Correct Wiring 4 Ceiling light/fan

YDI_Try

Have read other threads on this topic - None have this wiring combination

Hopefully, should be fairly straight forward. The fan/light unit has the following connections:

Red - Light
Brown - Fan
Blue - Neutral
Yellow/Brown - Earth

From the ceiling there are 2 red and 2 black wires and an earth

Hopefully somebody can tell me what wires to connect from the ceiling to the fan ???

Cheers

matbe

are you trying to switch the fan and light seperately or are you going to use the chain switch built into the fan to control fan on and off and speed ?

YDI_Try

Hi Matbe,
The latter - Use the chain on the fan to control on/off/speed

matbe

did you note what was connected to what when you took the existing light fitting down?

most likely one red and black is a pair of mains (live and neutral )
the other is a switch wire and switch feed

YDI_Try

Unfortunately don't know what the original connections were.

Sorry but your gonna have to talk in laymans terms - i.e what colour wires in the ceiling go to what colour wires in the light unit

matbe

ok the two red wires go together in a connector block and do not connect to any of the wires on the fan

the earths go to the earth on the fan

this leaves two black wires

one of these wires is a neutral
the other becomes live when the switch is turned on


to find out which is which connect the reds together as explained

then seperate the wires from each other and test them one at a time with a neon screwdriver

the one that lights up when you touch it with the screwdriver (make sure lightswitch is turned on) is the live and this needs to be connected to the brown and the red wire on the fan

the one that does not light up is the neutral and needs to be connected to the blue wire on the fan

hope this helps

also remember the fan needs a very good fixing to the ceiling use at least 2 inch screws into a joist as these fans do vibrate quite a bit

andrew-b

If your unsure get someone in.

I know your trying to help matbe which i am sure is much appreciated by the original poster but i really don't think any of us should be advising the use of neon screwdrivers to test live connections - even if that is the way you or any of us here might solve the problem. Sure it will save OP money by not getting an electrician in...but saving a few pounds should not be for the sake of compromising one's safety.

I know our paths have crossed before on electrical safety here but it's really nothing against you and i realise you mean well! But we don't know YDIs abilities or knowledge - and even if we did we still don't know who else may read this thread.

Using neon testing screwdrivers can end in a nasty accident no matter how experienced or safety aware the person carrying out the test is. For example if the screwdriver becomes damaged (you won't necessarily realise) you may get a nasty shock as your using your finger to complete a live circuit. To test in this way also means a live connection will be exposed...accidentally touch it (for example you might slip on the step ladder and stick hand out to keep balance) and you'll know about!

A quick google came up with this long thread http://www.theiet.org/forums/forum/messageview.cfm?catid=205&threadid=14041&STARTPAGE=1&FTVAR_FORUMVIEWTMP=Linear that makes interesting reading on how safe (or not) these devices are and confirms what i thought that these can be dangerous to anyone including electricians.

As a DIYer i only use my neon screwdriver to double-check power is dead on circuits that i've already (or think i have already!) turned off but only after also testing light switch/socket. I have touched a live connection inside a socket before with a non-neon screwdriver and caused sparks to fly and MCB to trip - fortunately i was using a VDE electrical screwdriver which saved me getting a nasty shock - but it is not something i'd be in a hurry to repeat!

Andy

YDI_Try

Thanks Matbe,
Your advice is much appreciated - Just one final matter to clarify, are you saying that the single black switch/live wire is attached to both brown and red on the ceiling fan unit sockets ???? If so how can the single wire attach to both sockets ???

Sorry to be a bit of a derrr brain about this.

Hi Andrew B,
Thanks for your health and safety info - sicerely aprreciate your concern in this area. And as a first time user of this facility I am very pleased to have such input. In this case I don't see that there's too much risk though as although I am a complete novice in this area, practically I can't see how this is a great deal different than changing a plug, albeit bin a much more akward place- once I know which which wires go where can't see too much of a problem.

Anything more difficult and I probaly would call in the pro's

Cheers mate

andrew-b

YDI_Try wrote: »

once I know which which wires go where can't see too much of a problem.

..true but the big problem is identifying which wires goto the switch in the first place! Although matbe didn't spell it out, he is suggesting you turn the power on and touch live wires with a neon screwdriver in order to identify the switch cable - that's the part i have issue with. The rest is ok..so long as you turn the power off - as you say it's much the same as wiring a plug.

If you don't know what wire is the switched live and can't visibly follow the wires back (from loft or floor above) then the safer way is to use a digital multimeter to test (resistance test) WITH THE POWER SWITCHED OFF AT THE CONSUMER UNIT (important bit so bold!!) - you would test each black/red pair of wires without connecting them to anything and then turn switch on/off and watch what happens to the multimeter reading... whichever set completes a circuit when the switch is turned on is the pair of wires going to the switch and will show a decrease in resistance. If your unsure the "get someone in" rule applies!

However you identify the switched live you should mark it with a piece of red or brown insulating tape or a piece of red/brown sleeving for future reference.

If you remember without any doubt how the wires were connected to the previous fitting or there is red/brown tape/sleeving marking the switched live already then things become simpler! Remember to always label everything before disconnecting anything and take a picture too so you know what went where!

However i will point out that by wiring up both the light and fan (red/brown connections) to the switched live (once it's been identified) you will only be able to use the fan when the light is turned on at the switch and unless the fan has a pullcord to turn it off the fan will always be on the same time that the light is. If you were to want the fan on but not the light then the brown fan connector needs to be connected either to a permanent live (but only if the fan can be turned off via a pullcord) or to a seperate switchable live via another switch (or doubling up the existing switch).

Connecting the brown fan connection to a permanent live would be the simpler as you would just connect the two red lives to the brown fan connector (no connector blocks needed), the black wire that is the switched live would go to the red light connector, other black wire to the blue neutral connector and earths to earth connector.

To add another switch (or double up the existing switch) may become messy as it involves either routing new (two-core and earth) cable or replacing the existing switch cable with a cable with an extra wire in it (three core and earth).

Hope that helps a bit more...any doubts though get an electrician in (it might not cost as much as you think).

Andy

YDI_Try

Many thanks for the various options AndrewB - I am sure that I should be able to install the fan/light now

Cheers Mate