One contactor for two elements?

[sflegacy]

So after a bunch of reading I am finally starting to assemble the control panel my electric brewery. The design is strongly influenced by Kal's panel except I am planning on running three elements HLT, MLT, and BK.

I guess I miscalculated when ordering parts and only ordered three contactors and three SSR's, which leaves me one short on contactors when you factor in that one contactor will be used to supply power to the panel.

I plan on using a 3 way switch to control the HLT and BK elements so that only one of the elements can run at a time. Is it possible to wire up both of those elements on the same dpdt contactor and have it work as it should? I just can't seem to wrap my head around how this might work. Both elements will still have dedicated SSR's. I can order another contactor but I'm running out of space in the enclosure pretty quickly!

Any help would be appreciated. I'll make sure and get a build thread going as I get a little farther along!

 

[Mb2658]

You are planning on putting an element directly into your mash tun? I think that you might have issues with even heat and scorching.

 

[jCOSbrew]

If you want to follow Kals wiring diagrams and panel layout exactly then just get the extra contactor. Is your panel design 50amps, can you run 2 elements at once?

Otherwise there are a couple options:
1. Wire the estop and on/off switch to disable the coil of all 3 contactors for all 3 elements. You could also run lower power 110v (PIDs, etc) and possibly 1 or 2 pumps (depending on current) through the 10amp contact blocks on the estop and on/off switch. You would probably need 3 contact blocks on the estop and on/off switch.

2. Use a main power contactor and share one contactor with the HLT and BK.
Use 2 sets of contacts on the 3-way switch. One set of contacts enables the contactor coil when the HLT or the BK is selected and disables in the middle, off position.
A second set of contacts routes the PID SSR output signal to the appropriate SSR for the BK or the HLT.

 

[sflegacy]

You are planning on putting an element directly into your mash tun? I think that you might have issues with even heat and scorching.

Sorry for not being clear. I actually will have the element in a rims tube.

 

[sflegacy]

If you want to follow Kals wiring diagrams and panel layout exactly then just get the extra contactor. Is your panel design 50amps, can you run 2 elements at once?

Otherwise there are a couple options:
1. Wire the estop and on/off switch to disable the coil of all 3 contactors for all 3 elements. You could also run lower power 110v (PIDs, etc) and possibly 1 or 2 pumps (depending on current) through the 10amp contact blocks on the estop and on/off switch. You would probably need 3 contact blocks on the estop and on/off switch.

2. Use a main power contactor and share one contactor with the HLT and BK.
Use 2 sets of contacts on the 3-way switch. One set of contacts enables the contactor coil when the HLT or the BK is selected and disables in the middle, off position.
A second set of contacts routes the PID SSR output signal to the appropriate SSR for the BK or the HLT.

Hey thanks for the reply! Most of that went straight over my head so I'll probably need to read it a couple hundred times before it sinks in. Maybe it will just be simpler to get the extra contactor.

I was planning on just running it off a 30 amp circuit that was wired for a dryer. I was hoping to just use smaller elements for now until I upgrade to a 50 amp circuit. I figure that I could run 240v 3500 watt elements in the HLT and Boil kettle (with 3 way switch) and a 240v 1500 watt element in the RIMS tube. I am only going to use one pump so I'm thinking the 30 amp circuit would be ok set up like this. I might even be able to step up the wattage on the boil kettle to a 4500 watter? Please correct me if I'm wrong in my thinking.

I see you're in the springs. I live over near the olympic training center. Thanks again for chiming in.

Edit: after reading through option number 2 it's starting to make sense. Is there a wiring diagram floating around for this?

 

[jCOSbrew]

OK, I still don't understand the requirment for 3 elements. Don't most people use 2 vessels with RIMs?
Cant you heat the stike water and sparge water in the BK and transfer MLT, maintain mash temp with RIMs?

 

[sflegacy]

OK, I still don't understand the requirment for 3 elements. Don't most people use 2 vessels with RIMs?
Cant you heat the stike water and sparge water in the BK and transfer MLT, maintain mash temp with RIMs?

Where do I transfer the wort while I'm sparging if the BK is full of water? I'd love to only have to use 2 elements but I just don't see how it's possible. I suppose I could just use a cooler for the HLT and just transfer the water from the BK into the cooler. I'm thinking the HLT element will be used to heat strike and sparge water, the RIMS element will maintain temps during recirculation and the BK element will be used for the boil. It's going to be a two tier setup with the HLT up high. I'm definitely open to suggestions though. Please let me know if I'm overlooking something.

 

[BadNewsBrewery]

You can batch sparge with only 2 vessels - heat your sparge water in the BK, dump it all into the MLT, then pump back to the BK. You need a MLT big enough to do it, and you have to decide that you want to batch sparge, but it's possible.

 

[sflegacy]

You can batch sparge with only 2 vessels - heat your sparge water in the BK, dump it all into the MLT, then pump back to the BK. You need a MLT big enough to do it, and you have to decide that you want to batch sparge, but it's possible.

Thanks for the suggestion. I currently batch sparge with a cooler and that works pretty good but I figured it would be nice to have the option to gravity fly sparge if I wanted to experiment with that. It's looking like I'll probably just add the fourth contactor and do it right. It's gonna be a little cramped but it should all fit in the enclosure.

 

[BadNewsBrewery]

Your other option is to get rid of the power switch, use the EPO to trip the GFCI breaker, and then use the act of plugging in your panel to turn it on. Maybe not a great option, but an option...

 

[skipper1953]

When you are finished mashing, just unplug the MLT or the HLT and plug in the BK in its place. You still have contactors controlling the elements and a dedicated main power contactor.