Another humidistat extractor fan question

[ercole89]

Hi, I realise there was a similar question earlier this week but my problem is slightly different. I'm not an expert/electrician so go easy on me if I say something stupid!

I have an Xpelair C6HTS humidistat+timer fan which replaced a simple on/off pull switch operated fan (not connected to the bathroom light). The new one is supposed to come on when humidity rises above a certain level, then once below that threshold it runs on a timer for e.g. 30 more seconds.

The problem we are having is that once the fan is activated it does not stop. We left it all night last night with the humidistat unplugged and it went until the morning. When we reset it at the fuse box, it finally stopped, presumably until triggered again by the humidistat (once plugged back in).

Tech support are saying it requires a 3-core and that's why it isn't stopping. There's only a live and neutral there. Are they right? I thought having a 3-core would just allow us to put a switch on it too. We're happy for it to work just on the humidistat without a switch if possible.

Is there any way around this? Trying to avoid running a new wire in as the two that are there go into the room next door (or possibly the loft) rather than off the bathroom light circuit.

 

[EFLImpudence]

If you wire the L & N to the correct terminals - Permanent Live and Neutral - leaving the Switched Live/Timer terminal empty, it should work on just the humidistat.

If you connect the PL wire to SL terminal and leave PL terminal empty, it shouldn't come on at all.
If you connect the PL wire to SL and PL, it will run for ever.

So, what you say shouldn't happen.


You are right about 3core and Switch.

 

[ercole89]

Thanks for the quick response! It was installed by an electrician, who presumably knew what he was doing. So we need PL connected to PL terminal, and N connected to the N terminal, and nothing else wired up, and it should work as specified? I'll check what we've got tomorrow. It frustrates me when tech support give you the wrong answer.. he sounded so sure and since I wasn't 100% I just gave up arguing. Maybe didn't help that it was 4.30pm on a Friday, he probably wanted to go home!

 

[EFLImpudence]

Thanks for the quick response! It was installed by an electrician, who presumably knew what he was doing. So we need PL connected to PL terminal, and N connected to the N terminal, and nothing else wired up, and it should work as specified?

Yes.

I'll check what we've got tomorrow. It frustrates me when tech support give you the wrong answer.. he sounded so sure and since I wasn't 100% I just gave up arguing. Maybe didn't help that it was 4.30pm on a Friday, he probably wanted to go home!

 

[ercole89]

Hmm, the wires are going into the right boxes. I was hoping it would be an easy fix but it seems something else is going on.

IMAG6013

• ercole89
• 29 Sep 2017

Customer connection terminal

The wiring instructions are below and there is also a paragraph that specifies 3-core in the written instructions, but again I think that's just to allow a switch. Would you think the requirement for the switch and the 3-core actually makes any difference to the fan operation if there is no switch? Would it be possible that there's an issue with our power supply or something, constantly triggering it?

IMAG6014

• ercole89
• 29 Sep 2017

 

[EFLImpudence]

Whilst it compares to the diagram.

What letters are under the wires?
LINE means the live wire; that looks like the wires should be the other way round.

 

[Taylortwocities]

Really?? It looks like brown in L and blue in N

 

[EFLImpudence]

That was quick TTC. I was going by LINE

 

[ercole89]

No they're the right way round, TNEL as on the instructions. Better pic here (if a bit dark)

IMAG6015

• ercole89
• 29 Sep 2017

 

[EFLImpudence]

Oh, that's a pity.

Well, it LOOKS alright, then.



Also, it looks like it should have an earth. I wouldn't think that is anything to do with the problem.

 

[ercole89]

Hmm. Well, thank you for your help. Maybe something in the circuit board is broken. I'll do some more googling tomorrow, for now goodnight!

 

[ercole89]

Another piece of the puzzle. Today plugged the humidistat back in and it started straight away, which was good because I was about to have a shower. Post-shower, most of the steam gone, I unplugged the humidistat again. The fan stopped straight away whereas the other day it carried on all night. Any ideas?

 

[ercole89]

Here's what it looks like. The humidistat is attached to the blue cable on the left. The humidistat potentiometer is the blue cylinder on the left, the timer potentiometer is the one on the right. The timer is set to its minimum of 30s, so theoretically I think it should run for 30s after the humidistat is unplugged, but it either stops straight away or carries on forever.

 

[flameport]

Any ideas?

Humidity sensors are generally useless, and to get any kind of intended operation out of them requires hours of adjustment to get to whatever a usable setting is.
Repeat after a month as humidity levels change depending on the weather, time of year and so on.

 

[ercole89]

Thanks flameport - we were expecting to have to do some adjustment but this thing isn't functioning as expected at all. I'm pretty sure if the humidistat is unplugged ie no longer triggered it should stop after 30s, not either stop straight away or carry on forever. Wondering if tech support was right about needing 3 core although can't understand how that would work.