Contactor specification and usage

[ADWSystems]

This question probably has more power behind it than usual here, but this is the best place I could think of to ask.

I'm looking to locate a contactor for use in running a 2HP 220VAC motor. I'm not entirely sure of which specs to look at. I know about the coil voltage, the HP rating, the current and voltage ratings; are there any others I should watch for?

Being a 220VAC circuit, there is no neutral wire, just two hot lines. The contactors I have located (such as Telemecanique LC1D12BL) are either for 1 or 3 hot wires, not two. Is there a problem only using two of the three? Some contactors, such as this one, come with an auxilliary contact. Can I use the third contactor connection as a second auxilliary contact for another low voltage circuit?

 

[Gary B]

I don’t see why not. None of the contacts are electrically connected so what you do or don’t do with one does not really matter. As long as the contacts are rated to carry the current and can interrupt the voltage/current you should be OK.

 

[Reloadron]

You have a 220/240 volt single phase 2 HP motor and you want a motor starter. I don't know where you are located but if in the US then pick your poison from here. I would think you want a motor starter with overload protection? You don't mention enclosed or open frame? If enclosed you don't mention any NEMA specifications?

Also, the Telemecanique LC1D12BL you mentioned should work OK using 2 of 3 contacts as long as you externally use some protection for your motor (fuse) and the aux contacts can be used for whatever. You should note the following:

Horsepower Rating (3-Phase) 3HP@200/230Vac - 7.5HP@460Vac - 10HP@575Vac

You apparently have single phase 2 HP so make sure you don't exceed the ratings. You might be close.


Ron