Problem Fan Question SparkyTim

[sparkytim]

I think we need to rename this thread;

Problem of the 3 weeks

Are we ready for another?

I have a few basic ones for our newer members to the fraternity, such as

New Duct fan installed in a loft for bathroom extraction wired in with light so over run timer triggered by light. Fan Non functional.

Installation details.

Fused connection Unit (FCU) fitted in loft adjacent to fan, 1mm T&E feeding it from the lighting circuit, T&E from load side of FCU to bathroom light via pull switch, sgle core switch wire back from light switch to FCU, 3 core from FCU to fan, all connected correctly. FCU isolates light and fan.

First question, what basic tests should be performed, (results of the real testing carried out yesterday on this will be given on request)

 

[ProDave]

Sparkytim, you gazumped me. My "problem" will have to wait now.

Usually when a timer fan does not work, it's because you have L and SWL the wrong way round in the fan.

 

[sparkytim]

Sorry Dave, hope this one should be sussed quickly.

All connections correct at FCU, fan, light and pull switch.

Any newer guys in the game want to play?

 

[NozSpark]

Is the fan non functional or just not doing what you expect it to?

 

[sparkytim]

No function at all

 

[NozSpark]

Ooooooooh

 

[sparkytim]

??

All other lights on the circuit function.

 

[steptoe]

I left my pencil in the blades?

fan tightened too much on the wall?

---------- Post Auto-Merged at 20:11 ---------- Previous post was made at 20:10 ----------

or the best one Ive seen yet, an ELV fan wired straight to 230v, when I pointed this out he installed a new ELV fan and wired the Tx the wrong way round!

 

[NozSpark]

And Tim said that it's a new fan so it isn't yet filled with talc, skin cells and mould

 

[sparkytim]

230 volt fan blades free to turn

 

[springcrocus]

??All other lights on the circuit function.

But does the bathroom light work?

 

[NozSpark]

I had one of these the other week...

Replaced a fan, tested it and it was ok

Phone call the next day, fans not working when they're in the shower,, so as it's only down the road I pop down to have a look......

You do know the fan comes on with the lights don't you??

 

[sparkytim]

Not handed it over to user yet, and yes light is working in bathroom but to be fare it should have not been IF wiring was as it appeared to be.

More info to help;

Exiisting circuit is T&E looped into 3 plate ceiling rose, bathroom light is end of line and instructions to installer were to identify cable feeding bathroom and fit FCU to isolate bathroom and wire in fan from it.

 

[ProDave]

Not handed it over to user yet, and yes light is working in bathroom but to be fare it should have not been IF wiring was as it appeared to be.More info to help;

Exiisting circuit is T&E looped into 3 plate ceiling rose, bathroom light is end of line and instructions to installer were to identify cable feeding bathroom and fit FCU to isolate bathroom and wire in fan from it.

Right.

The installer got it wrong, and took the feed from the switched live in the original ceiling rose.

Presumably the original switch drop is now disconnected and a new switch drop comes from your FCU

And the old switch drop is still there, but going nowhere, and capacitance between the cores enables a low energy light to light, just, but not enough power to work the fan.

Checks you should make:

Measure voltage feeding IN to FCU both with light switch on and light switch off.

Measure voltage coming out of FCU both with light switch on and light switch off.

Check there is a fuse in the FCU and it's a good fuse.

 

[sparkytim]

Ok

Fuse tested OK

Voltage measured at FCU IN AND OUT

L-N 0 Volts

L- CPC 230 V

N-CPC 230 V

Existing supply to bathroom was broken into on route from previous rose to feed into FCU and out to existing bathroom pull switch and onto light. (Supposedly)

 

[ProDave]

Someone messed up and the neutral did NOT get connected then. you have a floating neutral.

Either that, or what they THOUGHT was a live feed that they "broke in to" was in fact a switch drop to another light.

Trace it back until you find somewhere where L-N DOES read 230V then fix the break / bad connection.

 

[Guy]

I haven't even got my pencils out yet.

 

[sparkytim]

Someone messed up and the neutral did NOT get connected then. you have a floating neutral.Either that, or what they THOUGHT was a live feed that they "broke in to" was in fact a switch drop to another light.

Trace it back until you find somewhere where L-N DOES read 230V then fix the break / bad connection.

Correct, give that man a biscuit.

What the installer thought was the feed from rose to bathroom was in fact the switch wire for the bedroom.

Duely slapped and instructed to do better next time.

JB fitted to repair Switch wire and correct cable broken into, job sorted.

So its over to you then Dave.

 

[Doc Hudson]

Posts moved onto a new thread from the original Problem of the week thread. this should make it easier for others to find the beginning of a problem and comment or ask further questions about an earlier problem.

Doc H.

 

[steptoe]

OkFuse tested OK

Voltage measured at FCU IN AND OUT

L-N 0 Volts

L- CPC 230 V

CPC- N 230 V

Existing supply to bathroom was broken into on route from previous rose to feed into FCU and out to existing bathroom pull switch and onto light. (Supposedly)

can I just point out that that is an impossibility,

Im sure the poster means the best, but simple things like this can mean an awful lot in our trade,

please always put the flow point first,

ie, on a normal install you would never put cpc-L 230 N-L 230,

I hope you understand where Im coming from here.