How to connect Bathroom extractor fan

[Glen dyson]

Im just replacing a fan in my bathroom, there is only 3 wires coming from the ceiling live neutral earth ? The old fan used to switch on and off with the light switch outside the bathroom, ive wired the new fan up live and earth because they are the only terminals in the new fan , the fan is now permanently on even with the light switched off , is it possible who ever wired this up has used the earth wire as the switched live ?

 

[terryplumb]

Do you mean that you have connected live and neutral to the fan ? You should not have connected the earth ,if the fan doesn't have an earth terminal !!
Show us a pic of wiring at fan terminals.

 

[Glen dyson]

Hi sorry im at work now i cant get a pic, but yes i have just connected the live and neutral wires but not the earth wire because the new fan does not require an earth , but the more I think about it all these fans require a live and a switched live ,so has some one just used a 3 core wire and used the earth as the switched live

 

[terryplumb]

Only fans with a run on timer need switched live ,permanent live and neutral ( and possibly an earth).
Did your old fan have a timer function? ( After turning light switch off ,the fan continued to run for several minutes )?

 

[Glen dyson]

That is the old one that came off if you can see the wiring the yellow earth cable was in one of them blocks ?

 

[Glen dyson]

Yes the fan did run for a few minutes after been switched off

 

[terryplumb]

I think your new fan is a standard fan ,no timer ,with only two terminals. Are your cable colours red ,yellow and blue by any chance ?
If so the yellow is not an earth it is a live. Earth would be green and yellow sleeve over bare copper.

 

[Glen dyson]

Yes that’s correct, so do i need to put the yellow switched live to the live terminal and the permanent live red wire to the block with nothing connected to it ?

 

[terryplumb]

A fan with run on timer is a better proposition. The one you have will turn off as soon as the light switch is turned off ( once it is wired correctly) but that will not extract long enough to clear the room after showering etc.
If you decide to keep it ,then it requires the neutral and the switched live connecting ,and the unused permanent live put into an insulated terminal block ,held within the fan housing ,but not connected to anything.

 

[Glen dyson]

That’s brilliant thanks for the help , I think the yellow is an earth wire but it has been used for the switched live because you can see the wiring on the old fan when I took that down the yellow wire was connected to one of them in the block and none of those are earth ?

 

[terryplumb]

If your cable colours are red ,blue,and yellow it is a three core and earth cable. If you look closely at its outer sheath you will likely see a bare copper conductor that has been cut near the end of the outer grey sheath.

 

[Glen dyson]

Oh ok i have not noticed that but there is some tape higher up the wire so it could be in there , what i will do when i get home is check that yellow wire to see if that is the switched live im sure it must be

 

[terryplumb]

Sounds like it. If only the red and blue are connected to the fan ,and it runs continuously ,then the red would be the permanent live . Take a look and see when you get home,let's know how you get on .

 

[Glen dyson]

Will do thank you

 

[dontbelieveawordofit]

.