Strange wiring???any sense from it?

[highspark]

Just been to call out. Car park lights not working. Fiddled round for 10 minutes got no power at any of the lights but 230v at timer in and out. Switched timer to permanent. Lights come on then 2 mins later off again.

Had a good look round and spotted a sensor on side of building. Covered sensor with wooly hat and hey presto lights workin on permant and timed.

Why oh why has someone installed a day/night sensor with a timer aswell? Any thoughts?

 

[Guest111]

Simple answer the timer powers the lights to come on at a set time,put a photocell in as well and you don,t have to adjust timer for summer and winter, also combining both allows you to turn lights off while still dark,eg on a car sales pitch after midnight when no passers by to see cars.

 

[Guitarist]

Can't think of any reason why you would want both...

 

[highspark]

I still find there to be no reason why a day/night sensor needs to be installed the timer does all you say above by a flick of a switch!

 

[Guitarist]

I did think along the same lines as phil, but doesn't really make sense. Photocell with a switch would have been just as good.

 

[Geordie Spark]

Street lights have both (I think)

 

[Guest111]

Sorry maybe that was a bad analogy.lets say your staff come out of work at 6pm in winter its dark so you want your lights on,ok you fit a timer however the lights are on from say 6pm to 8 am cause its dark in winter but in summer it stay light till 10 pm and gets light at 5 am so you have to alter timer.but if you then fit photocell although power goes to cell from 6 pm to 8 am photocell only puts lights on when actually dark,also takes account of bad weather when it goes dark earlier in summer.

 

[sedgy34]

Simple answer the timer powers the lights to come on at a set time,put a photocell in as well and you don,t have to adjust timer for summer and winter, also combining both allows you to turn lights off while still dark,eg on a car sales pitch after midnight when no passers by to see cars.

well put!!! its more convenient

 

[Guest111]

Street lights have both (I think)

no modern street lights only use photocell,many years ago the main cable down the street had what was called a pilot cable in and this switched a group of street lamps,on motorways 1 photocell controls a bank of lights which is why they come on in sections,some sections now have a timer also to turn lights off between midnight and 5 am

 

[sedgy34]

Can't think of any reason why you would want both...

in my past experience its down to what the customer requires

 

[highspark]

It's more convenient? Well why have timer in the first place? It doesn't make sense.

 

[Guest111]

well put!!! its more convenient

Yes Sedgy I try but sometimes I have difficulty putting down in words what i want to say,and sometimes it can sound a bit patronising.

 

[Engineer54]

Sorry maybe that was a bad analogy.lets say your staff come out of work at 6pm in winter its dark so you want your lights on,ok you fit a timer however the lights are on from say 6pm to 8 am cause its dark in winter but in summer it stay light till 10 pm and gets light at 5 am so you have to alter timer.but if you then fit photocell although power goes to cell from 6 pm to 8 am photocell only puts lights on when actually dark,also takes account of bad weather when it goes dark earlier in summer.

And it's also standard practice, for the very reasons as outlined by phil d!!

 

[pjcomp]

Well why have timer in the first place? It doesn't make sense.

Photocell switches the lights on when it gets dark (variable time), timer switches them off (fixed time), otherwise they'd be on all night. Makes perfect sense to me.

PJ

 

[Guest111]

It's more convenient? Well why have timer in the first place? It doesn't make sense.

ok Highspark think this way you want lights on outside your house until everyone is home at say 11pm,first person gets in at 5pm ok now if you put a photocell on then lights are on all night right? put a timer on and you have to adjust it for summer and winter.put both in and if its dark at 5pm the lights come on if timer is set to go off at 11 30 then although its still dark timer cuts power and lights go off.no having to alter anything for summer or winter,