If you're thinking about doing an electric build, I highly recommend you visit The Electric Brewery. This is a fantastic resource where Kal shows you in-depth step-by-step details on how to create his electric brewery setup which is among the finest out there. HomeBrewTalk.com is another great source of information with a dedicated electric brewing forum. Many of the members there were a great help in putting together my setup.
Building an electric brewery setup isn't exactly cheap, but this instructable will show you how to build a basic combo hot liquor tank (HLT) & brew kettle (BK) setup as simply and inexpensively as possible--the entire setup can be assembled for around $300, a third of which is setting up the 240V supply outlet. The heating in this case is done with a 5500W hot water heater element powered by a 240V electic supply. This setup is also easily upgraded by adding a second kettle in the future.to have a dedicated HLT and BK.
Step 1: Parts list
I'm going to list the bulk of the parts needed here. There are a couple small things like machine screws, nuts, etc... I don't list because I'm assuming that if you think you can handle this project, then you have a coffee can full of them sitting around somewhere. Aside from basic tools like a reciprocating saw, drill, vice, and so forth, you will need a set of step bits for drilling holes in the keg. I used these harbor freight bits and they worked out just fine. If you have the fancy punches, more power to you, but they're not required.
Parts list--The control panel
The control panel is the center of the electric brewery. It will plug into your electric supply, monitor the water/wort temperature, and control the heating element. While we will be building a simple version with control for a single element, these can be as complex as you want with alarms, timers, switches, and the like.
PID temperature controller SYL-2352, $44.50: The PID is the ‘brain’ of your electric brewery. This reads the temperature and controls the heat output via the SSR. This particular model is highly regarded and can be run from a 120V or 240V electric supply.
Weldless RTD temperature probe PT100-L50M14, $33.95: The RTD temperature probe is what is responsible for actually measuring the temperature sent to the PID. This particular item is for a weldless fitting. You can get it in either a 2 or 4" probe, but having gone with a 4" I feel a 2" would be better if mounting directly on the kettle wall.
Panel mount connector for RTD sensor RTDCON, $3.75: A panel mount connector allows you to disconnect the probe from both the control panel and kettle.
40 amp SSR with heatsink, ~$12: The SSR turns allows is the switch that allows electricity to pass to the element and is turned on/off by the PID. They can be found fairly cheaply on eBay.
Panel mount fuse holder, ~$3: At only $3, it's a worthwhile investment to protect the expensive PID with a cheap fuse. Make sure you get one designed for 30mm fuses to ensure easy to find local replacements.
Thermal compound, ~$1: This will help heat transfer between the SSR and the heat sink. If you already have some that works too.
2-space Eaton load center #BR24L70SGP, $12.47: The load center will serve as the housing for the control panel. By using a load center it already includes all the lugs and terminal bars needed for the main power connections, and it's cheap.
30-amp 2-pole flush-mount outlet #621336, $5.29: This is the outlet the kettle will connect to.
3/4 in. twin-screw clamp connectors 5 pack #20512, $3.82: Connectors to secure electric supply to control pannel. Also used to secure wire to circuit breakers, spa panel, and outlet if installing new supply line.
0.5 amp fast blow fuse 5 pack #AGC-1/2, $1.68: Fuses for fuse holder.
Petra 4-wire 10' dryer cord #90-2028, $19.35: Wire and plug that will connect control panel to electric source. If using a different outlet make sure you get a cord that will fit the proper style. At 10' it's long enough to cut a couple feet off to use where 10G wire is needed for wiring inside of the control panel.
J-B Weld 8265-S Cold Weld, $4.98: Used to secure heat sink, kettle cover plate, and just an all around useful thing to have.
25 amp DPST toggle swtich #S331R, $12.04. Without a switch to completely cut power to the heating element, one leg will always be hot. This is an okay practice if, just exercise caution whenever you have the kettle plugged in. You may want to add a toggle switch to completely disconnect power to the element from the control panel. It's something I may still go back and do at some point, I'm really only skipping it because the test button on the line cord functions as a kill switch for me. When installing this switch, it is wired in between the SSR and the kettle outlet in the control panel.
