Introduction: Electric Brewery Control Panel on the Cheap

Picture of Electric Brewery Control Panel on the Cheap

If you are into home brewing then you have likely heard of "The Electric Brewery" created and run by a fellow named Kal. If you haven't then get over there and read up. This is the best homebrew setup out there, well thought out, well designed and effectively open source. It uses electric hot water heater elements, a three-kettle two-pump setup, and a process control panel to bring your home brewing to a new level of awesome and easy. Kal has designed a top-notch, no-compromises system that is safe, enjoyable and easy to use. However, it is expensive. Also, Kal is an engineer by training, and as a fellow engineer I cannot possibly leave well enough alone and must change his design. This is job security which is bred into all engineering types. You can substitute fittings and pots and pumps to reduce system cost, but the heart of the "Electric Brewery" system and one of the costliest is the control panel. Here I will show you how I redesigned Kal's control panel with cost in mind, bringing the cost down from around $1500 to $250 without compromising safety and with only a few compromises in function. I can attest to the fact that this control panel works and makes great beer. If that sounds good to you, then read on!

Step 1: Bill of Materials

Picture of Bill of Materials

The key to designing this kind of control system on the cheap is flexibility and availability. If you stick to the recipe strictly you may find that you cannot source the specified part locally or economically. Also, depending on your system you may be able to substitute a lower cost lesser performing part safely. So here I am going to present the parts that I used and you can use them as a guide for sourcing your own. In some cases the parts are from the internet and anyone can get them while others are local surplus and you might need to sub. I'll go into detail on what you should look for when choosing parts as needed. So without further ado:

3x DPST-NO 30A 120VAC relay (PN# G2290127 at
3x REX-C700 PIDs (
2x 60A SSR (
2x 60A SSR heatsink (
2x 30A 250VAC locking 3-wire receptacle (
1x 15A 120VAC two outlet receptacle (
1x 30A 240VAC 6 foot 4-wire dryer cord (
1x Keyswitch (local suplus but this one should work:
3x XLR 3-pin male socket (local suplus but this one should work:
1x 3/4" cable clamp = $1 (home depot)
2x On-off toggle switches (local suplus but this one should work:
1x On-off-on toggle switch (local suplus but this one should work:
2x 240V lamps (local suplus but this one should work:
Misc spade and ring lugs
Terminal strips for wiring buses (local surplus but similar to:

1/8" Birch plywood (approx. 6 square feet)
Scrap 1/2" plywood or solid strips for frame and back and sides
Titebond III wood glue
Screws for mounting components and securing sides to enclosure

Step 2: Design Changes

Picture of Design Changes

A number of features are eliminated from the control panel presented here as compared to the one designed on the Electric Brewery. The purpose being to simplify the design and reduce cost. The cheap design eliminates the safe start interlock, the alarm buzzer, the alarm light, the alarm reset button, the power on light, the voltage panel meter, the current panel meter, the process timer, the alarm selectors, the pump lights, and the metal enclosure. None of these changes significantly impact system safety but substantially reduce component count and wiring complexity.

That said, a number of additional system changes could be made to further reduce cost. For example, in actual operation, the only temperature of consequence is the HLT (hot liquor tank) temperature. Similarly, this is the only temperature that requires control. As a result we can eliminate the temperature probes, the XLR sockets, the PID controllers for the mash tun and boil kettle. The boil kettle will still need some control to allow increasing or decreasing heat input. This can be accomplished with a basic PWM (pulse width modulation) circuit that is adjustable in duty cycle via a simple potentiometer. This would directly drive the boil SSR.

Step 3: PID Modifications

Picture of PID Modifications

The selected PID controllers are quite inexpensive but they do not have the correct output to drive the SSR. As purchased the PID will have a relay output meaning that a signal generated by the PID will energize the coil on a 120VAC relay while we want to activate the SSR with a DC voltage. The good news is that the signal generated by the PID to energize the relay coil is a 12VDC signal and we can simply route that 12VDC signal out of the PID to directly drive the SSR. See the attached photos for details.

