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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?
The circuit protective device to a 100 kW motor circuit does not have to provide overload protection to the circuit cable, just fault protection.
The overload protection is provided by the motor starter.
The arrangement you describe seems perfectly reasonable in a situation where there are two motors that one will not be run simultaneously with the other, for example one is a backup water pump that can be used whilst the other is out of action.
So long as there is a method of working that stops both motors being run at the same time, which could be as simple as having a lock off isolator which is moved from one motor isolator to the other as they are swapped over in and out of service, there’s absolutely no problem at all and as such equipment would be supervised by competent people there’s no problem at all with the arrangement.
If I turned up and wired a new shower up in a garage conversion by piggybacking it off a cooker switch on the other side of the wall in the kitchen you are saying that is a perfectly acceptable design and installation, so long as the customer knows they cannot use them both at the same time.
The circuit protective device to a 100 kW motor circuit does not have to provide overload protection to the circuit cable, just fault protection.
The overload protection is provided by the motor starter.
The arrangement you describe seems perfectly reasonable in a situation where there are two motors that one will not be run simultaneously with the other, for example one is a backup water pump that can be used whilst the other is out of action.
So long as there is a method of working that stops both motors being run at the same time, which could be as simple as having a lock off isolator which is moved from one motor isolator to the other as they are swapped over in and out of service, there’s absolutely no problem at all and as such equipment would be supervised by competent people there’s no problem at all with the arrangement.
If I turned up and wired a new shower up in a garage conversion by piggybacking it off a cooker switch on the other side of the wall in the kitchen you are saying that is a perfectly acceptable design and installation, so long as the customer knows they cannot use them both at the same time.
