industrial contactor question

[TimK]

I have machine that uses contractors with 240V AC coils. Is there a simple way to temperarly use a contractor with a 120V AC coil.

 

[ronsimpson]

Buy a 120V version.
Use a 110 to 220 transformer to get 220 from 110.

 

[shortbus=]

If the contactors are same brand and model just switch the coils.

 

[Reloadron]

Per shortbus, most large industrial contactors, depending on make and model, offer a coil kit. Should this be the case you simply remove and replace the coil with a different voltage coil. Again, this depends on the make and model of the contactor. When that is not possible and replacing an entire expensive contactor assembly is not possible a trick I have used would be to get a 240 / 120 volt control transformer and use it backwards applying 120 VAC to the secondary and use the primary 240 VAC side to drive the contactor coil. That works well as long as the VA rating of the transformer can deliver the needed coil current.

Ron

 

[shortbus=]

What I was trying to get at was to take the coil from the 240V contactor and put it on the 120V replacement contactor.

 

[Reloadron]

Sorry, my bad as I misunderstood.

Ron

 

[Diver300]

You could use just about any transformer that has a VA rating equal or larger than the coil rating, and has a primary wound for 240 / 120 V. You can leave the secondary open and use the primary as an autotransformer.