jim the plumb wrote:But if a contactor is noisy, then I won't use it.
For sure, a 40amp contactor will make a loud “thud” when it pulls in!
ericmark wrote:However the question has to be why have an isolator? Although we will normally fit isolators on shower and cooker supplies there is nothing as far as I can see which says you have to have one. Look at a gas cooker and often there is no isolator either you switch off main supply or use a plug and socket arrangement which self seals as the spigot is released. How they get away with it I don't know but as far as I can see there is nothing to say you must have an isolator.
Well, according to my little book of the IEE Regs, it states for electric showers, “The heater must be controlled by a double pole linked switch. In the case of a shower heater, if this switch is not built in to the heater itself,” (which it isn’t) “ a separate pull switch must be provided adjacent to the shower……”
To be honest, I can’t be bothered to search the book for the exact wording, but as far as I am aware, all kitchen appliances are required to have isolators (usually a fused spur) in view above the worktop. Fine, built in hobs or ovens may be plugged in to a 13amp socket in a cupboard, but will still require the protection above.
ericmark wrote:So back to basic why do you want the supply to be removed from the shower unit when no one is in the room? When I have had an electric shower I never bothered turning it off.
Yeah, I wondered that too. I never turn mine off. There is no instruction to do so in the user handbook. The isolator is only for safety only. Some of the electronic showers have internal circuitry that will waste energy, so from that point of view, I could understand it may be desirable to kill the supply.
If the noise of a contactor is a problem, how about a solid state relay????