Transformer size required

[ronball]

I have a customer wanting to know how much power for their Bitcoin mining business.
they had 430 rigs that each use 3.5kw/ph at 240/415 volts.

I think I came up with transfomer being about 6000 amps.
Does this sound about right?

 

[don_resqcapt19]

3.5 kW per phase does not sound correct.

 

[ronball]

I stand corrected they use 3.5 kw per hour running, not per phase..

 

[petersonra]

3.5 kW per phase does not sound correct.

each computer is hooked to 240 V. 3.5 kw per computer does not sound crazy to me for this type of computer.

430 * 3.5 kw = 1505 kw
I get about 2100 Amps.

 

[ronball]

the 3.5kw/ph was meant to be per hour, not phase.

 

[petersonra]

I stand corrected they use 3.5 kw per hour running, not per phase..

kW is a rate, so kw/hr is not an appropriate unit.

If they are using 3.5 kw-hr per hour, that is the same thing as 3.5 kw per computer.

 

[electrofelon]

Perhaps it would be prudent to meter one of the units......

 

[tortuga]

Assuming you can balance all the 240V L-N loads
I would take the nameplate VA of the units total them up add a 25% continuous factor then divide by 720.51V (416 * 1.732 V)

Side note I call our new standard voltage '416/240' should I be calling it 415/240?

 

[LarryFine]

Side note I call our new standard voltage '416/240' should I be calling it 415/240?

The former; it's twice 208/120.

 

[tortuga]

Thats probably why I call it 416/240.

 

[tortuga]

If they really are 3500VA per unit I come up with 2089 Amps:

Qty​	VA​	VA total​	Amps​
430​	3500​	1505000​	2089​

Assuming you can balance the load on all three phases.
I wonder what the lead time on a 2000 kVA padmount 416/240 transformer is?
EDIT: I did not add the continuous factor