multi 9 contactor problem

[bilsea]

got a prob with merlin gerin multi 9 contactors, had a fault on the lighting circuit which tripped out the contactors, cant for the life of me find where they are fed from! Is it just a case of resetting the circuit breaker which feeds the A1 and A2?

 

[Mr Mark Sparks]

check for voltage across a1 a2 to make sure coil hasnt failed if no supply what controls a1a2 ie clock , photocell etc

 

[bilsea]

check for voltage across a1 a2 to make sure coil hasnt failed if no supply what controls a1a2 ie clock , photocell etc

no voltage across a1,a2 just continuity, no diagrams at dis board from installer explaining anything just got banks of contactors that need reinstating and just wondered whether is is as simple as reinstating the tripped circuit breaker which feeds the contactors, saying that I have checked all the breakers in the board and they are all switched on!?

 

[Sintra]

As stated you need to find what is actually controlling the coil so as you can test complete circuit.

If you were just to reset mcb it might remain energised until whatever switching device switches. It could be on this part of the circuit that there is a fault that trips mcb.

 

[bilsea]

basically what im asking is how would I re-energize the coils within the contactor so that the contacts are pulled in magnetically to complete or open the circuit they are switching.

 

[Sintra]

basically what im asking is how would I re-energize the coils within the contactor so that the contacts are pulled in magnetically to complete or open the circuit they are switching.

no voltage across a1,a2 just continuity, no diagrams at dis board from installer explaining anything just got banks of contactors that need reinstating and just wondered whether is is as simple as reinstating the tripped circuit breaker which feeds the contactors, saying that I have checked all the breakers in the board and they are all switched on!?

If all breakers are on then it could be that the coil is not receiving a switched line from time clock, photocell etc etc. What you really need to do is find what is controlling the coil circuit.

Might be something like a hand / off / auto switch in wrong position or faulty timeclock etc.

 

[bilsea]

so am I right in saying that the supply from the mcb doesnt dirctely feed the contactors, and that the feed from the mcb goes to a photocell or timer first before being connected to the a1 and a2 terminals of the contactors?

 

[Guest123]

so am I right in saying that the supply from the mcb doesnt dirctely feed the contactors, and that the feed from the mcb goes to a photocell or timer first before being connected to the a1 and a2 terminals of the contactors?

I would say so yes...otherwise the coil would be energised all the time so whatever was being fed by the contactor would also be on all the time.

 

[davelerave]

the control circuit mcb/fuse feeds the contactor controls

timer/photocell combination is common for lighting conrol ie: photocell switches on lights and timer switches off