nominal current rating of main switch

[foghorn]

hi guys if installing a shower consumer unit with a 63amp rcd main switch and a 100 amp OPD PRIMARY SUPPLY then main switch is of a lesser value than the main over current protective device how do we get around this.

 

[snowhead]

What rating is the shower circuit MCB?

Written answer not required.

 

[foghorn]

40 amps

 

[Darkwood]

Snowhead was indirectly giving you your answer... The Circuit OCPD for the shower circuit will ensure the rcd rating is never exceeded can we assume that the circuit has overload protection and that someone doesn't think rcd's protect for overload? (Several fully qualified Sparks have posted over the years thinking that rcd's give overload protection) :blush5:

 

[amlu]

100amps incomer - 40A mcb - 45A switch - shower