Fan controller turning on with ANY item in the house(s)

[Malakym]

I have a Vents TH1.5N, its a fan controller that has a run on timer and humidity sensor.

It works, with regards to time and humidity as expected.

But what happens is whenever another item in the house, no matter which circuit is turned on, the controller starts the fan.


This was initially installed by an electrician in new house wiring, we put it on another circuit and the same. I returned home and tried it... same again. Contacted retailler who sent me a new one.... same again.

It has L, N and LT(switched live) in and works as expected when you use LT as switched. The output only has 2 poles for the fan and the fan works.

If we got L and LT confused, it would just turn off as soon as the light/switched live was off right?


Any idea whats up? I've tried them both in two different houses with the
same issue!

 

[EFLImpudence]

I would say it's faulty.

Disconnect the switched live and see if it still does it.

Have you given the correct model number?

Googling leads to boilers.

If we got L and LT confused, it would just turn off as soon as the light/switched live was off right?

Yes.

 

[Malakym]

There are multiple model numbers depending on what it does, Timer, Humidity, Photosensor and Infrared etc

This is the model... (although picture is different).
http://www.ventilation-system.com/cat/242/


It is possible that both are faulty, although I wanted to check with more people before going back to the retailer as they might assume im doing something wrong.


I've already tried it without switched live, thats how I test it at the other house (basically wire it up to a plug).

 

[EFLImpudence]

What I meant was disconnect the switched live and see if it still comes on when you switch on other things.

If you have it wired properly and it doesn't work properly then it's faulty.

Did the shop assistant seem as if they were used to them being returned?

 

[Malakym]

The item was purchased online.

It still comes on when switched live is disconnected...

 

[Mursal]

is there an earth point in the timer?

 

[Malakym]

No earth...

 

[sparkybird]

i had something similar with a couple of these fans in 2 different installs:

http://www.tlc-direct.co.uk/Products/ADAUE100T.html

when any light on the circuit was switched on, the fan came on.

I ditched the fans and installed different brands - all OK. I suggest trying a different make of fan and see what happens

BTW Airflow were not interested in my complaint!

 

[Malakym]

I don't think the model of fan matters as the problem occurs even when the fan isn't wired up (I can use the status light to see what the controller is doing).

 

[JohnW2]

i had something similar with a couple of these fans in 2 different installs: ... when any light on the circuit was switched on, the fan came on. I ditched the fans and installed different brands - all OK.

The design of many of the electronic timer modules is such that it takes remarkably little to 'trigger' them - I would suspect that capacitive or inductive coupling from nearby cables could sometimes be enough to result in the behaviour that is being described. I've had fans being triggered by nearby lightning.

Kind Regards, John.

 

[JohnW2]

I don't think the model of fan matters as the problem occurs even when the fan isn't wired up (I can use the status light to see what the controller is doing).

In your case it won't matter since, as I understand it, the timer is in your controller, not the fan. Sparkybird was talking about fans with built-in timer modules.

Kind Regards, John

 

[TicklyT]

Do you have a low energy lamp in the light fitting wired to the fan controller switched live?

The switched live could be left floating at an indeterminate voltage by the high impedance electronics inside a low energy lamp, and that voltage may rise or fall as other appliances in the house are switched on, triggering the fan.

With a conventional filament lamp in the fitting, the switched live would be clamped at or close to the neutral potential by the resistance of the lamp filament until the light is turned on.

 

[Malakym]

Yes, in its intended position its working with a low powered bulb. Although when testing on another circuit (Basically a plug into a standard socket) with the lights and etc off it does the same.

Same when its used in another house, this house also uses low energy bulbs in some rooms but has been checked in the day when the lights have been off.


The idea that the bulb was an issue did come up, hence why we tested without.

 

[TicklyT]

Have you tried with a conventional filament lamp installed in the fitting?

Just removing the low energy lamp and leaving the lamp holder empty will not clamp down any transient voltages appearing on the switched live in the way that a filament lamp does.

 

[Malakym]

I will give that a try when I can. But I am not sure it will do much different than running it at another property which has a mix of both types installed.

Thanks for all the replies so far - will take me a day or so before I can test it in situ.