bathroom extractor fan installation - query

[isaact4569]

Hi,

I'm looking to install a new bathroom extractor fan in my bathroom as I have a windowless bathroom and the current one I have installed in bathroom ceiling is just a standard one and isn't powerful enough so looking to change this to a Manrose MF100t inline extractor fan.

Attached photos of the Hager J804 4 way terminal maintenance free box and also image of current existing wiring in current extractor fan. I have the 3 core and earth 1.5mm.

Looking at the current wiring in current fan, we have red, blue yellow and black wire.

The 3 core and earth cable have 4 wires - grey, black, brown and a bare wire without sleeve.

Just wanted to check, looking at the terminal box we have 4 terminal blocks with each block have 2 ports (not sure why).

Would this work as follows:

N - blue existing wire (one end) , grey wire oppostite end

Not 100% sure but 2nd terminal block appears to be for earth - yellow existing wire (one end), bare wire with a yellow / green sleeve on other end

L1 - red existing wire one end , brown wire opposite end

L2 - I am unclear on this one. We have black wire currenting exisiting and on new 3 core and earth. Would these connect together?

Also does anyone know why 2 ports per terminal block?

 

[Murdochcat]

In your existing cable has the CPC been cut so short you can't see it?

Can you get to the other "end" of the existing cable?

 

[EFLImpudence]

Also does anyone know why 2 ports per terminal block?

Actually four ports with the two at the other end.

So that four wires can be connected together.

 

[isaact4569]

I can get to the other cable yes, which is running from the ceiling light. Not sure of the CPC. what does CPC refer to?

For this job, would a terminal junction box work or unlikely?

 

[isaact4569]

I can see 8 ports, 2 ports per terminal block, 4 terminal blocks. One side. The other side also appears to have 8 ports, 2 ports per terminal block but 4 overall blocks.

 

[EFLImpudence]

Circuit Protective Conductor - Earth wire.

 

[EFLImpudence]

I can see 8 ports, 2 ports per terminal block, 4 terminal blocks. One side. The other side also appears to have 8 ports, 2 ports per terminal block but 4 overall blocks.

There are four terminal blocks, each with four ports; two each end so sixteen ports altogether.

 

[EFLImpudence]

N - blue existing wire (one end) , grey wire oppostite end

Yes.

Not 100% sure but 2nd terminal block appears to be for earth - yellow existing wire (one end), bare wire with a yellow / green sleeve on other end

Yes.

L1 - red existing wire one end , brown wire opposite end

Yes.

L2 - I am unclear on this one. We have black wire currenting exisiting and on new 3 core and earth. Would these connect together?

No you don't. There is no black wire in the red, yellow, blue cable.

Yellow one end, black (from brown, black, grey cable) opposite end.

 

[isaact4569]

Circuit Protective Conductor - Earth wire.

I originally thought the yellow existing wire was earth but I believe this is wrong as this is switched live which runs the current fan w/timer? I can't seem to find any earth wire either.

 

[EFLImpudence]

As mentioned above it must have been cut from the cable at the fan end but no matter it isn't required anyway.

 

[isaact4569]

Yes.


Yes.


Yes.


No you don't. There is no black wire in the red, yellow, blue cable.

Yellow one end, black (from brown, black, grey cable) opposite end.

Thanks. We have two yellows now. I thought I didn't have earth wire.

2nd terminal block appears to be for earth - yellow existing wire (one end), bare wire with a yellow / green sleeve on other end to connect you said yes but then you mentioned for L2 port - Yellow one end, black (from brown, black, grey cable) opposite end.

Theres only just the one yellow wire from existing.

In existing connection in fan, two black wires running into a seperate block. What happens to this? Does this still go in the 4 way hager terminal box or does this wire need to be terminated?

 

[EFLImpudence]

Thanks. We have two yellows now. I thought I didn't have earth wire.

The yellow is nothing to do with earth.
The earth wires are the bare ones which might have green&yellow sleeves.

2nd terminal block appears to be for earth

Yes.

- yellow existing wire (one end),

NO

bare wire with a yellow / green sleeve on other end to connect you said yes

Ignore the sleeving - a bare wire both ends.

but then you mentioned for L2 port - Yellow one end, black (from brown, black, grey cable) opposite end.

That's right.

Theres only just the one yellow wire from existing.

Yes, I know.

In existing connection in fan, two black wires running into a seperate block. What happens to this?

Nothing. Leave it - that is the wires to the motor.
They are not connected to your cable

Does this still go in the 4 way hager terminal box or does this wire need to be terminated?

I don't understand.

 

[ericmark]

I would go back to basic first, why do you need a more powerful fan? My shower room the extractor has failed, and since we have no problems done nothing to correct it.

I have looked at three houses and their shower rooms, two no problem, one mould growth, and it is nothing to do with the bad house being just outside Mold.

It is all down to the chimney effect. The house with the problem the shower is over the bath, so the shower doors can't seal either top or bottom, and the floor is not tanked, so it needs doors around the shower, so air goes in below the door over bath, and out above it meaning the whole room gets damp.

The other two houses, one was a wet room so no doors or curtain around the shower, the other the doors seal at the bottom, so in both cases no chimney effect, all water retained local to shower. Whole room does not get wet.

The other problem is where and when the air is drawn from the shower, with the vent above the shower again stops air circulating around the room, however it can be darn cold, so really want the extractor to run when we have finished showering not while having a shower, and the replacement air needs to come from some where dry.

This house humidity is around the 50% in fact 38% today, the house with a problem, rare would see humidity under 70% not talking about the shower, but the rooms the shower extractor is dragging the replacement air from. The shower room needs to be hotter than the room taking the replacement air from. Best is get replacement air from outside.

My first house was very dry, has gas hot air central heating, and would place trays of water in the air intake to try and make house damper, plants are good at lifting the humidity, or bad at getting humidity too high if house already too humid. Windows are a big problem, we would have metal frames for the windows and a catchment tray to lead the condensate outside with the old single glazed windows, as double glazing came in we also got central heating, so ventilation and moisture did not go through the roof as with solid fuel heating, but the moisture was allowed to build up, today vents are built into windows, but early double glazing tried to seal the house.

 

[EFLImpudence]

 

[isaact4569]

The yellow is nothing to do with earth.
The earth wires are the bare ones which might have green&yellow sleeves.


Yes.


NO

Ignore the sleeving - a bare wire both ends.


That's right.

Yes, I know.


Nothing. Leave it - that is the wires to the motor.
They are not connected to your cable


I don't understand.

Many thanks.

The last part was in reference to the two black wires but you answered this here in that they relate to the motor. All clear now. In other words just to add so the bare earth wire in the 3 core and earth (new) we do nothing with this as I have no earth in existing so we leave as is in the new 3 core and earth cable, doesnt require stripping.