Parts list--Electric supply
The electric kettle is going to need a 240V power source to plug into. At full power a 5500W element will pull somewhere around 24-amps, so it should be protected with a 30 amp breaker and wired with 10G wire or thicker. It should also be GFCI protected similar to outlets in a bathroom or kitchen for safety. The problem is high amp GFCI breakers are very expensive. The cheapest route is to use a spa panel designed for hot tubs that comes with a 50 amp GFCI breaker far cheaper than you could buy the breaker alone. Another option is a line cord that has the GFCI protection built in. This is the route I went because I found one for $75 on ebay, but they are usually much more expensive. I opted for this since it will be easier to bring with me when I move. In most cases you are going to want to install a separate outlet for the kettle. If you're not familiar with electric wiring, do a bunch of reading and ask questions to someone who knows their stuff. Don't try anything unless you feel comfortable with it.
My setup runs entirely on 240V using three wires (two hots and a ground). Given the option, it's better to go with a 4 wire setup (two hots, a neutral, and a ground) as you can supply 120V by connecting to one of the hots and the neutral. It offers more flexibility if you wanted to use the outlet for something else or add other components like pumps that utilize 120V. My line cord doesn't carry a neutral, so that was my limiting factor.
30-amp 2 pole breaker, $8-12: Assuming you have 2 spaces open in your circuit breaker, you need to install a 30 amp breaker to supply the outlet. You need to get the proper breaker for your brand of panel. In my case I'm supplying from a Cutler-Hammer BR type panel.
10/3 NMB wire, ~$1-2/ft: This is the wire that will run from your breaker to the spa panel and from the spa panel to the outlet. I had some laying around so I don't have an exact price on it. You may be able to find a local electric supply shop to get your wire cheaper than at home depot. I use a place that charges a per foot price based on 1,000 ft rolls regardless of how much you buy, but YMMV.
30-amp 4-wire flush mount outlet #918137, $7.49: Outlet for control panel connection.
2-gang metal box #443497, $1.02: Box to house the outlet.
1-gang square 30-50 amp receptacle cover #338974, $2.14: Cover plate for outlet
GE 50 amp GFCI spa panel #UG412RMW250P, $49.00: Cheapest way to add GFCI protection.
Parts list--The kettle
These parts, along with the temperature probe, are installed kettle side. If you wanted a separate BK and HLT then you order two sets of these (plus an extra RTD probe).
PETRA 90-1024 3-wire 30-amp dryer cord, $11.58: Cord with plug to connect kettle to control panel.
Camco 02963 5500W 240V heating element, $23.91: Heat source for the kettle. This one puts out a LOT of heat.
1-gang steel city handy box #421405, $1.61: Box of kettle wiring.
Raco handy box cover plate #744425, $0.50 x2: Cover plates for wiring box. Order two.
PVC pipe fitting ring
1" stainless locknut with O-ring, $9.00: Nut to secure heating element. Difficult to source part.
1" silicone O-ring, $0.85: Doesn't hurt to have an extra and shipping is flat rate.
Parts list--Sight Gauge upgrade
Sight gauges are extremely useful for quantifying volumes and for less than an extra $30 can be installed in the same mounting hole as the temperature probe. Bargainfittings.com is flat rate shipping, so might as well make use of it. If you are going this route, then replace the weldless RTD probe from Auberins with the 4" x 1/4" NPT probe. The 2" probe will be too short if connected through the sight gauge T.
Weldless thermometer sight gauge kit, $25.95: Sight gauge from the top and thermometer connection via the side.
1/2" NPT to 1/4" NPT stainless reducing bushing, $3.00: To connect 1/4" NPT probe to 1/2" NPT sight gauge T.
Total Cost Estimates
Control panel: $140 + tax/shipping
Outlet: ~$75 + tax
Kettle: $53 +tax/shipping
Optional sight gauge: $29
Grand total: ~$300 + tax/shipping