The first step is to open the case which is fairly easy, the front bezel and PCBs slide out once you depress the locking tab. Next locate the output relay using the connection diagram printed on the outside of the case or the user manual. Then desolder the 120VAC relay. Lastly we shunt the 12VDC trace to the output lugs so that we can access this signal outside of the housing. We then wire the output terminals on the PID to the SSR as if the PID was always SSR compatible. 

One final note is that you will need to configure the PID controller to reduce the cycle time to around 2 seconds which is often the minimum on relay output PIDs since rapid cycling of the mechanical relay will quickly cause it to fail. Having removed the mechanical relay and now driving an SSR with no moving parts we want the system to respond more rapidly.

If you select an alternate PID, you need to ensure your can drive the SSR or modify the controller to drive the SSR. Go!

Step 4: Component Substitutions

Picture of Component Substitutions

The following are guidelines when selecting components:

Burner Lights: The burner lights illuminate when the SSR and contacting relay are active. Meaning that the burner select switch is enabled to either the HLT or Boil and the PID controller is energizing the SSR. When this happens, the lights will have 240VAC across them so you need a light rated for 240VAC and they will illuminate. A 120VAC light will draw twice its design current and burn out quickly. Neon, incandescent, and LED lights for this duty are available. I recommend you head to your nearest electronics surplus store or pull from salvage equipment. Nothing fancy is needed. You could eliminate these but since it is handy to know when the big heaters are being made hot the lights are a nice to have. Keep them.

Keyswitch: A keyed switch isn't really needed, but it adds a cool factor especially if you need to turn two keys in unison to arm the system. Also a keyed switch will keep random passers-by from firing up your brewery, as long as you hide the keys somewhere. If you hide the keys somewhere you are sure to forget where you put them because hey, we're brewing beer here and you can't brew beer without making room in kegs for that beer by drinking beer. Make sure you have a second key made. Any keyswitch rated for 120VAC will work. No real current handling capacity is needed since the keyswitch just enables the main relay.

Burner enable switch: The important spec on this switch is that it have an off and two separate on states and be rated for 120VAC. An on-off-on toggle is a good cheap choice and is what I used.

Heater element receptacles: You will need to be sure that the plugs on the end of your heater element wires are compatible with the receptacles you have on your control panel but as long as everything is rated for 240VAC and 30A you can choose what you like. I went with locking receptacles to prevent pull out, but those are a little pricey. As you can see from the pictures I used 4-wire plugs and receptacles but only 3-wire is needed (2 hots and a ground). However I had the 4-wire parts lying around so...

PIDs: Go for it. You can do it. If you find a cheaper PID or have some sitting around you can likely mod them to work. SSR output preferred. The specifics will be up to you, feel the burn.

Pump Switch: All you need is on-off and capable of handling the voltage and current of the pumps. The pumps are not a big load nominally but since they are motors their start up current can be large. So oversize the switches here. Rate them the same as your pump receptacles for peace of mind. 120VAC and 15A on-off toggles are not that expensive.

Pump outlet receptacles: Just use whatever household 120VAC 15A double outlet you have sitting around. Failing that, buy the cheapest at your local big box store. Nothing fancy here. 

Temperature probe sockets: Use a socket that matches the cables on your temperature probes. Anything will work, no current capacity or special voltage requirements needed. XLR is used here to match the probes specified by Kal at The Electric Brewery.

Step 5: Designing the Enclosure

Picture of Designing the Enclosure

The pictured control panel uses laser-cut 1/8" plywood as the primary construction material. Holes for the PID controllers, the switches, lights, plugs, receptacles, and other penetrations are also cut with the laser. The laser-cut pieces comprise the front, top and bottom of the housing, with scrap plywood screwed to an internal frame to form the sides and back. The sides and back are thicker wood and are screwed together such that they form one U-shaped piece and the frame with laser-cut panels form the main piece that slides into the sides and back. See the exploded CAD view. Screws hold the two halves together and allow the box to be disassembled in the event that additional changes, repairs or work needs to be performed on the electronics within.

The thicker sides and back are cut slightly larger than the laser-cut panels and frame to allow overhang to somewhat protect the thinner wood panels from damage.

