220v Pump/SSR Wiring Help Please!

Thread Starter

boilermanc

Joined Jun 3, 2016
10
Hi all, I am working through a pretty fun project and need some help understanding my wiring for a 220v 10amp pump using an SSR. I am wiring an arduino to the ssr as the "switch". the ssr then needs to control the 220v pump. 120v with one hot is pretty simple for me to understand. its adding the two HOT wires that mixes me up. I have found the attached picture that is what I want to do. Just replace the heating element with a pump. and the PID with an arduino without the power running into it. So I understand having the red 115v hot going to the relay and over to the pump. But if i run the other 115v hot to the pump will not turn the pump on? Seems like both wires should be powered until the relay is tripped. And yes I would have a fuse running on the red wire before the relay.

thanks in advance!


 

crutschow

Joined Mar 14, 2008
34,286
The motor will not run even if one of the 220V lines is still hot going to the motor, since there's no complete circuit, but for safety, and likely to comply with local wiring codes, you should use two SSR's, one for each leg of the 220V (or a DPST SSR if you can find one).
 

MaxHeadRoom

Joined Jul 18, 2013
28,621
For a start do not think of 120v as one hot, in reality it is two hots, just that one is grounded, but they are essentially identical.
I can see no reason why it does not work? Essentially you show fig 7.2 of the 220v hook up.
If you want to use two SSR you can parallel the inputs.
Max.
 

Thread Starter

boilermanc

Joined Jun 3, 2016
10
Thanks to both of you for the response. I think that helps me.

so to recap, if i run the black hot to one connection on the motor and then run the red hot through the relay and then to the motor i should be good. i would still put the fuse before the relay wire or should it go on the black hot?

thanks!
 
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