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Baker1988

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Hi every one how are you all today? Can any one tell me whuch regulation says that a shower must have a isolator switch as i have recently witnessed a electrician put a new shower circuit in that was wired straight from the consumer unit to the shower and no isolater inbetween. I told him that it should have a isolator switch and he said that the mcb in the cu is the isolator switch and i dont think that is allowed or am i wrong.
 
Been doing a bit of research and Reg 537.1.2 allows N not to be switched in TN-S and TN-C-S systems so you only need a isolation switch in T T systems and in TN-S and TN-C-S a mcb would be andequate. Is that right?
 
I had a shower replacment a while ago that had no isolator and was fed from henley blocks as no spare ways on the board, similarly the amount of people that think an rcd does fusing because it has a rating of 40amp on itor think its a trip switch so thats ok, seen a couple like this.
 
I think it's a good idea to fit a nice chunky DP 50A isolator for the shower & fit it outside the bathroom so ye can switch it off when Your Lass is in the shower.
 
Sorry, I have disagree with your statement above.
A shower unit is an instantaneous water heater with an immersed and uninsulated heating element, so the 554.3 group of regulations apply. Particularly 554.3.3 which states: "The heater or boiler shall be permanently connected to the electricity supply through a double-pole linked switch which is either separate from or within easy reach of the heater or boiler or is incorporated therein, and the wiring from the heater or boiler shall be connected directly to that switch without the use of a plug and socket-outlet; in addition, where the heater or boiler is installed in a room containing a fixed bath, the switch shall comply with section 701."
 
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Are you sure? Last time I dissected a shower, the heating unit was constructed like a pair of kettle elements - not just a bare coil of wire in the water.
These modern plastic tank variety would be lethal if they had uninsulated elements, wouldn't they?

After finding a shower isolator in an unusual place on a PIR, I scoured the BRB for a pertaining reg, but couldn't find one.
I asked the question on here....
As D Skelton says, that's because there isn't one.
But the product must be installed in accordance with manufacturer's instructions - and they say to fit one!

Simon.
 
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If the instructions say to fit one then you must fit one, if not, then you don't. @MarkieSparkie, a shower is neither a heater or boiler... It's a shower. That's why the 554.3's don't apply.
 
If the instructions say to fit one then you must fit one, if not, then you don't. @MarkieSparkie, a shower is neither a heater or boiler... It's a shower. That's why the 554.3's don't apply.

Rule 554.3 may not apply BUT common sense says that fitting an isolation switch is good practice and that's why one should always be fitted.
 
and i'm still banging my head against the wall, trying to educate customers that it is an ISOLATOR, not an ON/OFF SWITCH
 
I have to go with Markie on this one the word shower does not relate to heating of water it is a noun a brief fall of rain, or an abundant flow and as verb to make wet or pour forth .............OED for that.

So I would definitely class it as a water heater, and I would class it also to be immersed, though whether it's uninsulated....... open to definition.

I personally would take reg 554.3.3 and associate it with a shower.

But as DS says if the unit itself incorporates a double pole switch then not fitting a separate would IMO not contravene the regs

As the internal shower switch will be rated for on load isolation, that would cover isolation as well
 
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Rule 554.3 may not apply BUT common sense says that fitting an isolation switch is good practice and that's why one should always be fitted.
Why is it common sense? Showers always have an integral off switch and they can be isolated at the CU so why do they need another point of switching off?
 
Regulation debate aside for a moment, I've never understood the need for an Isolator with showers.

Were anything to go wrong and the shower, or water passing through it to be come 'live' what use is an isolator? For maintenance you have the MCB/RCBO. For switching the shower on and off you have the usefully named on/off switch.

I'm happy to admit that my feelings on shower isolators maybe influenced by trying to bend 10mm into the terminals and box, but I just don't see why the manufacturers or anyone else sees the need for them.
 
Also, if the DP switch is for isolation only and not for functional switching then

why is it placed at 'normal' switch height or have a pull-string at the same usable height as a light switch.

Some showers have a light on continuously signifying 'power on' so

you can't blame the occupants for switching it off for the twenty three and a half hours a day when it is not being used.

Without a switch the only way the power light could be switched of would be the mcb or removal of the fuse.
 
I'd call it good practice to fit one regardless of fine print in the regs or manufacture instructions.

Although I can't say i've ever used mine since I put it in, 4 years or so ago. I always go with non-neon ones for this reason
 
interesting comments and views guys, just to add all it says in building regs guide about shower units is "It is normal practice to provide an isolation switch within the bathroom. The switch must be installed outside zones 0, 1 and 2 although the cord of cord operated switches may reach into zones 1 or 2"
 

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