Wiring extractor fan

[DaveJ123]

Hi all,

The instructions for my 240v/20 watt bathroom extractor fan say that it *has* to be connected to a double pole spur. Why is this? (It’s a very cheap model - no timer, operated by a pullcord and has no earth btw. ) And since I actually want to use it in a bedroom instead, could I merely plug it into an ordinary single pole mains outlet and remove the plug when I’m not using it?


DaveJ

 

[breezer]

yes you can, the reason is that of saftey, if used in a bathroom it must be completley isolated if it is to be worked on i.e cleaned

 

[Scoby_Beasley]

I agree with breezer. Absolutely nothing in a bathroom should be on a single pole switch to help you live a long and fruitful life.
Any where else is okay to blow yourself up though

 

[Tin Gill]

Okay - silly question time...

What's a double pole spur?!

 

[breezer]

its better that you ask first than find out the hard way.

A doble pole anything means that it operates both poles, a pole being the live or neutral.

Normally only the live is switched off, but for extra saftey you have double pole switches etc, that switch both live and neutral off at the same time

 

[Tin Gill]

So how would the wiring for a double pole switch differ from a single pole switch?

 

[breezer]

a single pole switch only switches the live, so it needs one cable (2 cores one in and one out)

a double pole switch switches both live and neutral so it needs 2 cables (4cores, 2 in and 2 out)

for example if you were to wire a light via a plug you would only need to take the live and switched live to the switch (Just 2 wires)

but if you had a double pole switch you would need to take both the live and neutral feed to the switch and then froom the switch to the light

In practice what you would do (using the same light and plug) is take the cable from the plug to the switch, break only the live and up to the light (single pole)

Double pole you would do the same except that you would break the neutral as well as the live.

Double pole switches have 4 terminals, where as a single pole only has 2. (unless it is a two way switch but that is different again)

 

[DaveJ123]

Thanks breezer and Scoby_Beasley. Just as a check I asked on another forum -not that I doubted you in anyway, of course. But this is the internet after all. Anyway, they all said definitely no! Turned out, they were Americans, and to get 240v they connect across two live wires. Total confusion to start with, but once I explained that we have one live 240 and one neutral they could see what I was getting at.

Many hands make light work of spoiling the broth...or something.

Cheers

Jon