coil burden

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nizak

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Would anybody know off hand what the coil burden would be for a 30 amp 2 pole lighting contactor? 120volt coil. I have a situation where I've got 18 contactor's located in a enclosure all controlling exterior lighting on a large property.
All lights can turn on and off at the same time.Currently there are several 7 day time clocks that only provide coil activation to the contactor's and the owner does not want the hassle of constantly resetting these mechanical behemouths. Past owner had a wide variety of on/off settings that are now not needed. If applicable I would propose using 1 inexpensive Intermatic spst clock to handle all.
 
nizak said:
Would anybody know off hand what the coil burden would be for a 30 amp 2 pole lighting contactor? 120volt coil. I have a situation where I've got 18 contactor's located in a enclosure all controlling exterior lighting on a large property.
All lights can turn on and off at the same time.Currently there are several 7 day time clocks that only provide coil activation to the contactor's and the owner does not want the hassle of constantly resetting these mechanical behemouths. Past owner had a wide variety of on/off settings that are now not needed. If applicable I would propose using 1 inexpensive Intermatic spst clock to handle all.
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Did you consult with the contactor manufacturer? I know that the manufacturers that I had worked for included this information as part of the catalog specifications.
 
I agree with templdl. Coil load varies with make and model.

But I will guess the burden is less than one amp per contactor... :D
 
Should be fine. If your coils draw too much you could always use the the digital timer to trigger a control contactor or a 120v relay.
 
J.P. said:
Should be fine. If your coils draw too much you could always use the the digital timer to trigger a control contactor or a 120v relay.
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Even if they don't draw too much steady-state current, the inrush required may be too much for the circuit impedance.
Besoeker said:
But better not to have all 18 of them pull in at the same time.
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In this case may have to install two timers with slight timing disparity, or use a time-delay ON relay to trigger a portion of them.
 
Besoeker said:
But better not to have all 18 of them pull in at the same time.
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McMaster-Carr as well as many other sources offer two terminal timers you can put in series with the coil, offering time delays from a fraction of a second up to several minutes. With a few of these you can have one master timer operate all lights but have them come on in sequence.
 
Barbqranch said:
McMaster-Carr as well as many other sources offer two terminal timers you can put in series with the coil, offering time delays from a fraction of a second up to several minutes. With a few of these you can have one master timer operate all lights but have them come on in sequence.
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Got a link?
 
Apart from concerns about the inrush current of the 18 contactor coils possibly being too much for a cheap timer, what about the effect on the feeder or service ?

18 contactors suggests a substantial load with possible risk of the feeder or main tipping if it all comes on at once.
I would therefore suggest the use of delay modules as suggested above. The exact delay is not that important provided that "all on at the same instant" is avoided.
 
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