Bathroom extractor running continuously

[Jupiter01]

I should have paid attention to how the old extractor was wired in but I didn’t. I’m now finding that my extractor is running continuously.

It has 3 terminals: L,N,T

I have 3 wires in the supply side: live, neutral and switched live (connected to light switch)

I put the live into the L terminal, Neutral in N and Switched Live into T.

Can you please advise on where I’ve gone wrong.

Thanks in advance

 

[JohnW2]

I should have paid attention to how the old extractor was wired in but I didn’t. I’m now finding that my extractor is running continuously. ... It has 3 terminals: L,N,T ... I have 3 wires in the supply side: live, neutral and switched live (connected to light switch)

How do you know which is which?

I put the live into the L terminal, Neutral in N and Switched Live into T. ... Can you please advise on where I’ve gone wrong.

If that were truly what you'd done, you would not have done anything wrong - but, as above, are you sure that you have identified the conductors correctly?

If you had 'swapped' live and switched live, the extractor would only be on when the light was on (with no timed 'run on'). About the only way (provided the extractor is not faulty) I can think of that might result in the behaviour you're describing is if you had connected the neutral to L, the live to N and the switched live to T (i.e. if you had 'swapped' neutral and live).

Kind Regards, John

 

[donrkebab]

Your connections are correct. Either the timer needs adjusting or the timer/fan is faulty?

 

[Jupiter01]

I've just checked and realised that my extractor does not have a timer function. I purchased this:
https://www.toolstation.com/xpelair-vx100-100mm-extractor-fan/p36701

The above wiring is correct as I tested it with a testing stick before connecting to the fan: live, neutral and switched live (connected to light switch). Dos the switched live need to connect to the Live terminal and the Live into the T terminal perhaps?

 

[ban-all-sheds]

I've just checked and realised that my extractor does not have a timer function.

Then it doesn't have a T terminal.

I purchased this:
https://www.toolstation.com/xpelair-vx100-100mm-extractor-fan/p36701

So how can you have connected wires to L, N & T?

The above wiring is correct as I tested it with a testing stick before connecting to the fan

Those things are so unreliable as to be useless for this. If you relied on what it told you you could easily have misidentified the conductors. You need a proper 2-pole tester

Dos the switched live need to connect to the Live terminal and the Live into the T terminal perhaps?

No.

 

[Jupiter01]

Thanks for the response @ban-all-sheds.
I definitely have a terminal for T but there is no wire going from this into the device. In the light of your response above, any cable going into the T terminal is just being terminated into that terminal joint? In my case, this is the switched live.

On the fluke testing stick, is it really useless? It's been 100% accurate in my experience. My general use of this is as follows: test it on a known circuit, switch this on and off to verify and then try on circuit at hand and again verify whilst switching on and off. I know there are added benefits of a 2 pole tester but thought the stick works well for these purposes?

Thanks for your help.

 

[donrkebab]

Put the permanent live into T, as it is not required. The switchline and N into L and N, the fan will now run only when the switch is ON.

 

[bernardgreen]

I know there are added benefits of a 2 pole tester but thought the stick works well for these purposes?

"The Stick" is in reality a 2 pole tester, the person holding it being one of the poles. All it can safely do is detect a difference in potential between the wire it is touching and the person who is holding it. It can give false readings and in some cases indicate that a wire is electrically dead when in reality the wire is live.

 

[Jupiter01]

ohh...

It can give false readings and in some cases

That's very damning as that one case, could be the one where I get electrocuted! I recall a similar conversation on one of my earlier posts and I must be honest, naively, I ignored the advice as the stick as served me very well. If the above is true, it simply cannot be relied on. This begs the purpose, when do folks use the stick? Is it of any use for working on live when changing light fittings over or sockets, etc.

Thanks for your help.

 

[bernardgreen]

If the above is true, it simply cannot be relied on

The "sticks" rely on the body of the person holding them being close to ground potential. 99% of the time the person's body potential will be close to ground and the stick's indication is then likely to be correct. If the person is close to live wiring then the person's body potential can be raised by capacitive coupling to a potential that is higher than ground potential.

 

[Jupiter01]

Thanks @bernardgreen. That's helpful. I do a reasonable amount of electrical work as part of my DIY endeavours and would like a safe and reliable companion when it comes to testing live wires and such like. Is there a tester you can recommend in this situation please?

 

[bernardgreen]

A good ( not E-bay special ) multimeter from a reputable manufacturer / seller. Fluke are good but expensive.

I still use an ancient Fluke 77 multimeter, more than adequate for all but insulation testing . A TEM-1555B insulation tester bought from a yard sale is my portable insulation tester.

 

[Taylortwocities]

The one thing that those volt wands cannot do is detect the presence of a neutral(or lack of).
Knowing that there is a neutral is as important as anything else, especially if you have something that doesnt work.
As above, get yourself a two pole voltage tester, or even a low-cost multimeter.
You really should have one, given the number of basic posts you have on this and other forums.

PS, do enjoy watching the build up of mould etc on your bathroom walls.
You really, really should replace the fan with a timer version.

 

[Jupiter01]

Thanks @Taylortwocities. I will also swap the fan out for a timer version.
Assuming this, does my switched live then go into the T terminal and permanent live into L?

 

[donrkebab]

Thanks @Taylortwocities. I will also swap the fan out for a timer version.
Assuming this, does my switched live then go into the T terminal and permanent live into L?

Correct