Here's a very good explanation of amps on a 3 phase system from a data center perspective:



http://www.raritan.com/blog/detail/how-to-calculate-current-on-a-3-phase-208v-rack-pdu-power-strip

Look into the numbers.  Where I am a $30,000 investment in solar will save me about $1200 a year.  How in the fuck is that free?

Use a dual 6-20p outlet:

https://www.amazon.com/Leviton-5842-I-Receptacle-Commercial-Grounding/dp/B000U3BVMI

Attached to two 6-20p to c13 y splitter cables like this:

https://www.rackmountpdu.com/category/189-6-20p-to-c13-splitter-power-cords.aspx

That will do 4 units for less than the cost of a PDU alone.

Consider Y cables.  3 outlets 3 cables feeding 5 or 6 units.

What voltage are we talking at these amps?  1 phase or 3 phase?

They likely will want to provide you with 3 phase power.   Tell them you should be able to balance the load across the 3 phases and have a high power factor (likely .95-.99). Ask about cheaper rates if you buy your own transformer.

I suggest doing some reading on the above.  If you don't have a site yet do some research on what voltages are available where. 

329KW not 329volts.  His calculations work for single phase power not three phase.

If a single 3 phase 600v primary transformer is used he would need a 330 kva transformer, but would only get 208v on the secondaries phase to phase. 120v phase to neutral.

If 3 x single phase 600v primary transformers are used then 110 kva each will get the job done and he will have 240v pole to pole. 120v pole to neutral.

I am not aware of a 3 phase transformer that will deliver 240v phase to phase because the're designed for 120v and the phases are out of phase (not using the neutral on the primary side) that's why you only get 208v (120 x 1.732)

Also keep in mind the 240v is across poles which is what we want (240v 3 wire not 240v 2 wire)

Please someone school me if im wrong on this.

I am not an engineer or electrician.

Here's how I think the math works, and I will explain each step:

600 volts RMS  < ----This is ACROSS the phases, not phase to neutral

347 volts RMS <--- Phase to neutral

400 amps is 3-phase < ---- This is the most important part.  You have 3 phase power but are running 1 phase units.

Using https://canadatransformers.com/transformer-phase/ to calculate KW/KVA using all 3 phases:

600v x 400 amps = 415.69 KVA

(600 x 400 x 1.732)

Calculate using a single phase:

347v x 400 amps = 138.8 KVA

Yup checks out, it's 1/3 of the 3 phase.  So we have a total system KVA of 415.69.  To translate to KW we need to multiply by the power factor:

415.69 KVA x 0.99 = 411.5 KW

So we have a total system KW available of 411.5, multiply by 0.8 (80%) to get available power:

411.5 * 0.8 = 329.23 KW available

Divide by 1.475 KW:

329.23 / 1.475 = 223 units

That's a lot!

Where are you located?  I'm in Winnipeg.  What is the size of the transformer in kva?

Edit: I did not include transformer losses since we need to knock down that 600v further.

Is this 3 phase or single phase?  Huge difference!

That's more than I expect which is good for what I want to do. It also means they're not moving 200 cfm.

I know the fan runs about 200 cfm on these units but does anyone know the temperature rise? My math says it should be about 25 degrees.

Is 80f safe for an inlet temp?

https://www.cryptocompare.com/mining/calculator/btc?HashingPower=14&HashingUnit=TH%2Fs&PowerConsumption=1293&CostPerkWh=0

Why is this so hard? I don't mean to be an ass but come on...

Most likely an issue with the power side of the board or a bad solder joint. I have no experience with these boards just electronics in general.

I filled out an order for 2 s9s and 2 psus and it came to about $210 USD in shipping costs. Anyone have an idea how much more I would pay?

Just checked my voltage and I have 244v. Lucky me!

I'm going to guess if you have higher voltage in the house you may be able to get away with running 4.  Short runs of wire, low voltage drops etc.  will really help as well as efficient PSUs.  Also the hotter ambient is the more amps will be drawn obviously.

GST + PST + duty + clearance charges

Anyone know how much the latter two are?  There are ways to clear things yourself.

Hey thanks for the detailed response I really appreciate it. Sounds like a house with close to 240 volts is best for the bitmain PSUs so maybe it's best to have that influence my decision. Also I've heard that the other units have voltage protection etc.

Maybe becoming an expert on fixing the power supplies is a good idea if you want to order them instead of the aftermarket units.

For 220v is it just best to go with the bitmain PSU?

What is a good ambient temp to aim for? Is there efficiency gains below a certain point?

Sorry for the noob questions.