Electrical interference/leakage

[James94]

Hi all,

I have had an electrician come and change how a bathroom inline fan is controlled and when they had gone I noticed two of the four bathroom led lights are on constantly, very dim. If I turn them on and off and dimmer them they work fine but when off stay dim.

I'll give you a little background to what he's done. The fan was originally on a switch and he's changed how it works by installing a manrose 1361 remote bathroom fan humidity control with timer. He's also added a fan isolator in loft and he's connected it to the new fan which was in loft  manrose mf100t.

So, I've had him back and he thought he sorted it but same when they'd gone it was back the same two dim lights. He's now saying that it's because of the set up and the type of fan installed he's saying we need to buy a new fan that doesn't have an over run, is he correct?

Regards james

[Nickfromwales]

If they’re cheap leds then you may need a snubber (capacitor) across the feed to the lights. 
 

Do the leds only glow when the fan is running, and then go out when the overrun time has elapsed? 

 

Manrose is industry standard stuff btw, so it’s not like it’s made from Ali Express chinesium or worse. 

[James94]

Hi Nick,

there gu10 led bulbs from Screwfix, so not sure about cheapness.

he has mentioned about a capacitor but i don’t really understand it to much.

It’s only started since he’s fitted the humidity sensor, is this what’s causing it as fan is original?

 Im not sure what leds do when running as usually in shower when it comes on 😛 and light usually switched on. But when lights switched off the stay dim.

Is there any tests I can carry out to see what’s going on?

do I need to buy a new fan like electricians said as the one in is new, he says I need fan without overrun built in? Would this cure it?

Regards. James

 

[Nickfromwales]

I think we have found the problem! 
 

Just re-read your first post….

 

21 hours ago, James94 said:

If I turn them on and off and dimmer them they work fine but when off stay dim

Are you saying you have a dimmer switch controlling these lights? If so that needs to go, and the sparky should have told you this. LED dimming causes all sorts of grief, plus you can’t control fans or timers with a variable voltage input such as a dimmer. 
 

Afaic, this needs to be a regular switch, so if you can, change that over and test it again. 

 

 

@James94 also, you need the overrun for when someone’s used the loo, so there’s no reason why these two functions should be working without issue. 

[James94]

Hi Nick,

can’t seem to get my head around what your saying, I’ve always had them on a dimmer switch and had no issues. The humidity sensor and fan are totally separate to the lights, this is why I can’t get my head round why it’s effects the lights. 
I will put a normal switch on and see if it makes any difference but electrician didn’t say owt about that.just said I need new fan.

I’m not bothered about when someone has been to loo, it’s just through the humidity sensor when it comes on. I think this is why  the electrician has said I don’t need a fan with an over run as the fan is powered up until no moisture is sensed,am I wrong in thinking this?

Regards. James

[Nickfromwales]

1 minute ago, James94 said:

Hi Nick,

can’t seem to get my head around what your saying, I’ve always had them on a dimmer switch and had no issues. The humidity sensor and fan are totally separate to the lights, this is why I can’t get my head round why it’s effects the lights. 
I will put a normal switch on and see if it makes any difference but electrician didn’t say owt about that.just said I need new fan.

I’m not bothered about when someone has been to loo, it’s just through the humidity sensor when it comes on. I think this is why  the electrician has said I don’t need a fan with an over run as the fan is powered up until no moisture is sensed,am I wrong in thinking this?

Regards. James

So you have a separate switch for lights, that doesn’t provoke the fan to come on at all? 
 

And a second switch to trigger the fan to start and overrun. 
 

And the humidity stat is permanently powered and switches on / off of its own free will?

[James94]

Hi Nick
 

So you have a separate switch for lights, that doesn’t provoke the fan to come on at all? 
yes

[James94]

Hi Nick

And a second switch to trigger the fan to start and overrun. 

no the humidity sensor powers the fan until no humidity sensed then turns off, I think that’s how sensor works.

[Nickfromwales]

FYI, if you click on text in a post and highlight it, you’ll see a pop up saying “quote selection”. 
 

To ‘mention’ a member, type @ and the first letter of their username and select from the drop down list   

[James94]

Hi Nick

 

And the humidity stat is permanently powered and switches on / off of its own free will?

powered by humidity sensor and goes off when no humidity, I think that’s how it works.

Regards. James

 

[James94]

Just now, Nickfromwales said:

FYI, if you click on text in a post and highlight it, you’ll see a pop up saying “quote selection”. 
 

To ‘mention’ a member, type @ and the first letter of their username and select from the drop down list   

😛 

[Nickfromwales]

1 minute ago, James94 said:

Hi Nick

And a second switch to trigger the fan to start and overrun. 

no the humidity sensor powers the fan until no humidity sensed then turns off, I think that’s how sensor works.

Yes, got that, thanks.

 

I meant that the spark wired to humidistat to be on 24/7, so is likely to just be on the loop in and not connected to the lights. 
 

This means the culprit seems to be the fan.

 

I'd contact the manufacturer and ask if they can provide a snubber and give details of where it should be connected to rid you of the issue.

 

At least this should discount the dimmer / light switching. 

[James94]

Thanks for all your help Nick,

I will try and get in touch manrose tomorrow and try and explain what’s going on and see if they can recommend a solution.

Regards James

[Nickfromwales]

1 hour ago, James94 said:

Thanks for all your help Nick,

I will try and get in touch manrose tomorrow and try and explain what’s going on and see if they can recommend a solution.

Regards James

Cool. Just better to not void the warranty of your new equipment, so see if they have a product to give you. 

[BotusBuild]

IF the humidity sensor gets its power from the lighting circuit, the sensor, the fan and the dimmer switch are now all electrically connected.

The combination of the electronics in the sensor (the NEW item in the circuit), the fan and the dimmer switch may be causing interference along those electrical connections causing a trace current to exist causing the LEDs to glow dimly. Seen this before and it was an elimination exercise to get rid of it. As @Nickfromwales has said try the switch change (the simple cheap first step). After that it's back to the electrician and check what circuit that sensor is connected to.

 

It may have been a better idea to change the fan to one with an integrated humidity sensor e.g.

https://www.powerdiscount.co.uk/greenwood-unity-cv2gip-smart-dmev-extractor-fan-with-timerhumidistat-764-p.asp?msclkid=fcf8825d4a5e11a8765eeb2b0f8bd0b6