Brewer's Hardware RIMS Build

[EvilBrewer]

There is no problem using a contactor that is rated for more amps, just do not want to use one rated for less. I went with the 20amp ones because they were cheaper at the time...

Can anyone explain the difference between a definite purpose contactor and a general purpose power relay (for example a DPDT power relay)? I understand the principle of using them...but why use one over the other? Reason I ask is because I've seen both types used in RIMS and/or all electric setups. Trying to determine which one is more appropriate for my build.

 

[crazyirishman34]

From what I gather the contactor turns off both hot legs while the relay just turns one off

 

[EvilBrewer]

Can anyone explain the difference between a definite purpose contactor and a general purpose power relay (for example a DPDT power relay)? I understand the principle of using them...but why use one over the other? Reason I ask is because I've seen both types used in RIMS and/or all electric setups. Trying to determine which one is more appropriate for my build.

I did some reading and the general answer seems to be that contactors and power relays perform the same basic function, however contactors are generally used to switch higher current lines. Put another way, a contactor is simply a power relay that is used for higher currents.

And I think there is an overlap between them--that is, high current power relays and (relatively) low current contactors that could be used somewhat interchangeably for a line with a current that falls within their rating.

So, I still don't know why to use one over the other but a contactor seems to be a safe choice.

Any insight would still be appreciated though...

 

[EvilBrewer]

Found a good explanation for anyone who comes upon this thread and has this same question:

https://www.homebrewtalk.com/f170/how-build-control-panel-part-1-a-199643/index30.html#post2615975

 

[EvilBrewer]

Thanks again for the assistance...here's the final product:

My new RIMS control panel