Any ideas, on this one..

[nathz29]

Evening,

Visited a site today for an external lighting fault, bollards to be specific.

The circuit contains six bollards and a contactor brought in via a photocell.
Bollards sited around a mill conversion 4 to the front and 2 to the rear.

Protected by a 6A mem rcbo

They rcbo trips whenever the contactor de energises if all the bollards are in cct, if isolate the two to the rear the trip does not occur.
No signs of water ingress.on most bollards, ir testing on the accessible cabling to the rear appears ok, ir tested n-e ok,
The two bollards to the rear show signs of water ingress, had those in bits and checked the connections replaced corroded lamp holders and terminals (bollards are just contain lampholders via fused terminals, no gear in there thankfully)
As soon as any load is added to the rear bollards, it trips.
I can't access all of the cable run to the rear bollards as it's within the mill walls and looks like it goes through atleast one apartment.

Scratching my head on this one a little?

I'm thinking it has an earth leakage problem on this cct, and the wet cold weather has pushed it over the edge.

Any ideas?

Cheers
Nathan

 

[westward10]

Does it need the rcbo.

 

[Octopus]

Disconnect lights and IR the cables?

 

[Pete999]

Evening,

Visited a site today for an external lighting fault, bollards to be specific.

The circuit contains six bollards and a contactor brought in via a photocell.
Bollards sited around a mill conversion 4 to the front and 2 to the rear.

Protected by a 6A mem rcbo

They rcbo trips whenever the contactor de energises if all the bollards are in cct, if isolate the two to the rear the trip does not occur.
No signs of water ingress.on most bollards, ir testing on the accessible cabling to the rear appears ok, ir tested n-e ok,
The two bollards to the rear show signs of water ingress, had those in bits and checked the connections replaced corroded lamp holders and terminals (bollards are just contain lampholders via fused terminals, no gear in there thankfully)
As soon as any load is added to the rear bollards, it trips.
I can't access all of the cable run to the rear bollards as it's within the mill walls and looks like it goes through atleast one apartment.

Scratching my head on this one a little?

I'm thinking it has an earth leakage problem on this cct, and the wet cold weather has pushed it over the edge.

Any ideas?

Cheers
Nathan

Is the rcbo tripping on a fault or is it the cb part that's causing the trip, ie fault or overload?

 

[Strima]

What about L-E IR? And as above, RCBO needed?

 

[buzzlightyear]

why don't you disconnect the contactor to see if it is that.

 

[Pete999]

why don't you disconnect the contactor to see if it is that.

Lights won't work if he disses the contactor

 

[nathz29]

Fault not on overload, cct will energise and the trip only occurs when the contactor de energises, all points to an earth neutral fault in my head but can't isolate it

 

[buzzlightyear]

so what are the IR on testing ,

 

[nathz29]

I could take the contactor out, but it only trips when the rear bollards are in cct, the remaining 4 bollards are controlled and function via the same contactor.

 

[Pete999]

Fault not on overload, cct will energise and the trip only occurs when the contactor de energises, all points to an earth neutral fault in my head but can't isolate it

Poor Neutral connection somewhere, done any earth leakage clamp testing??

 

[nathz29]

L-E ir is ok too, all ir results around 30M ish.

Havnt done any earth leakage testing as I forgot my clamp!

 

[buzzlightyear]

by passing the contractor would be better and go from there .
do a IR first and leave the RCBO in and see where it takes you.

 

[static zap]

Don't rule out leakage in Photo cell ,
(that you may be reluctant to IR too heavily)
--Sounds marginal somewhere,
+ Spike from contactor !
..Hence like try without contactor comment...

 

[buzzlightyear]

do you know static. you might be wright on the photo cell.

 

[Octopus]

Are they all LED's - could it be start up current?

 

[nathz29]

All CFL lamps
I did consider the photocell but as an after thought after I'd left the site,
all good points thanks. I'll be revisiting next week couple of additional items to check on site and then I'll be back onto this one.

 

[buzzlightyear]

keep us informed on this one because I will be biting my nails .

 

[nathz29]

I know its enthralling isn't it....

 

[buzzlightyear]

they say two heads are better then one trying figger things out.