Hi, I would be grateful for an opinion from someone in the know: I had an electric shower fitted by a firm of electricians. They took a cable from the old style fuse box and into a 63A circuit breaker with a 30 mA RCD. So far so good. The cable runs to a twin pole isolator pull cord switch in the bathroom ceiling, and from there to the shower.
I wanted a spur to a convector heater, which I took from the shower side of the isolator switch. I calculated that the shower and the heater together would draw 48A. I assumed that this would be fine on a 63A circuit.
The system worked for about 6 months and then I lost power to the shower and the heater. The circuit breaker had not tripped. I then discovered that the isolator was rated to only 40A and the contacts had been burned out by the 48A load.
My question is whether a 40A switch on a 63A circuit conforms to Chapter 17? Or was it my fault for not considering the load on the switch?
I wanted a spur to a convector heater, which I took from the shower side of the isolator switch. I calculated that the shower and the heater together would draw 48A. I assumed that this would be fine on a 63A circuit.
The system worked for about 6 months and then I lost power to the shower and the heater. The circuit breaker had not tripped. I then discovered that the isolator was rated to only 40A and the contacts had been burned out by the 48A load.
My question is whether a 40A switch on a 63A circuit conforms to Chapter 17? Or was it my fault for not considering the load on the switch?