External lighting - am I missing something?

[polo1]

Situation - local rugby club. Clubhouse has 18 external bulkhead (Phillips) fittings each using 1 G23, 11w lamp; split into two circuits each on 6amp B type mcbs. Both circuits operate via a contactor & photocell.


Problem - one circuit mcb keeps tripping, holds for three/four evenings typically, then trips.


I've swapped the tripping mcb, checked insu res etc; checked each fitting, no obvious probs.


Any suggestions?

 

[Marvo]

Is there any kind of pattern that could be weather related or length of run time related? If the worst comes to the worst and you can't pick any issues up visually or by testing you could split the circuit and see if you can localize the problem that way.

 

[polo1]

Have you checked the photocell for ingress?

Another good point - no I haven't, but I will!

 

[polo1]

Is there any kind of pattern that could be weather related or length of run time related? If the worst comes to the worst and you can't pick any issues up visually or by testing you could split the circuit and see if you can localize the problem that way.

I'm thinking this is what I'll have to do. The weather has been wild of late, but the problem precedes the very stormy/wet weather. Any thoughts on a faulty ballast as a source of overload or am I clutching at straws?

 

[telectrix]

squirrels?

 

[polo1]

Very tasty fried! All of the wiring is internal and tubed or in metal containment.

 

[Marvo]

A trick I've used before is to install a minature fuse holder at each fitting and fit a fairly close rated fuse. They're pretty cheap and you can use a panel mounted type and solder tails to it and insulate with some heat shrink over the top of everything. If it's a rogue fitting that's causing the tripping then the next time it happens it will be the only fitting that doesn't light due to the blown fuse.

 

[Plonker 3]

Marco makes a good point.

Or if you don't have time to do that, Could you not disconnect the circuit half way and see what happens the after a few nights?

 

[Marvo]

It's really quick to install in most fittings if you pre-solder the tails before you go to site and go armed with a handful of Wagos or small sized chocbloc connectors.

 

[guest119]

Fit a transient voltage arrestor in each fitting, pennies each.
Could be killing the mcb when it switches off with voltage spikes, cheap fittings?
Seen it before and it made some mess of timeclock after timeclock till we nailed it. Timeclocks dont like 10kv.
At least the fittings are not from C.E.F.?


Boydy

 

[Plonker 3]

It's really quick to install in most fittings if you pre-solder the tails before you go to site and go armed with a handful of Wagos or small sized chocbloc connectors.

Never thought of that lol

 

[polo1]

Fit a transient voltage arrestor in each fitting, pennies each.
Could be killing the mcb when it switches off with voltage spikes, cheap fittings?
Seen it before and it made some mess of timeclock after timeclock till we nailed it. Timeclocks dont like 10kv.
At least the fittings are not from C.E.F.?


Boydy

Cheers for that ( and Marvo & Dillb too!), I was running out of ideas. Good few things to try.
The fittings are Phillips and are original to the build. The other half of the lights/building have been fine.
I normally quite enjoy fault finding, but this one is starting to grate.

Thanks again all for helpful contributions, much appreciated.

 

[Marvo]

No probs, let us know how you get on.

 

[Deleted member 72666]

Is the photo cell and contactor fed from the mcb that's tripping?

 

[polo1]

Is the photo cell and contactor fed from the mcb that's tripping?

The contactor (2 pole) is fed from the two 6amp mcbs, in turn feeding each of the lighting circuits. Have to check where the photo cell takes its feed from.

 

[Dizzy_Maskell]

Not a lose or snagged cable I've found this before all ok and IR clear but on occasion it would trip.
Turns out it was the slightest nick on the incoming cable someone had caught the insulation and every now and then it would touch the metal case of the fitting.
Although you said conduit and the ones I encountered where flex and so guessing bit more freedom to move

Just a suggestion