Electric Brewery Build Update – How the electrical design was completed

Electric Brewery Introduction

Here I will document some detail and progress on the electrical component of the 2HL brewhouse build.

There are quite a few well documented electric brewery panel builds on the web. This one will be different as it has a more industrial design inline with what I see in my day to day work as an engineer. The electrical design intent of this brewery was to build a panel such that it could ultimately be run on 3 phase power supply to allow all heaters to operate at the same time(approx. 120A) however initially would be set up as single phase. Running single phase is easier for testing at home and the automation will be set up to only allow certain combinations of heaters at any one time to limit current draw to 60A. When eventually installed in a factory and wired to a 3 phase point, all heaters can operate at the same time and still allow for operation of coolroom, chiller, lighting etc.

I/O List

The electrical design process started with an input/output(IO) list generated from the piping and instrumentation drawing(P&ID).  The list is summarised below:

Brewery Electrical IO List

Brewery Electrical IO List

The IO list identifies the required number of IO modules both digital and analogue required on the PLC, the physical point to wire to on the PLC, the tag numbers used for programming and also gives an idea of the loads to be spread between the three phases. This list also includes items planned for future installation so that the wiring, hardware and load splitting can all be taken into consideration at this early design phase. After completing this I was able to select the correct PLC specification and any additional plug in modules. More information on the PLC will be added to a separate post on automation.

From here a load splitting table is created to try balance the loads a best as possible assuming all are being used simultaneously. In reality they wont unless double batching. My table:

Brewery Electrical Drawings

Now that the line loads have been determined, a set of electrical line drawings was generated. I enjoy designing so had a go at these myself and then had them checked over by a couple of electrical engineers. Having built two similar panels on other breweries in the past, this process is getting easier and great fun to learn. This build required a total of eight drawings, a sample of one of the drawings showing some of the heaters is shown below:

Electric Brewery Panel Drawing

These drawings identify all the electrical hardware required as well as the required cable sizes. After completing a set of electrical line drawings then the panel layout drawings were required. This sets out the amount of space required for all the hardware. This panel will be quite tight and if doing it again I would have used a slightly bigger(wider) panel to allow space for future items to control the mill and fermenters. This panel was a standard size and already in stock when I needed it so it was used. The panel layout drawing for this build is shown below:

electric brewery panel build drawing

Electric Brewery Panel Pictures

Now with a complete set of drawings the required components and cables are slowly compiled. The panel gear tray is now mostly assembled ready for installation into the field panel.

Brewery electrical panel pic

Brewery electrical panel pic

The gear tray is now ready for installation into the field panel and terminate the field wiring.

electric brewery panel build

Electric Brewery Information

With the brewery being full electric, the panel design is quite simple as electric heaters make up 80% of the process. For the heater circuits each of the three phases enter the panel and into an MCCB. From here the loads are split and run to a solid state relay(SSR) via a fuse. On this build I have used SSR’s instead of mechanical contactors since many will operate on PWM. Since the panel is enclosed and I don’t plan to install a fan initially, I have oversized the SSR’s by minimum triple. For example the HLT heaters draw between 9 and 17A and all use 40A SSR’s. The future 5kw kettle heaters will draw approx 20A so I have used 125A SSR’s.

The hot liquor tank(HLT) elements will be a simple on/off in any combination of the three elements. All the other heaters will be used with pulse width modulation(PWM) from the PLC to allow the power levels to be varied from 0-100%. These can then be used on a PID control loop in the automation which will be required for the HERMS system and also the mash tun heat belts. The kettle element will likely be used to run at a certain power% to achieve the required boil off rate.

The kettle is initially set up on gas however in future will be adding 2 x 5kW electric elements to make it an all electric brewery. Once I decide on these elements I will look at getting them custom rolled to still allow a good whirlpool. To make life easier in future the brewery has been pre wired with the required cables and hardware for these heaters and the loads split up to suit.

Check out the blog page to see if there have been any further electric brewery updates.


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