Underfloor Heating over 13A??

[Philpot]

Roger if the voltage is higher the current will be higher and vice versa... a misprint? Mind you the current is not always what is says on the box!! I have found showers especially variable.
madger
Moses and a few others have given the answer....a seperate cct, contactors clunk and hummmmm.

 

[RogertheBodger]

Roger if the voltage is higher the current will be higher and vice versa... a misprint? Mind you the current is not always what is says on the box!! I have found showers especially variable.
madger
Moses and a few others have given the answer....a seperate cct, contactors clunk and hummmmm.

Yes you are right Philpot, didn't have my thinking cap on straight for that one.
I divided the load (3344W) by a voltage higher than 230V and came out with less current, but of course it's a fixed resistance and the current will rise with the voltage, so thanks for pointing that out.

As far as the thread goes, the OP has stated several times that he can't supply the underfloor heating with a new circuit, so he is looking for a way to put it on the ring, The load is a little big for a ring in my opinion but I assumed the floor was laid and just needed connecting. He has since said that the floor has not been laid and he is considering supplying a heating mat of 130Wm2 and not the 160Wm2 that was his original choice, so that would be the best solution, it would go on a 13A Fcu and eliminate the need for a contactor/relay.

 

[needasparks]

Is the mat/wire heating done as one element or multible elements coming back to the controller ? just thinking it could be split up across two fused spurs, one feeding each possibly.

 

[madger]

Thanks everyone for their input on this, multiple mats are being used - if worse comes to worse i can emit 300mm wide mat (manufacturer states that 100mm min gap from walls) also can trim some off each length of each mat. Not had much luck with regards to using power relay (as oppossed to contactor) for larger loads (above 16A rating of controller) on dedicated circuit. This i must confess is beyond my experience - have looked at so many relays with no idea what type would be most suitable.