External Lights through timer and contactor via photocell

[kmulcahy1994]

Hello all,

I know this is very simple but I would like some advice please.

I am installing a new circuit to feed 5 external floodlights.

It is to be controlled by a digital timer with volt free contacts through a 2 pole contactor wired with the existing photocell which also does a couple circuits with external lights.

There will also be a 20A DP switch with a neon indicator to over ride the circuit for testing purposes during daylight.

The way I would wire it is my feed from C10 RCBO to top of contactor. Then the bottom of my contactor will go out to my floodlights.

Now this is the part I am getting confused with. I need to take a feed from the existing control circuit to feed my new timer/contactor. Am I right in saying Permanent Line to my time clock then link to the common of time clock and then N/O to my contactor coil A1. I will also take the existing photocell A1 from another contactor to my contactor. I will then take the L out from the 20A DP switch to A1 of my contactor. The only issue is that there is already an existing override switch for another external lighting circuit so when that is switched surely it will backfeed to my 20A DP switch.

I can’t think of how to prevent this. Any help will be greatly appreciated.

 

[cliffed]

Use the existing override switch for your new lights obviously using the same control circuit

 

[Flanders]

You only want one control circuit . Connect the time clock in series with the photo cell and use existing over ride switch.

 

[kmulcahy1994]

Use the existing override switch for your new lights obviously using the same control circuit

Job spec asks for a seperate over ride switch with neon indicator to operate the floodlights but they want it wired from the existing photocell? Is this possible even if there is another over ride switch for the other ext lights which is also on the photocell.

 

[davesparks]

Is the photocell intended to wokr in series or parallel with the timeswitch?

Instead of picking up the photocell S/L from the coil of another contactor you could fit a n/o aux contact to that contactor and use this to interface the photocell signal with your new controls.

 

[Gnasher]

Hi

Permanent live into one side on th N/0 contacts on time clock. Other side of N/O time clock contact to supply photocell. Switched live of photocell onto contractor.

Override switch between permanent live side N/O on time clock and contractor.



Hope this helps.

 

[davesparks]

Hi

Permanent live into one side on th N/0 contacts on time clock. Other side of N/O time clock contact to supply photocell. Switched live of photocell onto contractor.

Override switch between permanent live side N/O on time clock and contractor.



Hope this helps.

Not sensible, this will cycle power to the photocell with every switching cycle of the timeswitch. This will lead to tbe photocell entering a self test mode every time and also shorten it's lifespan with the constant power cycles.

It would be more sensible, if the photocell is required to be in series with the timeswitch, to have the volt-free output of the timeswitch after the photocell.

 

[mainline]

Job spec asks for a seperate over ride switch with neon indicator to operate the floodlights but they want it wired from the existing photocell? Is this possible even if there is another over ride switch for the other ext lights which is also on the photocell.

Is there a need for a timer and a photo cell.

Is there a need for a contactor ?