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https://www.askthetrades.co.uk/cgi-bin/yabb/YaBB.pl DIY Forum >> Electrical Questions >> How do I wire up my new Light Sensitive Switch? https://www.askthetrades.co.uk/cgi-bin/yabb/YaBB.pl?num=1383164839 Message started by Kitchen Foyle on Oct 30^th, 2013, 8:27pm

Title: How do I wire up my new Light Sensitive Switch?
Post by Kitchen Foyle on Oct 30^th, 2013, 8:27pm

Hi! I'm sure this will be a pretty basic query for most here but it's something I've not been able to figure out.

I purchased a Twilight Switch to activate an outside light - here it is:

www.sparksdirect.co.uk/ip55-dusk-dawn-photocell-sensor-switch-light-sensitive-timer

The wiring block inside the unit is as basic as it gets but I've tried every permutation I can think of but can't get the unit to work.

The wiring block has four terminals marked

EARTH - L - N - L1

The L (live) and N (neutral) terminals are linked and described in the diagram as 'supply 220-240V'.

The N (neutral) and the L1 terminals are linked in the diagram by a circle with an X in the centre and described as 'Load'.

Obviously, there's a live, neutral and earth coming from the mains supply and the light unit also has live, neutral and earth.

Question: How do I wire up the twilight switch between supply and light unit?

I've attempted several permuations including putting both neutrals to N and both earths to Earth and alternating the live wires between L and L1, but the unit still doesn't work. To make sure the light unit is OK I've connected it direct to the supply and it works fine - so either I'm doing something wrong, or the new switch is faulty.

Could someone put me straight as to exactly how I should wire this twilight switch correctly?

Thanks, everyone.

Title: Re: How do I wire up my new Light Sensitive Switch?
Post by Lectrician on Oct 30^th, 2013, 8:40pm

Supply neutral and load neutral to the neutral terminal.

Supply live into L.

Load (lights) live into L1.

Title: Re: How do I wire up my new Light Sensitive Switch?
Post by Kitchen Foyle on Oct 30^th, 2013, 8:58pm

Thanks for the speedy response, Lectrician.

Your instruction was the first one I tried - but when the unit failed to work I tried switching the lives and clearly that was wrong.

I'll try wiring the unit up correctly again - and if there's no joy then the unit is clearly faulty.

Thanks again, Lectrician - I appreciate your help.

Title: Re: How do I wire up my new Light Sensitive Switch?
Post by Lectrician on Oct 30^th, 2013, 9:10pm

How are you testing it? Waiting for dark, or covering it? It likely needs covering for several minutes.

Title: Re: How do I wire up my new Light Sensitive Switch?
Post by Kitchen Foyle on Oct 30^th, 2013, 9:50pm

The advice to wait several minutes for the sensor to work could be crucial. I've been covering the sensor for up to maybe two minutes maximum as I thought that would be sufficient.

So, it could be that I wasn't allowing enough time for the sensor to work.

Thanks for this extra caution, Lectrician, It may be a few days before I get time to fit the unit again but I'll certainly post an update to let you know how I get on.

Title: Re: How do I wire up my new Light Sensitive Switch?
Post by Kitchen Foyle on Nov 13^th, 2013, 9:32am

Just an update as promised in my last post.

Lectrician, the afterthought you posted with regard to the sensor delay was the key.

I wired the unit up as per your instruction (which, to be fair to myself, was the way I wired it up initially) only this time I allowed plenty of time for the sensor to work and it kicked in after around 2 minutes.

I'm reluctant to reveal a secondary mistake I made but I will, if only to advise similar caution to anyone else checking out this thread for guidance.

After fitting the sensor unit the good news is that it's working fine. However, the bad news is that the light would repeatedly come on and turn off due to me placing the sensor unit too close to the illuminated area, thus causing the sensor to react to the alternating light and dark. One of those 'Doh!' moments!

Anyways, I just wanted to express my thanks again for your valued help.

All the best to you, Lectrician.

Title: Re: How do I wire up my new Light Sensitive Switch?
Post by Lectrician on Nov 13^th, 2013, 3:06pm

Glad you sorted it - I have seen many people place the sensors where they can see the light they are switching! It's not just you! ;D