photocell

[thomo27]

evening all

I replaced a 5 foot lampost in a car park recently..the car park consisted of 9 lights broken down into 3 circuits all lights switched by a single photocell..before digging out the old post I covered photocell and knocked off mcbs 1 at a time to know what lights were on what circuit and have an idea of which direction the cables may run..on covering photocell I found only 1 lamp working I checked voltage on all other posts and found 240v l-n and l-e on supply side..all fuses fine too..drove past tonight 8pm and all on..any thoughts please

 

[RF Lighting]

I'm assuming This is a private carpark at a supermarket or similar?

Sounds like originally the photocell via a contactor brought the lights straight on. This is a fairly normal setup for private car parks.


Perhaps the heads on some of the columns have been replaced at some time and the new heads have integral photocells?

 

[thomo27]

yes its a doctors car park

the lights are all the same from when our firm installed them 8 yrs ago..no individual photocells on...

 

[RF Lighting]

Did you see the contactor(s)? Did they pull in when you covered the cell? Perhaps there's a time switch somewhere you didn't see?

I've wired lights like this so they come on at dusk till midnight, then 6am till dawn.

It's more bizzare that one of them comes on though.

 

[thomo27]

yes the contactors are alongside the db..
didn't hear it kick in as was outside covering the cell..
we would normally stick a timeclock into this set up so the lights dont run all night..
the lamps are metal halides and the guts in the fitting contain the ignitor, capacitor etc..
on the new post I did I actually put a plug top onto the head and tested it before I took it up the scaffold...again I had 240 v but the lamp didnt come on..

maybe they are slow starters