Does this require RCD protection?

HappyHippyDad · Feb 5, 2019

I have been asked to connect a 9kW kiln to the consumer unit.

The consumer unit is in the garage and the kiln will also be in the garage.

All the cable will be surface mounted, probably in conduit.

It's a steeple series E consumer unit with spare ways on the non-RCD side and no spare ways on RCD side.

I had decided to fit a 40A MCB on the non-RCD side into a standalone RCD but having thought about about it, does it require RCD protection? I'm so used to making sure everything has RCD protection but I can't see that this meets any of the requirements to do so.

Also, I dont think there are any RCBO's that fit the steeple series E board are there? lastly, I have assumed there are no spare ways on the RCD side from the picture below (I haven't visited yet), what do you think? Cheers all

[ElectriciansForums.net] Does this require RCD protection?

Deleted member 26818 · Feb 5, 2019

From the information, you have supplied, it either does not require RCD protection, or can be designed so as to not require RCD protection.
Looking at the picture, it appears that it could be possible to change the busbars so that an extra circuit could be added to the RCD, though that might then exceed the RCD’s rating.

westward10 · Feb 5, 2019

Using your installation method no unless the earthing system dictates it for fault protection or manufacturers instructions state otherwise, if the latter then a local rcd could be fitted.

bill01803 · Feb 5, 2019

As previously said you do not need a RCD specially when loading a kiln with wet clay! It may be worth considering putting it on it's own switch fuse due the the amount of load it will add to the install for long periods.

HappyHippyDad · Feb 5, 2019

bill01803 said:
As previously said you do not need a RCD specially when loading a kiln with wet clay! It may be worth considering putting it on it's own switch fuse due the the amount of load it will add to the install for long periods.

Are you thinking specifically about the max demand of all the circuits in the CU with regards the limit of the 100A main switch?

bill01803 · Feb 5, 2019

I have changed many steeple main switches that have burnt out, not as many as CGD/Lewden though.

Wilko · Feb 5, 2019

Being a 643 times bitten person, I'd want the kiln to have RCD/RCBO somewhere. Just thinking it might not be the best maintained and tested bit of kit.