Lighting contactors

[sparkync]

Could someone explain to me the sequence of operation of a 100 amp, 3 phase, mechanically held lighting contactor, with a 120 volt coil? I have a job where the parking lights were not coming on. The coil is not pulling in. I traced the 120 volts from the photo cell to the top left side of the contactor on a N/O set of contacts. The other side of the N/O contacts is a jumper going down to the (I'm assuming??) unlatching coil. There are other wires going down to the other side of the contactor, which at this point I can't remember exactly. I think the wires were going to a set of contacts on the top right of the contactor. They are fed from another contactor that is labeled, "unlatch relay" (I think). That's where I'm lost. The visible coil is down at the bottom of the contactor, which I assume is the latching coil. I'm sort of foggy on this, so if someone could explain the sequence, I might be able to put it all together. Thanks for the help. The contactor is a "Westinghouse.
Cat.# A202K3CAMP2, Model C", if that helps any.

 

[hillbilly1]

The photo cell should not go directly to the latch input, it should power a single pole double throw relay, which in turn powers either the latch, or the unlatch inputs, but not both at the same time. the contacts you are seeing on the contactor are clearing contacts. they remove power to the coil once it is in the correct position (either open or close) I could not pull up that model, but most work the same way.

 

[sparkync]

Lighting contactor

Lighting contactor

Thanks for the reply. It's starting to come together a little at a time for me. I wish I could find a picture of the contactor so I could really get it's operation in my head, but unfortunately, like you said I could not find the Westinghouse number on the web anywhere. I understand that Cutler Hammer bought them out, so I'm sure there's another one similar out there somewhere. So far I haven't got a picture of one.. Thanks again for the help. Steve...