45A HRC Fuse or 50A MCB for Shower

[Shay]

Hi all, My house has a Memera 2000, split load consumer unit. One side is protected by a 30mA RCD.

I'm installing a 10.5kW shower. There are luckaly 2 apare ways on the RCD protected side of the board. All existing circuits from the board are protect by HRC Fuses.

Is it best for me to use the 45A HRC Fuse or a 50A MCB for the shower? I know the MCB reacts quicker.... but 45A is closer to the current of the shower... will putting a 50A MCB in slightly overrate the shower?

Also... is it good to mix and match protection devices in consumer units?... eg MCB, Fuse etc?

Thanks loads, Shay

[dcbwhaley]

Use the MCB. It gives much better protection because of the faster tripping time.. The rating of a fuse or breaker is the current that the device can carry continuously without tripping. Remember that the primary purpose of the breaker is to protect the cable. It can't affect the 'rating' of the shower.

On a 60amp load the 50A typeB MCB will trip sonner than a 45A DRC