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Two high-power appliances on a single 40A RCD
Former Community Member
I have an electric shower installed on a 40A RCD, in a room adjacent to my kitchen. The shower is only used in an emergency - i.e. when our gas boiler is unable to provide hot water to our main bathroom. I would like to take a spur from this 40A connection to use for a new double oven, which is rated at 32A. Can anyone advise on a safe and legal way to do this, ensuring that only one of the two appliances can be connected at any one time?
As I suspected the manufacturer has overstated the circuit requirement.
That oven will be quite safe on a 2.5 mm circuit with a 20 amp MCB or RCBO. That doesn’t particularly help if you don’t have such a circuit.
It is almost on the point of being able to be connected to a socket ring circuit with a 16 amp MCB at the point it is connected to that circuit.
4000 Watts divided by 240 volts = 16.7 amps, if you divide be 230 it comes out at 17 .4 amps.
If you look at a selection of double ovens you will find the manufacturers rating stated as required for the fuse or MCB doesn’t tally with the actual ratings they give for the ovens.
To be perfectly honest in my home I would prefer to see it connected to a socket ring circuit using a 16 amp MCB than connected to the shower circuit, after all the existing oven has been wired that way for many years.
Though I would still recommend a new circuit is installed.
That's interesting. The sockets in the kitchen are on a 32A circuit breaker in the consumer unit. A new circuit is really not feasible for me, mainly on grounds of cost. So are you saying that a separate 16 or 20 amp MCB could be installed in the kitchen - e.g. where the socket for the existing oven is located? (it's a double socket which is also used for a toaster).
As I suspected the manufacturer has overstated the circuit requirement.
That oven will be quite safe on a 2.5 mm circuit with a 20 amp MCB or RCBO. That doesn’t particularly help if you don’t have such a circuit.
It is almost on the point of being able to be connected to a socket ring circuit with a 16 amp MCB at the point it is connected to that circuit.
4000 Watts divided by 240 volts = 16.7 amps, if you divide be 230 it comes out at 17 .4 amps.
If you look at a selection of double ovens you will find the manufacturers rating stated as required for the fuse or MCB doesn’t tally with the actual ratings they give for the ovens.
To be perfectly honest in my home I would prefer to see it connected to a socket ring circuit using a 16 amp MCB than connected to the shower circuit, after all the existing oven has been wired that way for many years.
Though I would still recommend a new circuit is installed.
That's interesting. The sockets in the kitchen are on a 32A circuit breaker in the consumer unit. A new circuit is really not feasible for me, mainly on grounds of cost. So are you saying that a separate 16 or 20 amp MCB could be installed in the kitchen - e.g. where the socket for the existing oven is located? (it's a double socket which is also used for a toaster).