You will need to modify the attached laser cut files (PDFs) to match the components you choose. Particularly, the cutouts for the lights, switches, and receptacles may need to be changed. 

Step 6: Wiring

Picture of Wiring

The final step is to wire everything up. This is where attention to detail, a steady hand, and a ready supply of curse words can come in handy. Make sure everything is unpowered when you are wiring, be safe, and understand what you are doing. Releasing the magic smoke from inside electronic components is not a good way to reduce system cost.

A lot of the wire in the control panel is heavy duty to carry large currents and is thus hard to work with. When using terminal strips you may find that it helps to tin the stripped ends of the wires. Crimping on ring and spade lugs will be required so pick up a crimp tool when you buy your lugs. The attached pseudo-schematic gives you an idea of what you want to do. In the schematic, thick fat wires are heavy duty 10 gauge for the 30A heaters. The rest are drawn with thin lines and can use smaller wire like 20 or 22 gauge since no appreciable current will be carried. However, the wires for the pump switches and outlets are drawn in medium weight because they should be 14 gauge since the outlets are rated to 15A and you may be plugging things into these outlets such as pumps, fans or the occasional vacuum cleaner that may draw a significant current.

The terminal strips were converted into "Bus" strips by using short sections of solid copper wire that short the terminals together as you can see in the photo of the interior wiring. Be sure to use a heavy duty wire, in this case 10 gauge for the hot bus and might as well use 10 for the neutral bus.

Another method to cut down on the number of wires running around your enclosure is to use the ring or spade terminals to accept more than one wire to allow you to avoid running a single wire for each need. In the case of the PID controllers you can see in the wiring photo that I've daisy chained the hot and neutral wires at the spade lugs to cut down on wires.

Be sure to have a good single point ground for the heaters and the outlets. If your enclosure is metal, ground it too. Also grounding the housings of metal components such as the key switch or the toggle switches is a good idea. Bring these grounds to a single point, which in my case was a bolt that I put all the ground ring terminals on and tightened them together. You can see this bolt in the lower right of the interior photo.

Step 7: Final Thoughts

One additional detail that is different than the Electric Brewery is that the pictured setup uses a GFCI outlet rather than a copier cord with built in GFCI capability. More accurately, the pictured setup uses a 240VAC 30A GFCI breaker installed at the service panel to make the 4-wire dryer outlet that the control panel dryer cord plugs into GFCI safe. This GFCI breaker is an expensive item but vital to making the whole brewery safe. Do not skimp on this!

Be sure to double check all your wiring before powering up the system. When everything is checked and double checked, you should leave the control panel unplugged from the wall but plug all the components such as the heaters and pumps and temperature probes into the control panel and check to be sure that your kettles and other items are not accidentally shorted to the hot or neutral leads with a multimeter. With that checked, you can arm the system and do some testing and then some brewing. Good luck.


Jul_Lec (author)2018-01-12

Hi ! I'm an electrician from canada (qc) . Thank you to give us all this information to get a cheap cost control panel to make good beer every day !! But i have to advise you !! you can not legaly build a control panel in wood !! because if you have a electric probleme with your power device wood can burn :) evry thing is okay in your panel if you correct it with steel !!

Thank you

bryanshults (author)2017-11-13

Hi. Slowly collecting the parts and pieces to begin phase 1 of this build (BK control only). Wondering about the wood enclosure. Seemed reasonable to me, but have been seeing conflicting opinions about safety. Considering your rig looks worn and you're still answering questions about this post, I'd have to guess you have had no heat/fire/carstrophic failure issues. Any comments about your experience with heat generation of the SSRs and damage/impact to the wood enclosure?

