Is 6amp feeding 100amp main ok? Ask questions and find answers to many subjects relating to electrics and electrical work

[Debutant]

If I have a mcb in a consumer unit rated at 6amps which feeds a small enclosure with a 100a main switch am I right in thinking the main switch rating doesn’t matter as it’s protected by the first mcb in the circuit? Cable size is 1mm

[Mr White]

So long as anything after the protective device is rated higher that said protective device all is good.

So in your case you have a 6A MCB and 1mm cable, and a100A switch all is well.

[Debutant]

Thank you

I’m pretty sure that as long as the upfront/ first device is adequately sized to protect the cable within the installation any other devices or switch rating do not matter.