Relays and DIN breakers for 50A panel

[summerofgeorge]

I've been slowly piecing my control panel together in my head. Now I'm stuck on the relays that are needed. I'm going with a 50A panel and 2 5500W (possibly 1 4500W and 1 5500W instead) elements capable of firing at the same time. From what I understand, I'll need a 50A/240V DPDT (or DPST??) relay with 120V AC coil for the main power switch. Then separate 30A/240V relays for each of the elements? If I'm using 40A SSRs, do the relays need to be 40A too?

I'm also planning on putting in DIN mounted breakers. Probably 15A for the pumps/lights and 30A (or is 25A enough??) for the elements. With 30A(25A) breakers for the elements, can/should the relays and SSRs be 30A(25A) too? I'm basing most of my ideas off these diagrams from Tiber Brew's build: http://www.pjmuth.org/beerstuff/images/Auberin-wiring1-a11a-SWA-2451-5500w.jpg (not the final version) and http://www.pjmuth.org/beerstuff/images/Auberin-wiring1-a11-SYL-2362-4500w.jpg (I think the final version).

I guess to simplify my question, how many and what size relays and DIN breakers will I need? Thanks!

 

[BSD_Glass]

I just finished up my control box. I haven't made beer with it yet, but everything tests fine.

I have a 50 amp auber contactor for the main power in the box which feeds terminal strips. From the terminal strips, I split into (1) 15 amp single pole din CB and (2) 25 amp double pole CB's. Since I already had the DIN rail and some DIN stuff in the box, I wish I'd gone with DIN terminal blocks, but what I have is pretty clean looking and will work fine. I didn't know anything about DIN terminal blocks so went with what I know.

I have a 30 amp contactor on each heater circuit after the CB and that feeds into the 40 amp SSR then to the outlet. You want to oversize your SSR's as heat is what kills them so a 40 or even 50 amp SSR for a >25 amp heater is probably good. Externally mount your heat sinks or provide fan cooling to your enclosure.

Good luck! It took me about 2 days to wire everything up. It was a super fun puzzle and I'm happy to say I kept all the magic smoke inside my components.

Thanks to everyone here for making this build a lot easier for me to figure out.

BSD

 

[zeus53219]

I have some of these left. https://www.homebrewtalk.com/f16/contactors-e-brew-heating-elements-273489/

 

[summerofgeorge]

Thanks BSD! I saw your build post...looks like it's time to update with some pics of the finished product! I'm definitely interested in seeing it since it seems like our ideas are very similar.


zeus - thanks for the offer. I saw your post in another thread saying your contactors are better than the cheaper ones at auber. Why is this the case? I don't know anything about them so I'm just curious.

 

[BSD_Glass]

https://www.homebrewtalk.com/f170/my-2-pid-2-ssr-control-panel-build-318514/

That should be the link to my other thread detailing my control panel build.

BSD

 

[summerofgeorge]

Would it be okay to use 40A contactors for the elements instead of 25A or 30A? I was going to order some from amazon and it would be cheaper after shipping to just get 3 the of the 40A contactors

 

[BSD_Glass]

Yes.

You can always use a larger than required relay.

BSD

 

[summerofgeorge]

Thanks man. I thought that was the case but wanted to double check....slowly getting the final components.