Replace normal switch with pir switch

[jpank]

Hi all. I'm looking to replace a normal light switch with a pir switch on my downstairs WC, which also has an extractor fan that comes on with the light.

This is the switch I found and attached are the pictures of the current install.

Can it be done?

Motion Sensor Switch with Occupancy Sensor/Vacancy Sensor/On-Off Switch,Pir Motion Sensor Light Switch with Time Delay&LUX Setting Adjustable,5A,AC110~265V,PC Fireproof(Neutral Wire Required) https://amzn.eu/d/5XIXd01

 

[flameport]

Yes it can be done.

3 brown in COM are permanent line
Brown and black in L1 are switched line
The blue wires in the separate connector are neutral.

Buying electrical items direct from China via Amazon is not recommended.

 

[jpank]

Thanks @flameport.

I'll keep looking to see if I can find a similar product that's not from China.

 

[ericmark]

It seems the switches are available local this link shows one however not sure if it helps. The problem is knowing which can work a fan with the back EMF without damage to the switch.

Also in a toilet not sure a PIR is appropriate, I know it called a movement but that type of movement will not activate a PIR.

 

[jpank]

@ericmark the problem I'm trying to solve is that the light is constantly left on. Any other suggestions?

 

[ebee]

It might be possible to separate the L`s and the N`s for the extractor and for the light.
Therefore you could have a PIR switch for the light only and a manual switch for the fan only

 

[Taylortwocities]

I have one in my downstairs wc. For exactly the same reason (light always being left on)
I just need to wave my hand if I sit too long!

Hint. For small room
Set PIR time for 10mins. Set fan timer to minimum.

 

[jpank]

I have one in my downstairs wc. For exactly the same reason (light always being left on)
I just need to wave my hand if I sit too long!

Hint. For small room
Set PIR time for 10mins. Set fan timer to minimum.

@Taylortwocities which switch did you install?

 

[Taylortwocities]

@Taylortwocities which switch did you install?

https://www.amazon.co.uk/gp/product/B009YW6UO0/ref=ppx_yo_dt_b_search_asin_title?ie=UTF8&psc=1

The switch allows you to have the light on permanently (while you do your eyelashes) or on automatic PIR mode.

 

[SUNRAY]

It seems the switches are available local this link shows one however not sure if it helps. The problem is knowing which can work a fan with the back EMF without damage to the switch.

Why is this an issue?
Unless something unusual is being done with the way it's wired the back EMF doesn't have a path outside the fan or it's 'snubbed' by the whole of the DNO's network.

 

[Taylortwocities]

Why is this an issue?
Unless something unusual is being done with the way it's wired the back EMF doesn't have a path outside the fan or it's 'snubbed' by the whole of the DNO's network.

Eric always like to throw in a curved ball. In a while we'll get a 55,000 word dissertation on back EMF.

 

[SUNRAY]

Eric always like to throw in a curved ball.

However this wouldn't have been randomly plucked out of the air, I imagine it has been a problem at some stage, I problem I struggle to invisage without incorrectly wired.

In a while we'll get a 55,000 word dissertation on back EMF.

 

[jpank]

https://www.amazon.co.uk/gp/product/B009YW6UO0/ref=ppx_yo_dt_b_search_asin_title?ie=UTF8&psc=1

The switch allows you to have the light on permanently (while you do your eyelashes) or on automatic PIR mode.

What's your view on installing ceiling mounted pir between the switch and light (instead of the pir switch)?

 

[Taylortwocities]

What's your view on installing ceiling mounted pir between the switch and light (instead of the pir switch)?

It depends on the wiring. Looking at the switch, you may not have all the connections that you need at the light. You’ll need a perm live, switched live and neutral. The fan will have those connections but you may need to do some configuration of cables.

 

[jpank]

It depends on the wiring. Looking at the switch, you may not have all the connections that you need at the light. You’ll need a perm live, switched live and neutral. The fan will have those connections but you may need to do some configuration of cables.

Sounds like I'd have to get someone in to do that. I'm thinking I'll try the switch you've suggested first.