, 80 per phase

- - - Updated - - -

50cm's crazy and weird isnt it.