50A Electric Brewery Control Panel for back to back batches
This control panel is available in pre-built or kit form through our shop.
These wiring instructions are for our 50A Electric Brewery Control Panel for back to back batches for countries where the mains power has both 110-120V and 220-240V available such the United States, Canada, Mexico, most of the Caribbean / Central America / South America, Japan, and Taiwan.
A single element is still used in the boil kettle and hot liquor tank, but both may now be run at the same time allowing you to boil one batch while heating water for the next (or for cleaning/heat sanitizing the chiller).
Need more power or something custom? Our panels can be interlocked with optional modular booster panels to increase capacity as you grow. Contact us for details.
FAQ
When would I want a 50A back to back control panel?
Our standard 30A control panel is capable of running one 5500W element at time. It does not have the power capacity to run both the boil kettle and hot liquor tank elements at the same time. If brewing two different batches immediately one after the another, time is saved with this back to back panel as it allows both elements to run at the same time so that you can heat up strike water in the hot liquor tank for the second batch (or for cleaning/heat sanitizing the chiller) while the boil kettle is used to boil the first batch. Note that if you are interested in back to back batches to brew more of the same beer, it makes more sense to use a 50A control panel for 30+ gallons and brew it all at the same time instead of brewing two batches back to back.
How much beer can I brew with the 50A back to back control panel?
We recommend that the 50A back to back control panel be used for batches up to and including 20 gallons in size. While larger batches can always be brewed, you may find the the time to heat water or bring wort to boil to be overly long.
Are there any downsides to using the 50A back to back control panel?
Cost is the only downside. 50A components and wiring are more expensive than similar 30A rated items. Unless you want to consistently brew back to back batches, we recommend sticking with the original 30A control panel design.
Can I use this control panel to brew less than 20 gallons?
Yes. 20 gallons is only the recommended maximum to ensure reasonable heating times. Smaller volumes simply means faster heating times.
What changes are needed to upgrade from the standard 30A control panel to the 50A control panel for back to back batches?
Some of the 30A devices (and wiring) in the control panel are upgraded to 50A. The 30A standard dryer outlet is replaced with a 50A stove outlet. The single 3-way ELEMENT SELECT switch is replaced with two separate ELEMENT ON/OFF switches. See below for complete details on the changes required.
Are instructions available for countries that run at 220-240V?
Yes. See 50A Electric Brewery Control Panel for back to back batches (240V only, for international use). Kits with parts are available too in our shop.
Could I combine the 50A control panel for 30+ gallons and this 50A back to back control panel to brew 30+ gallons back to back?
Yes, but that would require a 100A control panel. 100A parts are considerably more expensive and harder to find as they are specialized (not standardized). Devices above 50A typically need to be hard-wired which itself introduces complexities and other concerns. Need more power or something custom? Our panels can be interlocked with optional modular booster panels to increase capacity as you grow. Contact us for details.
Do I still need to use a ground fault circuit interrupter (GFCI)?
Yes. A GFCI is required for safety reasons. In most cases this will be done with a 50A/240V 2-pole GFCI breaker in the electrical breaker panel. For more information on GFCIs see STEP 1: Supply power of our Control Panel build instructions.
Do I need a larger enclosure?
No. In the back to back control panel the single 3-way ELEMENT SELECT switch is replaced with two separate ELEMENT ON/OFF switches such that the heating elements may be controlled independently. On the bottom is a beefier 50A power input receptacle. There is more than enough room in the standard 16x16x8" enclosure for both. See above for a picture of the recommended layout.
Can a buy a control panel kit that includes all the parts I need already included?
Yes. We can supply control panel kits for any country including those where only 240V is available (outside North America). We can even pre-punch the enclosure for you to save work. See our shop.
Can I buy this control panel completely assembled and tested?
Yes. Like our standard 30A panel the enclosure is professional cut and painted to our specifications and then wired, and tested. See our shop.
WIRING/PART CHANGES
Follow the wiring diagrams below.
If you're new to wiring we recommend you read our instructions for our standard 30A control panel build as we present some general wiring concepts, hints, and tips.
POWER CORD / SUPPLY POWER
A 50A 4-conductor stove power cord attached to a Locking Grounded California-Style connector (125/250VAC, 50A) is used as the power cord: 
The stove cord has 4 conductors (2 HOTS, 1 NEUTRAL, and GROUND) and a NEMA 14-50R plug on the end. Conductors must be at least 6 ga for the two HOT lines and at least 8 ga for NEUTRAL and GROUND. You will need to install a 240V/50A circuit in the house terminated with a NEMA 14-50R receptacle on the wall to power the control panel. The power cord plugs into this receptacle which looks like this: 
This circuit should be wired to a 50 amp 2-pole GFCI breaker in the electrical breaker panel using the correct size wire between the two (6 ga wire by most electrical codes). The breaker must be 50 amps and not larger in order to protect the 6 ga wiring in the control panel.
Note that stoves typically come in 40 and 50 amp varieties with 40 amp being the more common of the two. In most houses stove circuits will only be 40 amps (typically a 40 amp breaker in the panel and 8 ga wire) since home builders do whatever is cheapest. 40A is not enough. The circuit must be able to deliver 50 amps for this 50 amp control panel. The actual receptacle you plug the stove into is usually rated 50 amps even for 40 amp circuits (since the plug is the same) but the wiring in the wall and the breaker in the panel itself will only be rated to 40 amps. If you're wiring up a new stove outlet make sure to tell your electrician that you require a 50 amp circuit, not 40 amp.
