photocell problems !!!

[electrotec]

I recently installed some LED decking lights and some GU10 waterproof garden spots and instead of my usual choice of photocell Royce thompson ( or Zodion) i used an eterna minature photocell as it was less obtrusive and could be hidden. It has worked perfectly so when the customer asked if i could install photocells to control 3 x GU10 lamps fitted in the soffit above their garage door and 2 x GU10 lamps fitted in their front door porch i used the same type of eterna photocell as i had in the garden in both locations. Again they worked perfectly. The next door neighbour liked them so much i ended fitting the same for them.
I then got a call from my original customer complaining the lights werent coming on above the garage. After a quick inspection i found one of the GU10 lamps had blown but in the process caused the photocell to stop working. i changed the photocell and since then every time the lamps have blown either in the porch or garage in both my customers and their neighbours the photocell has stopped working and has to be replaced. The Gu10 lamps fitted in the garden have blown but they are not damaging that photocell. The only difference is the garden lights also have LED decking lights connected to the circuit. I have contacted Eterna and they have no idea. Has anyone had similar problems or got an ideas.
Many thanks Tony (Electrotec)

 

[Spudmiester]

Sounds to me like the GU10 blowing has taken the phocell with it because its not big enough to handle the extra current caused by the bulb going pop.

What are they rated at ?

Try switching through a relay.


Spud

 

[Moog]

Breaking capacity of the photocell? Total Load? MCB fitted as per instructions?

 

[old dog]

the only thing i can think of the circuit with the leds the diode is protecting
the photocell from surge

 

[Moog]

the only thing i can think of the circuit with the leds the diode is protecting
the photocell from surge

All lamps should have been in parallel so I dont think LED should not effect, I think the relay post or replace photocell for your usual choice is the way to go as clearly the photo cell is being damaged proberbly by surge when lamp blows.

 

[answers]

I know this reply is far too late for people above but I hear this problem all the time, The answer is very simple. The photocell needs a protection fuse because when lamps fail the fail to one of two states, either short or open circuit. If they fail to open circuit the photocell will continue to work after the lamp has failed. If they fail to short circuit the photocell has to carry the current until the fuse or breaker trips. If the wrong fuse is used then the photocell will weld the contacts and that will be the end for it. Choose the correct fuse and you should be ok. Choose a photocell with an oversized relay or triac and you reduce the chances even further. I always use Acetek photocells as these have neverfailed me. i hope this will help other who read this.