PIR floodlight - mains or lighting circuit?

[SarahLund]

Hi there,

I have bought one 400W and one 120W PIR floodlight (one for the front and one for the back). I am torn between wiring them up to the lighting circuit, or via a fused spur from the mains. Can anyone give me a definitive list of pros / cons? The downstairs lighting circuit (which I would use in both cases) has a lot of individual lights but they're all 240v low wattage LEDs - probably about 30 in total, apx 5w each.

What do you think?

I will also want to install an override switch so that I can have the lights on permanently, but that seems to be covered off pretty well in other posts.

Thanks!

 

[bernardgreen]

The 400 watt may require building regulation approval to be fitted on an external wall.

The supply choice should consider what will happen if a lamp is damaged / saturated and trips the circuit off. Connecting to the lighting circuit would leave you in darkness until you were able to isolated the damaged lamp ( fit a double pole isolator ) and reset the trip but at least you would soon know something was amiss.

Connecting to a power ( sockets ) circuit could leave appliances such as freezers without power until you realised something was wrong with the floodlights.

 

[SarahLund]

Thanks bernardgreen, very helpful. I don't suppose that putting a 3A fuse in the FCU would get around the issue you identified?

Does anyone have a diagram I could use for wiring up an override switch? Ta

 

[SarahLund]

Thanks bernardgreen, very helpful. I don't suppose that putting a 3A fuse in the FCU would get around the issue you identified?

Does anyone have a diagram I could use for wiring up an override switch? Ta

 

[PrenticeBoyofDerry]

A FCU would provide double pole isolation.

As regards to override wiring what make and model of light have you purchase? most these days have built in override function.

 

[SarahLund]

They're cheapo ones from a shed whose name starts with W. Cost me a tenner each. I didn't see anything in the instructions about an override function, but it may be possible. Thinking about wiring up an override switch in any case, just can't work out how...

 

[PrenticeBoyofDerry]

If it is the Shed I am thinking of, I believe these lights are going to malfunction on you very shortly and you will not need an override switch as they will be permanently on!
Best advice I can offer is return them and buy a quality product, they don't cost a fortune to buy.

 

[SarahLund]

You are probably right. But what if I still wanted to install such a switch on the offchance that they do work?

 

[PrenticeBoyofDerry]

L, N and Earth/CPC from FCU to switch. then 3 core and earth to PIR.
Brown is perm L to PIR, black from switch to PIR out. grey N sleeved blue, then L and N from PIR to light.
All earths/CPCs to earth terminals.

 

[SarahLund]

Excellent, thanks - will give this a try!

 

[bernardgreen]

This is the circuit

PIR with overrides

• bernardgreen
• 18 Mar 2011
• 20

Using two single pole switches to provide overrides for a basic PIR

The 3 amp fuse would protect only against overloads. The most common problem with external lamps is earth leakage due to dampness from Live and / or Neutral and this trips the RCU. it will not blow a 3 amp fuse

 

[winston1]

Hi there,

I have bought one 400W and one 120W PIR floodlight (one for the front and one for the back). I am torn between wiring them up to the lighting circuit, or via a fused spur from the mains. Can anyone give me a definitive list of pros / cons? The downstairs lighting circuit (which I would use in both cases) has a lot of individual lights but they're all 240v low wattage LEDs - probably about 30 in total, apx 5w each.

What do you think?

I think you should return them and get LED ones which use a lot less power.

 

[ericmark]

It was a 150W limit without planning permission. Not sure if this has changed to lumen value?

 

[Tipper]

We were going to fit mains powered flood lights around our bungalow but couldn't decide what type...then found these which work brilliantly and no wiring to do!

http://www.thesolarcentre.co.uk/products/ECO_Wedge_Solar_Motion_Welcome_Light-739-78.html

(I've no connection with The Solar Centre other than being a very satisfied customer.)

 

[ban-all-sheds]

How long have you had them?