POWER INPUT
The power in receptacle and relay are changed to handle the larger 50A (resistive) load. 50A relays are difficult to find so a contactor is used instead. A relay and contactor (the terms are often used interchangeably) work the same way but contactors are generally rated for higher power. Note that a contactor rated for 40A inductive load (as presented by compressors in air conditioners or similar) is able to drive a 50A resistive load as presented by our heating elements. So if you find a 40A "inductive" contactor it's likely ok to use at 50A "resistive". Confirm that the model you intend on ordering can support 50A "resistive". Some of the 10 gauge wire is replaced with 6 gauge to handle the 50A load. Any ring terminals or connectors (if used) for connecting the 6 ga wire must also be rated for at least 50 amps.
Part changes as compared to our standard 30A control panel build:
(Qty: 1) 2 pole 50A (resistive) 240VAC contactor with 110-120VAC coil
(Qty: 1) Locking Grounded California-Style receptacle (125/250VAC, 50A)
(~1 foot) Black 6 gauge type T90/THWN/THHN wire
Wiring diagram (changes as compared to our standard 30A control panel build are shown in yellow): 
GROUND
The ground wire from the power input receptacle is increased from 10 to 6 gauge. To allow enough room on the enclosure ground post for all these ground wires we recommend using a 10 terminal ground bar on the back plate. Make sure to connect the door and enclosure ground posts to the ground bar as well. Any ring terminals or connectors (if used) for connecting the 6 ga wire must also be rated for at least 50 amps.
Part changes as compared to our standard 30A control panel build:
(Qty: 1) 7-10 terminal 50A ground bar (optional)
(~2 feet) Green 6 gauge type T90/THWN/THHN wire
Wiring diagram (changes as compared to our standard 30A control panel build are shown in yellow): 
VOLT AND AMP METERS
There are no changes to the volt and amp meter wiring. As per the standard 30A control panel build wiring instructions, make sure to adjust the DC power supplies to +5VDC or slightly below before connecting to the meters as otherwise the meters may be damaged. 
PUMPS
There are no changes to the pump wiring. 
PID CONTROLLERS
There are no changes to the PID controller wiring. 
TIMER AND ALARMS
There are no changes to the timer and alarm wiring.
Timer and alarm wiring diagram if using the newer JSL-74A timer:
Timer and alarm wiring diagram if using the original Eagle B506-5001/Omega PTC-21 timer:
HEATING ELEMENTS
The 3-way ELEMENT SELECT switch is replaced with separate Boil Element and Hot Liquor Tank Element on/off switches so that the elements can be controlled independently. Some of the 10 gauge wire is replaced with 6 gauge to handle the 50A load. 30A fuses are added to protect the 30A element receptacles and wiring. Why? On the standard 30A control panel the 30A circuit breaker in the electrical panel wall protects the 10 ga wiring so additional fuses are not required. With this 50A panel the 50A circuit breaker in the electrical panel protects the 6ga wiring but we now need to add protection for the smaller 10ga wiring between the contactors and the kettles (both inside the panel and out). Any ring terminals or connectors (if used) for connecting the 6 ga wire must also be rated for at least 50 amps.
Part changes as compared to our standard 30A control panel build:
(~2 feet) Black 6 gauge type T90/THWN/THHN wire
(~2 feet) Red 6 gauge type T90/THWN/THHN wire
(~2 feet) Black 10 gauge type T90/THWN/THHN wire
(~2 feet) Red 10 gauge type T90/THWN/THHN wire
(Qty: 4) 30A 250V fast blow fiber fuse
(Qty: 2) 30A 250V 2-pole fuse holder
(Qty: 2) 2 position maintained selector switch, 1 normally open (NO) contactor, 10A/240VAC
Wiring diagram (changes as compared to our standard 30A control panel build are shown in yellow):
Note: With some relay/contactor brands you may find it difficult to fit 6 gauge and 10 gauge red wires in the same screw hole at the top input #2 on the HLT relay/contactor. Do not under any circumstances trim back strands of the wires to make them fit! Instead, use a 50A power distribution block. Our control panel kits include this extra part (when required). Simply attach the large 6 ga wire from the POWER IN CONTACTOR into the big end of distribution block and then two 10 ga wires out the other end that lead to the BOIL and HLT relays/contactors.
SAFE START INTERLOCK
The power in receptacle and relay were changed to handle the larger 50A load as described previously. The 3-way ELEMENT SELECT switch is replaced with separate Boil Element and Hot Liquor Tank Element on/off switches.
The POWER KEY switch was previously wired directly to the POWER IN RELAY coil (per the POWER INPUT wiring diagram above). This wire must be removed otherwise the interlock feature will be bypassed and the control panel will power up regardless of how the three other switches are set.
Previously the WORT PUMP and WATER PUMP switches only had their normally open (NO) contactor wired up (per the PUMPS wiring diagram above). We are now adding a normally closed (NC) contactor beside the existing contactor. Only the new wiring is shown here. The existing wiring does not change.
Wiring diagram (changes as compared to our standard 30A control panel build are shown in yellow):
Nothing else in the control panel changes since the rest is all low current 120V. How the panel operates remains identical. You may now simply run both heating elements at once.
Once completed, make sure to follow our control panel setup instructions.
Interested in building your own? Kits are available in our shop.