Great post and guide! Many thanks.


jmengel (author)bryanshults2017-11-14

The wood enclosure does soak up spills and splatter, so gets more worn with use but otherwise has been fine. Keep it clear of the messy processes and you should be ok, it certainly isn't water tight. In terms of safety, definitely a good GFI breaker is needed with proper grounding where applicable. Never had a problem myself. Also, the heatsinks for the SSRs are outside the wood case and never get very hot in my experience. The failure mode we've had is with the PID controllers. All the original units have failed and we are now using a better quality unit only on the HLT with a simple PWM controller on the boil. Good luck!

bryanshults (author)jmengel2017-11-14

Great, thanks for the info. I opted to just go with Auber's SSR regulator as I'm just an extract brewer at the moment. Building your enclosure so that I can expand at a later date. My last question relates to the SSR/heat sink mounting. The heat sink I have is basically the same dimensions as the SSR; maybe a 1/16" excess on the long sides of the SSR. Curious to know how yours are mounted. I see the mounting holes on either end of the SSR cut out; does your sink or SSR have "ears" to use for the mounting screws? My current plan is to get a thin piece of copper sheet and make a plate to sandwich between the two pieces and leave it long and use that excess to tap some holes for mounting screws.

There's a lot in there; hope it makes some sense.

Thanks again.

carton132 (author)2017-05-11

Thanks for sharing this guide. The parts list and wiring diagram you've provided offer a level of context and detail that other guides are seriously missing! You've inspired me to build a similar system based around a Raspberry Pi and CraftBeerPi, mostly just swapping out a PID for the RPi. I also plan to simplify just a bit and start with only 1 heating element and 1 pump. Any tips for my plan before I start ordering parts? Thanks again for sharing!

whaug (author)2017-04-17

So I have my entire panel wired up and everything works just fine. PID's light up and read 21, All of my led indicators work when I switch them on. However, My pumps are acting a little weird. When I turn either one of my pump switches on it powers up both of my pumps. How do I seperate these from each other using the receptacle I have. (15 Amp/120 VAC) like the one shown.

KellanH (author)whaug2017-04-17

Did you remove the break away tab on your outlet?

MikeS544 made it! (author)2017-03-13

Forgot to add a image.

jmengel (author)MikeS5442017-03-13


MikeS544 (author)2017-03-13

Thanks for your guide! I was inspired by that and came up with my own build. Check it out here:

beerrab (author)2016-11-05

Hello, I like your Guide. It is very Clear and understandable. I would like to build my own control panel using your guide, but I have a question about using the Mash PID to control the mash pump for a HERMS. How would that change the wiring and would I have to use a different PID than the one listed?

Thank You looking forward the your answer!!!

jmengel (author)beerrab 2016-11-05

You would just wire the SSR output to energize the hot leg of 120VAC pump outlet instead of the black leg of the 240VAC for the heater element. For the relay, you'd wire the black and white wires from the pump outlet to the relay instead of the black and red. You would have to tune the PID but should be able to use any one suitable for the project to drive the pump instead of the heater. I think.

jblively (author)jmengel2017-03-09

First off, this is so awesome. I've sourced most my parts, just waiting on the PIDs to get here. I'm doing a HERMS as well, and I see beerrab's issue. In need 1 PID and SSR for the Boil kettle. I need to keep the HLT at a certain temperature, with another PID and SSR. Then you have the Mash PID, according to the diagram and the part list, there isn't an SSR for it. It's just sitting there in the diagram, relaying the temperature of the Mash. So, if I'm reading this right, if I added 1 more (for a total of 3 SSRs) I could wire the SSR output to the hot leg of the 120V pump outlet. Does that sound right? What kind of SSR would I get since it's powering just a 120 pump? Do I need to go through a relay for that or can I go directly from this new SSR to the hot leg of pump? Thanks so much.

jblively (author)jblively2017-03-09

Something like this? Using the SSR signal from the Mash PID to activate the SSR, when this goes through the toggle switch to the Pump #1 on the120 volt outlet to turn the pump on. So, if the Pump #1 toggle was off, even if the Mask PID was activating it, it wouldn't power up. So, you'd have to toggle on the switch to active the HERMS heating that's set on the Mash PID.

Or am I way off?

jblively (author)jblively2017-03-09

Or is any of that really even necessary? I mean, I kick the pump on. I set the HLT to a temp, and the mash recirculates. The power of HERMS is that the Mash can NEVER get hotter than the water in the I don't need to 'kick the pump off' to keep it from over heating..I just drop the HLT temp if I want to adjust the Mash Temp. As long as the pump is on, they should eventually equal each other.

