OK, to educate myself more about 3 phase power and how much/many elements/breakers/SSR's I would need in my modular brewery concept, I have been doing some reading and calculations.

For those interested here is some of what I have compiled so far...this is the dumbed down version, so I might be missing something- Feel free to chime in.

1st: You can wire heating elements in a Delta configuration or a Wye configuration. My panel is Delta so I'm using the Delta formula. I don't know if this is a requirement.

The formula to calculate Delta Line Current is:
**Total Watts/(sq rt 3)(Line voltage)= Line Current (Amps)**
Total Watts/(1.73)(Line Voltage) = Line Current (Amps)

To calculate Single Phase is easier;

Total Watts/Line Voltage- Line Current (amps)

Jumping ahead a little- The big reason for sizing the elements is to A) make sure you have enough room in the panel box; and B) have enough power to get the wort to a boil in a reasonable amount of time.

A formula for figuring how long to raise the temp of water is;
**((4.2 x Volume in Liters x Temp in Celcsius)/3600)/Total KW = Time**
In my case how long will it take to heat 190l (50gal approx) 30 deg C (160deg F to 210deg F)?

It takes 8,000 watts (8kw) approx 50 minutes to raise 50 gal of wort from 160 deg F to boiling temp (discounting Altitude) of 210 deg F.

It takes 12,000 watts (12kw) approx 33 minutes to raise 50 gal of wort from 160 deg F to 210 deg F.

It takes 16,500 watts (16.5kw) approx 24 minutes to raise 50 gal of wort from 160 deg F to 210 deg F.

It takes 18,000 watts (18 kw) approx 22 minutes to raise 50 gal of wort from 160 deg F to 210 deg F.

Now to compare power requirements. My line voltage is 240 3 phase. I have a 200 amp panel.

8,000 watts requires 18 amps 240v 3 ph; with a 120% margin the breaker (and SSR) would need to be 22 amps

12,000 watts requires 27 amps 240v 3 ph; with a 120% margin the breaker (and SSR) would need to be 33 amps

16,500 watts requires 38 amps 240v 3 ph; with a 120% margin the breaker (and SSR) would need to be 45 amps

18,000 watts requires 41 amps 240v 3 ph; with a 120% margin the breaker (and SSR) would need to be 49 amps

If I understand it correctly, a 3 phase Solid State Relay acts like 3 single phase relays with one contactor/switch. Common 3 phase SSR's are rated 10,25, and 50 amps.

P-J would know better but it seems like one 3 phase SSR would run three single phase heating elements.

It appears for the power draw, the sweet spot is around 12,000 watts or 3- 4,000 watt elements for 3 phase. Comparatively on a single phase setup with 240 volts the same 12,000 watts would require a 50 amp breaker and with a 120% margin the minimum breaker would be 60 amps.

This might work?
On another forum the numbers compared well with the experiences of a brewer with a 60 gal 8,000 watt- 2 elements 240v system. He said it took him about 45 minutes to get the wort to a boil from the sparge.

These numbers don't account for losses.

So potentially a brew day could look like:

Time to get to mash in: 30 minutes with tankless water heater at 140 deg F

Mash: 90 minutes

time to mash out: 15 minutes

sparge: 45 minutes

time to get to boil: 30 minutes

boil: 90 minutes

chill: 30 minutes

5 1/2 hours total. That's about what it takes me now with brewing a 5 gal batch on the keggle 3 vessel.