Garyr2973
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I want to run 4- 3000w elements (2 in HLT, 2 in BK). I know I'll need 4 SSRs but I want to run 1 PID per tank. Anything wrong with just wiring the SSRs (2 per) in parallel coming off the PID?
4 elements, 4 SSRs, 2 PIDs
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jeffmeh
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For each pair, say the 2 in the BK, do you ever plan to run one element without the other? I don't know why you would, because the PID can manage the ouput for you. In that case why not just use one 40amp SSR for each pair, and wire the pair of elements in parallel? Again, IANAE, so hopefully someone else can confirm.
BadNewsBrewery
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The PID should be able to adjust its logic fine, my only question would be amperage - how many amps does the PID put out, and how many amps does the SSR coil draw? As long as 2 SSRs don't need more juice to switch than the PID can provide you should be fine.
jeffmeh
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(2 x 3000w) / 240v = 25a. One 40a SSR should be able to drive 2 3000w elements with no problem. The PID is sending control signals over something like 12V DC and is only switching the SSR, so what the SSR is powering is not relevant to the amperage draw of the PID.
Edit: At 120V = 50a, so you would need a higher rated SSR.
Edit: At 120V = 50a, so you would need a higher rated SSR.
I have a BCS but I think this logic is the same. You just need to connect the pid OUT (turn **** on) to both of the ssr's that control those 2 elements. I just ran the OUT to one ssr then hopped the wire over to the next. Then when the PID OUT turns on it activates both ssrs. It doesn't know or care it's connected to more than one ssr, it just sends the low voltage signal to say go. It's just going to keep going on and off to maintain whatever you set it at based on the IN (temp probe).
Not sure on a PID but I had to do this with my multiple element rig because each OUT on the BCS is associated with an IN (temp probe). You can't have 1 IN controlling 2 OUTS so you make 1 OUT control 2 things after it leaves the controller.
Boy I don't know if that makes sense. Forgive me if I'm wrong, as I said I haven't worked with a PID. Maybe someone else can verify.
Not sure on a PID but I had to do this with my multiple element rig because each OUT on the BCS is associated with an IN (temp probe). You can't have 1 IN controlling 2 OUTS so you make 1 OUT control 2 things after it leaves the controller.
Boy I don't know if that makes sense. Forgive me if I'm wrong, as I said I haven't worked with a PID. Maybe someone else can verify.
jeffmeh
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I definitely may be missing something, so someone please correct me if that is the case. If you want to control two heating elements simultaneously, why would you not have your 1 out go to 1 sufficiently rated SSR, and have the two elements wired to the SSR in parallel? Having 2 SSRs that are always switching at the same time would work, but with one additional SSR to purchase and to be an additional point of failure.
Garyr2973
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Thanks for all the replies everyone. I actually didn't think about wiring the elements in parallel but that's a great idea. I will get a bigger SSR and heat sink to match. I'd love to just go with a single bigger element but due to only having 120v, I think a single element would take forever to get water/wort to a boil. I thought about going to a single 3000w element in the HLT then adding a RIMS to help it out but I guess that won't help heating spathe and mash water will it?
jeffmeh
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Actually, in looking at your other thread, it looks like you are planning to run two separate 120v circuits, one for each element. In that case you may need the two SSRs. You can certainly run two outputs in parallel from an SSR, but you actually have two inputs as well. Someone with more knowledge than I will have to chime in here.
Garyr2973
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Ill have a total of 3 circuits but one will be used for the pumps. I was thinking one would power the pumps (2), and one circuit for each of the two elements in the HLT. Then when it's time for the boil, I'd flip the switch to move the two circuits to the boil kettle? Does that make sense?
BadNewsBrewery
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My comment on combined draw was not regarding the elements but the PID output. The SSR coils draw some amount of power and I'm sure the PID output isn't huge. Sounds like 2 SSRs is doable though.
I still find it odd that you have three circuits run to one room in your house. Did you have extras installed?
I still find it odd that you have three circuits run to one room in your house. Did you have extras installed?
jeffmeh
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Yes, it makes sense to me. I would emulate the 3 position switch setup Kal uses to ensure that you never try to fire all four elements at once, but I would simplify as much as possible. For example, you could just use 2 inexpensive switches (household light switches, even) to control the 2 pumps. You have some very interesting planning ahead. 
Garyr2973
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Oh they aren't to one room. One goes out to the garage (where ill be brewing) the second is the outside circuit for the outlet on the back of the house and the third ill run out of the house with a cord.
BadNewsBrewery
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Gotcha, makes more sense now. Don't forget to look into power loss over distance for various size extension cords and get one bigger than you need to cut down resistance. Your idea shod work though.
Please let me weigh in a little bit. /\ You only have 120V power available. You are planning on using 3000W elements. If those elements are 120V rated elements each will draw 25A which is more than a 120V circuit can handle. If they are 240V rated elements they will only provide 750W when run on a 120V circuit. This will defeat your whole plan.
I suggest that you plan on using 1700W 120V elements bostonheatingsupply.com - SP10874KL as they will draw 14.2A each. With 2-120V circuits available this will make your system very doable. You will have enough power to have a decent boil.
BTW, if you need a diagram for such a set up, it's not all that hard to do.
Garyr2973
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PJ- thank you. Your input is appreciated as always. The 3000w were 120V so yes that would put me over the 20amps. I know you make some great diagrams. I would understand it if it was 1 element and could probably figure it out but if its not too much trouble I would definitely not turn down your assistance.