Pay no attention to the above posts....these are not the SSRs you are looking for...

jmengel (author)jblively2017-03-10

My opinion is that you don't need to control the mash pump. You want as much recirc as you can get through the mash, and as you correctly state the mash will not exceed the HLT temp. I just leave the mash pump on and meter it down with a valve to prevent pulling too hard on the filter bed. The temp of the mash is shown to inform you when the mash has reached the temp desired as the settling time is much longer than that of the HLT. Meaning that if the HLT has just reached 77C the mash may take an additional 20-30 minutes to stabilize depending on the mash volume and pump flow rate.

In practice, my HLT PID failed recently and I swapped in the mash PID rather than buy another so I only have display of the HLT temperature. I just give a cushion to all brew times to allow the mash to reach temperature after the HLT has.

Good luck!

beerrab (author)jmengel2016-11-05

Actually In a HERMS set up you still need the HLT to keep temp the mash temp is controlled by the mash pump recirculating through the HLT with in a heat exchanger. In other words what I need to figure out is how to have the mash PID control the Mash Pump. which is in line with the Mash Tun and the HLT through a heat exchanger within the HLT.

Marekot (author)2017-02-24

Well, I had a few wired mixed up. Now as soon as I turn the key switch the GFCI breaker that I installed in my panel trips.

DennisK18 (author)2015-09-20

I was wondering what components would have to be switched out, and what to replace them with if I wanted to go with a 50amp service from my range top. I live in an apartment and don't have a dryer outlet. Is it as simple as switching out all the parts here that are rated for 30amp for those rated at 50amp? This would also allow me to use two elements at the same time. Would I end up having to wire it differently to operate both elements at the same time? If you have time to address these questions it would be much appreciated. Cheers!

jmengel (author)DennisK182015-09-21

Unless you plan to brew very large batches (two elements in one big kettle) or two batches back to back, meaning you will be boiling one while mashing another, I don't think there is much utility in going to 50A. If you have a 50 amp service in your apartment for the electric range, just change out the plug on the brewery controller to match whatever you have for your range and build the rest of the system as shown. I wouldn't try it at all unless the breaker for the range is GFCI.

To answer your question though, you would have to change the system significantly to operate both elements at once. The on-off-on setup currently specced does not allow both to be on and a pair of independent toggles would be needed along with changing out the main contactor and all shared wiring to handle 50A. Not too difficult but if it isn't clear to you then probably not something you want to jump into.

TomB189 (author)jmengel2016-04-10

I built a 50 amp setup (2 4500 watt elements) and don't do back to back batches or batches greater than 10 gallons. What I like about it is that it lets me get my brew session going much more quickly. I can heat up the mash water in the boil kettle while heating up the HLT at the same time. If I want to brew after work then I will fill the HTL and boil keggles to the right volume the night before and set the temperatures on the PIDs. When I get home from work I flip the switch, get changed, take the dog for a walk, and by the time I'm done with that I'm ready to pump the water from the boil kettle over to the mash tun and mash in. I love it.

The only thing I wish I had done differently was put a 5500 watt element in the boil kettle, as my volumes are 6.5 gallons for sparge, while the mash requires 6.5 + grain absorption for mash, and the temperature needs to be significantly higher to account for heat losses to the grain and to the mash keggle. I batch sparge, aiming for equal volumes from the batch and the sparge, so I get 13 into the boil kettle, 12 post boil, 11 into the fermenter, and 10 into 2 corny kegs. I don't worry about grain to water ratio, just aim to have 6.5 in the boil kettle after the mash, and it's worked for me.

The cost of the control panel was only slightly more expensive (1 extra switch). The real cost was that 6 gauge wire is expensive to run from the breaker to the outlet, and that I needed to use 3/4" conduit which is much more of a pain in the ass. On the flip side, it's an extra $60 for wire. 50 amp spa panels are cheaper than 30 amp CFGI breakers. If you're already going to these lengths then just bite the bullet. I prefer batch sparging anyway, that's why I do it, but if cost is a concern, I'd build a 50 amp setup with only one pump and batch sparge until I could afford to get a second pump for fly sparging. My beer tastes great and I get great efficiency, so I'll stick to batch sparging.

wawa30 (author)TomB1892017-01-30

What relays did you use for the 50 AMP Build?

