Single-phase contactor with overload?

[MEP001]

Is there such a thing as a single-phase contactor with a thermal overload like these?

Most older washes I've seen just use a large 2-pole HVAC type relay, and I haven't found anything for an upgrade better than to use a 3-phase contactor. I haven't seen a problem from that, but I'm not sure if it even gives the right protection.

 

[Earl Weiss]

See

https://www.kleen-ritecorp.com/p-4119-allenbradley-motor-starter-24v.aspx

 

[MEP001]

I know that will "work," but I'm looking for a single-phase version. I remembered after I posted that a 3-phase will work since the thermal overload will trip if it drops a leg, but if there is a single-phase version I'd prefer to use that.

 

[RAATCB]

Can you jump T2 with a wire to T3 on the thermal overload side only? So basically if the second leg overloads it will be apart of T3 or "third leg" ?

 

[whitescout]

Most manufacturers use this version for single phase.

 

[MEP001]

Can you jump T2 with a wire to T3 on the thermal overload side only? So basically if the second leg overloads it will be apart of T3 or "third leg" ?

I've seen that done, not on the thermal overload but back into the top of the contactor. Seems like a jury-rig and may just introduce a failure point for no reason.

 

[MEP001]

Most manufacturers use this version for single phase.

Most manufacturers just build equipment for 3-phase and require it to be powered that way, then when it's to be installed at a single-phase location they just swap the motor and crank up the thermal overload.

 

[kentadel]

TrSys D contactors from Schneider are available with single phase sensitivity.

 

[MEP001]

TrSys D contactors from Schneider are available with single phase sensitivity.

Thanks, those look the same as the Telemechanique I've always used and even have the same part number, but I'll give them a call Monday and see what they say about using them on single-phase.

 

[wash4me]

http://library.automationdirect.com/how-to-wire-a-motor-starter-issue-5-2005/

Scroll down a bit and there's a section on how to hook a single phase to a 3 phase starter. This is the same way that all manufacturers recommend I believe. Basically it runs the load through 2 legs on L1 and T1. This allows the thermals to react the way they were designed and trip on overload.

You could also use just one metallic overload. Anything you do but use a 3 phase starter is going to be harder to get parts for. I have seen a Weg unit like you want and I can get you one if you want it but there's no benefit I am aware of.

 

[wash4me]

I know that will "work," but I'm looking for a single-phase version. I remembered after I posted that a 3-phase will work since the thermal overload will trip if it drops a leg, but if there is a single-phase version I'd prefer to use that.

Most of them just count on the higher amps that come from "single phasing" a motor to trip. Single phasing means losing one of the 3 legs of incoming power.