beckyj144 said:
can someone help please we have a garage unit with a 63 AMP 30mA main switch with a 16a for sockets and 6a for lights the cable supplying the garage appears to be getting warm and i think is a 2.5mm cable from a 16a mcb in the main box.Is this ok or shold cable be capable of carrying 63A?
Several things here - the "main switch" you mention is probably an RCD (have a look, it should say so) in which case as well as acting as a manual switch it will switch off automatically if there's a fault which causes 30mA or more of the current from the Live wire to go somewhere other than the Neutral wire, such as through a person. This is a useful safety feature!
The "63A" rating is the current the RCD can handle, but it won't switch off if this is exceeded, that needs an MCB or RCBO - it's just possible you have the latter, but unlikely.
The current in your garage cable is protected by the 16A MCB in the house, and as that's well below the rating of 2.5mm² cable, a cable overload isn't the cause of the cable warming, unless the cable is damaged in some way, or turns out not to be 2.5mm².
Let's assume that the warming only happens when you are using something in the garage (so there is current flowing) and the warming is only at one end or other - the warming is being caused by a high resistance in a connection at the end that's getting warm, and the possibilities are that it was connected badly originally, or the connection has gone bad by, for instance, the screw loosening-off. So someone needs to check the connections at the warm end, and see if something is amiss there. If my assumptions above are wrong, ignore this paragraph, it's something else!
Cheers,
Howard