Switching 220V contactors

[Deece]

I mistakenly purchased some contactors with 220v coils do I need to switch both legs to control it?

 

[BlkWater_brewer]

I would say yes, to avoid a constantly hot connection. However in my opinion you'd be better off getting the right parts and return these. If you have to switch both legs what is it you are gaining by using a contactor? May as well stay with the switch and leave out the contactor altogether. I could be wrong but all of the wiring diagrams I've seen suggest I may not be.

 

[doug293cz]

I mistakenly purchased some contactors with 220v coils do I need to switch both legs to control it?

No, you don't need to switch both legs. To close the contacts in the contactor, you need to have current thru the coil. Current only flows when you have an unbroken loop. Break the loop anywhere, and current flow stops. So, you can switch either hot line to control a contactor with a 220V coil. The advantage of contactors is they allow you to switch large currents with small currents, and in some cases low voltage. If you use contactors with low voltage coils, then you can attain added safety in your system, which may or may not be important depending on design and usage environment. When you get up to the point of switching 30A or so, the cost of switches can be greater than the cost of contactors. So, at some point contactors can save you money.

Brew on

 

[Deece]

That's kinda what I was thinking as well. Only reason I was going to use them is because I was planning on running a serial cable between my panel door and the backplate and was unsure it could carry the amperage for the pumps hence the contactors.

 

[The10mmKid]

I mistakenly purchased some contactors with 220v coils do I need to switch both legs to control it?

If you have 220V handy in the panel, use it.