At the moment, I have an immersion heater in airing cupboard - draws 15 amps. It is currently on a 15A single dedicated circuit protected by 15A MCB at consumer unit. Circuit cable is 2.5 twin and earth.
I would like to change the rating of the circuit - replace 15A MCB with 20A MCB - an electrician will do this. I would then spur off the immersion heater switch to an RCD (30ma) and on to a 5A FCU for the shower pump.
But, this leaves the immersion tank switch/heater potentially vulnerable to a 20amp surge (I think). How do I protect against this?
Can I put a 15A FCU in for the immersion tank, and spur from that?
Please assume that at some point the shower pump and the immersion heater will both be working - and then the draw on the circuit in total 20A...
If I can/should put a 15A FCU at the immersion tank - where can I buy one? I have only seen 13A rated FCU's. I am not sure; would it be ok to put a 15A fuse in a 13A rated FCU? Or would the connections in the FCU burn out when taking 15A? (I leave the immersion tank switch on all of the time).
I noticed some earlier posts on this set up - but am not sure that this question (or state of confused ignorance) was presented...
Airing cupboard is outside of zones.
V Grateful for any help...
Dinman
I would like to change the rating of the circuit - replace 15A MCB with 20A MCB - an electrician will do this. I would then spur off the immersion heater switch to an RCD (30ma) and on to a 5A FCU for the shower pump.
But, this leaves the immersion tank switch/heater potentially vulnerable to a 20amp surge (I think). How do I protect against this?
Can I put a 15A FCU in for the immersion tank, and spur from that?
Please assume that at some point the shower pump and the immersion heater will both be working - and then the draw on the circuit in total 20A...
If I can/should put a 15A FCU at the immersion tank - where can I buy one? I have only seen 13A rated FCU's. I am not sure; would it be ok to put a 15A fuse in a 13A rated FCU? Or would the connections in the FCU burn out when taking 15A? (I leave the immersion tank switch on all of the time).
I noticed some earlier posts on this set up - but am not sure that this question (or state of confused ignorance) was presented...
Airing cupboard is outside of zones.
V Grateful for any help...
Dinman