Using magnetic contractors with dc

[easttex]

I think you'll be fine as long as you don't switch directions under a load with the controller fired up. What I'm envisioning is a pair of contactors tied together by an interlock so you'd have an either/or situation for direction. If I recall the wiring diagrams correctly, that's the standard method for reversing a 3ph motor as well.

While I'm thinking about it, the DC disconnects I've seen guys like Eaton advertise for solar applications are usually just a 3 pole contactor rerated for the DC current it's rated to carry. The theory is to break the DC circuit in three places to prevent contactor wear or welding. And, it's cost efficient to do so because the manufacturers can simply repurpose a contactor from a 3 phase AC application and use that.

 

[Hukshawn]

I've basically done that with this setup. these two contactors are set up as polar phases essentially, once it's wired to the motor. Right now they're just activating dry. But it's one or the other. Can't be both. I have it electrically and physically set up so both cannot be triggered at the same time and just toggle back and forth with each button press. The stop button is wired to the controller. It engages the stop sequence in the controller so when I change directions or just restart in the same direction, everything, including the contactors start sequence at zero volts no matter what.

 

[Hukshawn]

I re-read that and I think it makes sense... I'm tiiiired, there might be some missing words here and there. Please excuse. Lol