1 SSR 2 elements

[mcmidc]

I'm looking to automate my boil kettle with pid/ssr combo. Right now I have 2 1440 watt elements in there that I control off of switches(5 gallon batches). My understanding is that a 1440 watt element is going to pull about 12 amps each. So can I use one 40 amp ssr to fire off both elements or am I going to need one ssr for each element? It's not a like it'll cost a bunch more for another ssr and heatsink but it'd be nice to just have to wire one in to the pid.

 

[bohdan987]

i would do 2-20amp relays, just in case that one of them craps out on you in a middle of the boil. having a plan B is always nice.

 

[samuelpeter]

Are you running these off of 240v or two separate 120v circuits?

 

[The Pol]

1440W would be a 120VAC element, so that would be 120VAC and a neutral, so he will need a single 30A circuit

 

[CodeRage]

Pol's right, thats pretty big for a 110V circuit. Get above 20 amps and it's usually 240v. Do you have a circuit that big?

With all that said. Yes you can run it off of one SSR. You can also run 2 SSRs of the same PID without any fuss. Just wire them in parallel

 

[mcmidc]

Pol's right, thats pretty big for a 110V circuit. Get above 20 amps and it's usually 240v. Do you have a circuit that big?

With all that said. Yes you can run it off of one SSR. You can also run 2 SSRs of the same PID without any fuss. Just wire them in parallel

I'm running them off of 2 seperate 20 amp 120v circuits. Thanks I kind of thought it wouldn't be a problem to run them both off the same ssr but wasn't sure. Is there any reason to use 2 separate ssrs vs just one? Seems running just one 40 amp cuts back on cost and space needed for installation in the box. Thanks for the replys guys.

 

[jjyoung]

Unless the SSR that you're using can control 2 independent outputs then you'll need 2 of them since you're planning on driving them from 2 separate 110V circuits. .

 

[BrewBeemer]

Just us a SSRD.

 

[jjyoung]

Just us a SSRD.

I don't think I'd advise that with 2 separate 110V services. SSR = Solid State, so there isn't a mechanical isolation. If the SSRD fails in a spectacular way you might have the services short, which would make it REALLY spectacular.

 

[BrewBeemer]

I don't think I'd advise that with 2 separate 110V services. SSR = Solid State, so there isn't a mechanical isolation. If the SSRD fails in a spectacular way you might have the services short, which would make it REALLY spectacular.

An SSRD failure still will be two separate switched legs no way to short out to each other, L1 to L2, failing to a NC vs NO position yes that can happen. Then again a manual switch or relay is upstream of the SSR's or SSRD's as a common sense safety item. I should retract these words of common sense as it isn't that common.