Manrose MF 100 extractor fan

[foxhole]

Always found the Manrose fans poor quality and unreliable, unlikely to be any better than what you replaced.

Mileage obviously varies. I've nearly always used Manrose fans, and most have been perfectly reliable and have lasted for very many years. If you don't like Manrose ones, which make do you favour?

Kind Regards, John

Fitted 6 units one lasted a week and another only 4 weeks.

 

[mrpip]

Hi all, thanks for your replies, I haven't fitted it yet but will let you know how I get on.

 

[mrpip]

Back again, doing fan tomoz. Please confirm mains L, mains N and mains E all to be made safe and use switch L and N to operate fuse switch and fan unit. Sorry to make a big fuss about a little job but as I have never done anything other than 'like for like' jobs before I want to ensure all is good.

 

[EFLImpudence]

Yes, do this:
Your colours may be another way round or
Red, Yellow, and Blue. Check which is which first.

 

[mrpip]

Thank you so much for your help EFLImpudence, so the leads coming from the light into the fuse switch are all from the switch live which at the moment is made up of live only with the neutral cut back, I have to trim switch cable and connect to allocated points and block off the mains cable safely and use only the switch cable?

Sorry to come across a bit thick but I only want to do it once and make sure it's right.

 

[mrpip]

Hello again, I know I have aimed my last question (in post above)at EFLImpudence but if any body could confirm what I have asked him is correct it would be much appreciated.

Thank you

 

[EFLImpudence]

so the leads coming from the light into the fuse switch are all from the switch live which at the moment is made up of live only with the neutral cut back, I have to trim switch cable and connect to allocated points and block off the mains cable safely and use only the switch cable?

Well, that depends.

The single cable is more likely to have been added when someone previously fitted the timer fan (instead of one like you have now bought).
You will have to determine which wire does what.

Do all the wires come from the light rose?

 

[mrpip]

Oh blimey, would be so kind as to let me have a good mooch in the morning and find where the connections are and I will get back you you? If not then could you give me all the wiring variations and I could use the appropriate option?

Thanks again

 

[mrpip]

Good morning, I've had a look and the single, L+cut N, is fed from the ceiling rose and the 3 core wire from the switch

 

[mrpip]

If any body else is available to help out, please, feel free.

 

[oldbutnotdead]

Your old fan had 2 lives (1 switched and 1 permanent), a neutral and an earth. Your new fan only needs switched live, neutral and earth.

The single live from the light fitting might be the switched live- or it might be the permanent live, depends how the lighting has been wired. Fortunately you only have 2 options- the live you already tried and the other live. Safely terminate the live you already tried (terminal block in the pattress box or fan is fine), connect the other live to the fan.

Test for function.

The 'fused switch' you refer to needs to be in the circuit to protect the skinny cable inside the fan (which will only be 0.5mm or less). I reckon you'll have put the FCU in the permanent live rather than the switched live so you'll need to rectify that.

You should also have an isolator local to the fan (so that the fan can be isolated from the supply for maintenance without knocking the lighting circuit off at the CU). This isolator needs to be a 3 pole type (so that BOTH lives are disconnected).

 

[EFLImpudence]

Good morning, I've had a look and the single, L+cut N, is fed from the ceiling rose and the 3 core wire from the switch

That would seem to confirm what I said but obviously cannot be certain.
I do not know the routes of the cables.


Why don't you do it the other way round?

Get the fan working as it should by connecting the Neutral and Switched Live.
Then you will know which wires are which at the other end of the cable(s).

Insert the Fused Switch to the relevant conductors.
Possibly swapping the wires if more convenient.

 

[EFLImpudence]

I reckon you'll have put the FCU in the permanent live rather than the switched live so you'll need to rectify that.

The permanent live will no longer be needed so can be disconnected or ignored.

You should also have an isolator local to the fan (so that the fan can be isolated from the supply for maintenance without knocking the lighting circuit off at the CU).

The fused switch will do for this and there won't be a permanent live connected to it.

This isolator needs to be a 3 pole type (so that BOTH lives are disconnected).

As above.
It would be silly to fit a three pole switch because there is a conductor which is no longer required.

 

[JohnW2]

It would be silly to fit a three pole switch because there is a conductor which is no longer required.

That is true with the OP's new fan. However, most people seem to favour timer fans, so when it next gets replaced (maybe by a new occupant), that third conductor might be required - so it might be 'kind' to fit a three-pole switch/isolator now!

Kind Regards, John

 

[oldbutnotdead]

And I personally wouldn't like the isolation being in the loft (there's an earlier post saying the new FCU is up there)- yes in a domestic setup the risk is low but it isn't big or clever.

The 3 pole isolator was just to make the job easier- yes the permanent live is redundant and could/should be disconnected at source but (a) not going to happen (b) keeps options open for future replacements