220v switch question

[truckmann]

I just got a Hot Rod heat stick and I'm going to build a controller to run it. Here is my plan for wiring it so far using a BrewBit controller to run one SSR for use in the HLT and using an SSVR to control when boiling. I'm wondering here about the switching of the leg to feed one or the other SSR. I ordered a 120v 3 position switch and then I realized it's only rated for 10 amps. Does anyone have a better idea how to handle switching this?

View attachment 1416533998710.jpg

 

[Brumateur]

First of all - since BrewBit has 120V output you will need an AC-AC type SSR. Like this one http://www.ebay.com/itm/Solid-State-Relay-SSR-AC-AC-25A-70-280VAC-240-480VAC-25A-/171052325183

You can use any amp rated switch if you will switch SSRs control circuit instead of output lines. See diagram below. Since the current through switch is very small <0.01 Amp any 240V rated DPDT switch will work.

 

[truckmann]

Thanks I do have the proper AC-AC ssr for the BrewBit. I think I get it. Instead of switching the hot leg to the input side of the SSR's I need to use a DPDT switch for the control legs of the SSR's.

 

[truckmann]

Here is my new plan. I wasn't sure of the state of the SSVR when the Rheostat is unhooked, but if it is in an open state with the rheostat circuit broken I think this will work great. Thanks again for the input Brumateur

 

[Bobby_M]

I haven't gone over the diagram, but one thing you can do is run the hot leg of the element line through the VSSR and then into the other SSR in series. While the resulting functionality isn't hugely advantageous, it does save you from having to switch anything. When heating the HLT, set your VSSR knob to 11 and set the PID to set temp. When boiling, set your PID temp setpoint to 220F and then use the knob.

 

[truckmann]

I haven't gone over the diagram, but one thing you can do is run the hot leg of the element line through the VSSR and then into the other SSR in series. While the resulting functionality isn't hugely advantageous, it does save you from having to switch anything. When heating the HLT, set your VSSR knob to 11 and set the PID to set temp. When boiling, set your PID temp setpoint to 220F and then use the knob.

I thought of doing that also. If I can make the switch work, I'd rather just not have the BrewBit controller involved at all when boiling. As long as the SSVR is open when the Rheostat is unhooked, the switch should work. Otherwise I'll have to switch the hot leg with a relay which adds some complexity and cost.

 

[truckmann]

I also kind of wonder if I really need the switch in the first diagram. As long as the BrewBit isn't sending an on signal, then the only power going to the element would be from the SSVR and if the BrewBit is sending signal then I think the power from the SSR would override the power from the SSVR. I'd just have to make sure the BrewBit was off or unplugged when boiling so only the SSVR would be active.

At least it seems it would work that way since power in to both SSR's comes from the same source. I'm not really sure if there would be any issues with both SSR's hooked up hot that way without a switch or not.

 

[Brumateur]

Sure you can use SSRs with no switch. However I beleive it's more convinient to have switch. This way you don' need to unplug BrewBit every time you want an infinite control.

 

[truckmann]

Sure you can use SSRs with no switch. However I beleive it's more convinient to have switch. This way you don' need to unplug BrewBit every time you want an infinite control.

I agree. I still plan on adding the switch. Actually have one I like ordered and on the way.

 

[truckmann]

All built and functioning.

 

[BrokenHorn]

Congrats! That's a fancy beer brewing chair there

 

[truckmann]

Congrats! That's a fancy beer brewing chair there

Ha ha! Yeah I think my wife picked that up cheap or possibly even free from an auction years ago. I have to keep her away from auctions or she will come home with a bunch of cheap crap that we don't need.