Lighting contactor question

[Mannyv2]

If the contactor has clearing contacts you could use a standard 3 way / 4 way shitch set up with a relay

Can you tell how please

 

[hillbilly1]

That would make the extra cost of a mechanically contactor held a total waste.

Not necessarily, most EMS is set up that way, since coil voltage is not constant with mechanically held, no loud humming when debris gets on the mating surfaces, also the relay can be configured to “fail” the contactor closed if the relay coil fails or the EMS crashes. If the mech held coil fails, it stays in the last position, and can easily be manually overridden to get the lights back on if it failed in the off position. Electrically held, not so easy! LOL!

 

[sgtsparky]

I have used electrically held for years, an aux relay that maintains the control voltage once a pushbutton is actuated and a second pushbutton to break the control voltage (if gunk gets on the contactor it will buzz I work in a Mill and it is filthy and I rarely have any issues), I have this setup in both 24v and 120v at different buildings based on what my PLC output card voltage is so the lights can also be controlled by PLC , then on off stations at major entries.