TomB189 (author)wawa302017-01-30

I don't really remember but I got them from auber instruments, along with the box, heatsink, switches, ssrs, pids. and rtd temp sensors. I think that I used the 2 pole, 40/50 amp, 120V coil relay wired to the on off key switch, and the 2 pole, 30/40 amp, 120V coil relay wired to each element. I was going to add some pictures of my control panel, but nothing happens when I click the "Add Images" button.

DennisK18 (author)jmengel2015-09-22

Sorry, my misunderstanding. I thought this setup only provided power to one element at a time. As long as I have power to the HLT and the BK simultaneously that works fine. Yes, two elements in the kettle I'd be using would be overkill.

My only worry, using the 50amp service, if there was a fault in the 30amp system, it wouldn't trip the breaker, isn't this correct?

Thanks for the quick reply.

jmengel (author)DennisK182015-09-24

The setup only powers one element at a time. The on-off-on switch only allows one element relay to be energized at a time. Replacing the on-off-on switch with two independent toggle switches would allow both element relays to be on. However you would need to alter the internal wiring and components to handle the load of both elements being on at the same time.

A fault in the 30A system would still trip the 50A breaker, but not before potentially damaging the 30A components and wiring. With a 30A breaker and components specced for 30A, theoretically a fault would not result in damage (melted stuff).

Hubotu (author)2017-01-17

Nice site and box. What is the risk in using a 220V 3 wire supply and running the neutral connections to ground? Also, you referenced a PWM circuit to regulate the power to the HLT . How hard is that and where would one (non-EE) figure out how to incorporate that into the controller.

jmengel (author)Hubotu2017-01-18

You can't get GFCI protection with 3-wire. You need a separate ground and neutral. So the risk is death.

I did build a PWM circuit with a potentiometer to dial in the power to the boil kettle in a manual fashion, I still use the PID controller to automate the temperature control on the HLT. It is easier to use a proportional control SSR for the boil rather than build your own PWM. Here is an example:

Hubotu (author)jmengel2017-01-18

Thanks for your reply. The link is very cool - they have lots of things geared specifically to this area of interest and the descriptions are excellent.

MikeS544 (author)2016-11-25


Could I use any of these? Does it make a difference? Thanks!


jmengel (author)MikeS5442017-01-18

Either would work as long as they are rated for the current demand.

justonian (author)2016-12-27

Why do you spec out 60A ssr wouldn't 40A like the ones in Kals control panel suffice?

jmengel (author)justonian2017-01-18

I used 60A SSR's because that is what I had on hand. You are correct that 40A ones would work fine.

AaronS269 (author)2016-11-25

Question about your GFCI configuration. Since it's a 240V GFCI wouldn't the imbalance created by running, say, a 120V pump (that only uses one hot and neutral) immediately trip it?

MikeS544 (author)AaronS2692016-11-25

Why would it? It is measuring the difference between current in / current out.

nbertoli (author)2016-11-15

What are the dimensions of your enclosure?

jmengel (author)nbertoli2016-11-16

250mm tall x 300mm wide x 150mm deep

fafrd (author)2016-10-25

great site - thanks for making the effort.

One quick question on these cost-effective Chinese PIDs: do they support a manual mode for the strength of the boil like the newest PIDs from Auber: ?

Also, can anyone post the link to the English manual for these PIDs?

Thanks again

MikeS544 (author)2016-10-03

I'm getting ready to build this thing! Thanks
for the helpful information here!

