Mitre saw tripping main breaker - Help!

[AllanW]

Well the garage CU is obviously of the same era so that kind of makes sense.

But no RCD protection - not good.

Can you see how the SWA cable is terminated, has it got a proper gland? (brass thing, usually sheathed with rubber condom-like cover, grips the steel wires and usually has a brass ring tag "banjo" that earth is connected to)

I see 3 cables off the socket circuit, so it is not (all) a ring and that might be why they are on 16A and not 32A as 2.5m radials are not rated for above 20-25A depending on the thermal conditions.

Is there a ring of a few sockets and another odd socket added somewhere? Or is it 3 radial circuits?

The 3 cables, one leaves clockwise, runs around 4 double sockets and returns is that a ring circuit? Then one runs as a spur heading anti clockwise to a double socket where I plug in my compressor and extractor when I'm spraying stuff. Yesterday I installed another spur through a 20amp switching box to a 16amp blue socket and plug for the chop saw but obviously it still trips. The only reason I use the 16amp circuit is because the cabeling is all 2.5 and I thot it would have to be 4 or 6 mm for the 32 amp circuit.
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Jeez you have given me so much valuable information, I really appreciate it. Wish you were local I'd give a good few jobs for it and the others in the house. I will double check the ring circuit by the advise and any doubts at all I will contact a proper electrician to change unit and make the necessary adjustments . Thank so much pc1966 wish everyone was as helpful as you and hope I could help others with knowledge I have too.

 

[pc1966]

Best plan is to get a local spark in. They can look at all aspects and hopefully get it safe and reliable by checking the supply arrangement and addressing the lack of any RCD protection, and lack of replacement parts.

While they are in you can also look at emergency lights as it seems it is used as a workshop.

 

[marconi]

Re #1: The OP reported:

I've recently moved into a new home where, the first time I used the saw there were no problems at all.

A week later I take the saw out and pull the trigger. The blade spins for an instant, stops immediately and the main breaker is tripped.

For the OP: What work have you done in your home and where during the week you mention? The electrician you call in will need to know.