Downgrading MCB to protect cable but has fixed load greater than IZ

[gooner80]

I can't tell you the complete laws of thermal dynamics or heat transference. It is like that at the switch and 30cm up from the switch. I ve seen quite a few instances of heat damaged cables the fishy smell is present

 

[hightower]

I can't tell you the complete laws of thermal dynamics or heat transference. It is like that at the switch and 30cm up from the switch. I ve seen quite a few instances of heat damaged cables the fishy smell is present

I've worked in one or two houses that had a fishy smell too. Had no cables burning though

Ohms law suggests it wouldn't with only around one-and-a-half milliamps flowing.

In answer to the OP's question though, a circuit breaker should not be used as a load-limiting device,

Yeah didn't have time to work it out this morning. You're right of course

 

[telectrix]

if Ib > Iz ( dependent on reference method of installation) then the cable is inadequate, irrespective of OCPD rating. end of.