I saw that the elecricbrewery uses a 7amp fuse
to protect the smaller cables in the control panel. Why is this not needed in
your setup? Sorry, I’m no electrician. :-)

jmengel (author)MikeS5442016-10-03

Fuses are a good idea, but my build was focused on low cost, which means low part count. Feel free to include a fuse.

rmeisch (author)2016-08-31

Did I miss something or should there be a transformer to covert the 220v to 110v for the pumps? Or, does this design assume that the pumps can be powered by 220v?

jmengel (author)rmeisch2016-09-01

You missed something. 220V is created by the two "hot" 110V lines (red and black) 180 degrees out of phase to each other. So by taking one of the "hot" 110V lines relative to neutral (white), you get 110V. No transformer needed.

rmeisch (author)jmengel2016-09-01

Thanks for the response!

mikehoover (author)2016-03-03

Trying to troubleshoot my build of this. I checked the output of each heater receptacle. When the PID activates the SSR I get around 240 volts on each one. If the PID has not activated the SSR, I get just under 50 volts on one and around 75 volts on the other. As this is happening, the lights that indicate the heater receptacles are active are bright when the PID activates the SSR, and dim when not. So there is always some voltage unless the toggle switch if OFF. So this causes the heating coil to continually fire albeit at low voltage when the SSR is not activated. This causes the temperature to creep steadily past the set point. Any ideas why? Thanks!

CraigH57 (author)mikehoover2016-04-04

Did you ever get this resolved? Are you sure the heater is actually on/hot when the SSR is not enabled? SSR's, by their standard operation, will leak voltage across the AC terminals but not much current. I had the same issue you did, I was seeing almost the exact same voltages you were reading and a dim lit light. The leak through current is likely enough to power a small light as it probably only requires milliamps to illuminate. I had a scrap desktop fan I wired in to simulate a load on the SSR and the voltage leak went away, there also wasn't enough current to turn the fan. So in short, as soon as there is a load on the SSR, you should get the correct readings.

mikehoover (author)CraigH572016-04-04

I seem to have had no problem to start with LOL. I got a response from the Electric Brewery site saying that although there is a voltage leak from the SSR, there is no current, therefore the coil is not on. I tested my system out a few more times and everything seems to be operating as expected. The temp creeping that I had seems to have stopped after I ran the auto tune process on the PID.

jmengel (author)mikehoover2016-03-03

Hmm. Hard to say without having a schematic and list of your components. What relays and SSRs are your using? If wired as shown with DPST relays you shouldn't have any voltage when the SSR is off. If your lights are dim and the heater is pulling some current with the SSR off then your SSR is not really off or the wiring is such that there is an alternate current path when the SSR is off. Are you using GFCI? Have you checked if there is a voltage on the kettle itself? Careful.

mikehoover (author)jmengel2016-03-04

Thanks for your reply. I am scratching my head here. I have wired the panel per your schematic. I used the relays you have listed, the PIDs and SSRs from Auberins that The Electric Brewery folks use as well as the LED lamps they use. Not sure how there is the low voltage when the PID turns the SSR off, and full, proper voltage when the SSR is on (the little red LED on the SSR is on too, only when the PID turns the SSR on.) So when the PID sees it hits the target temp, it turns the SSR off (red LED light on SSR goes off). But measuring voltage in the heater receptacle reveals around 50 V on one and around 75 V on the other receptacle (SSR LED is not lit), which is why I the temperature continues to rise in the kettle, albeit slowly. When the toggle switch is in the OFF position, there is no voltage measured from either heater receptacle. Thanks for your help! It is much appreciated.

jimmiek (author)2016-03-25

Just to let you know, some of us are not engineers! ;), some of us are electronix illiterates! .... So what does it mean here? "Lastly
we shunt the 12VDC trace to the output lugs so that we can access
this signal outside of the housing. We then wire the output terminals
on the PID to the SSR as if the PID was always SSR compatible." It's a foreign language to me, although I'd like to be able to understand what you're getting at. Is there a possibility that a PID and SSR are available that I could use instead of trying to do something I know absolutely nothing about?

I would just like to build a simple control box with a couple of switched 20A outlets, and a switched 240v 4500W temperature controlled heating element for the HLT. The reason I want everything switched is in case of a malfunction - such as a hose slipping off the barb and spraying hot water all over creation!


CraigH57 (author)jimmiek2016-04-04

Yep, you can purchase a PID with SSR connections already in place. Take a look at

CraigH57 (author)jimmiek2016-04-04

Yep, you can purchase a PID with SSR connections already in place. Take a look at

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