Bitcoin Forum

What is the difference between single phase and three phase electricity, specifically 208 V and 240 V? Does it affect the performance of the machines in any way whatsoever?

I can also get 218 V single phase, would this be okay?

Yes, any of those voltages will be fine.

3-phase will work fine, but it is not necessary. All you miners PSUs will be single-phase input power. All single-phase devices can be supplied from a 3-phase panel.

If your mining operation is large enough, 3-phase power is handy for large fan motors or large air conditioners. Once electric motors exceed 5 HP, single-phase operation is difficult, expensive and silly.

I always pick the highest voltage when I have a choice. It relaxes the wire gauge requirement slightly or reduces the power losses and heat produced by the conductors. Also, PSUs typically run a bit more efficiently closer to the top or their voltage range.

3-phase power has 3 Lines each 120 degress offset from their adjacent Line.
They are typically labled, Line1, Line2 and Line3, but lets call them A, B and C.

When you connect your power supply using any two lines, that is a single-phase configuration. You can use any of the following;
In a Wye circuit
A, B = 208
B, C = 208
C, A = 208
Any pair will give you the higher voltage of the circuit rating.

You can tie between any Line and Neutral (N) to get 120V.
A, N = 120V
B, N = 120V
C, N = 120V

If you order the 120/240 service, that is a Delta circuit, any two Lines will give you 240V, A transformer is typically used to provide a secondarily derived Neutral. It is often cheaper to buy this transformer than to spec the Wye and have to pay for the 4th wire from the utility transformer to supply the neutral; especially when 90% of your load will be at 240V.

 The best information you can give the utility and your electrician is the nominal power you need to supply. Just check our miner specs for power, multiply by the number expected, then double it. They normally don't charge you a premium if you at least load the circuit half its rating.