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In Canada, have an industrial 600 volt x 400 amp electrical service, 20% of which has to stay reserved for other purposes.

How many Antminer S9s (or, I suppose, the new DragonMint...) could this support? Best way to break it down?

Thanks!

People.... THINK about what you are getting into....
If you are asking this sort of question you really need to perhaps pursue other interests...

You are asking how many miners can I power? Fine. Start with:
How many watts of power does each miner need?
A safe answer typically is around 1,400 watts

You say you have 600v 400amp service. Great.
Problem is you have no idea what a 'Watt' is so connecting the dots is http://www.sherv.net/cm/emoticons/school/math-problem-smiley-emoticon.gif (http://www.sherv.net/)

A simple Google search will tell you:  Watts = Volts x Amps
In your case you can supply 240,000 watts or 240kw minus your 20% reserved.
You do the math for how many miners that works out to.

And of course miner PSU's require between 208-240VAC. Need heap-big step-down transformer to go from 600v down to around 220V.

Having fun yet?

No need for snark. I get that watts = volts x amps, my question is more about how to go down from 600v - maybe there are some particularly efficient ways of doing so, especially since I've got to keep 20% for other purposes. It could be that maybe I should try to keep that entirely separate, in case of fluctuations. It could be that it would affect the optimal choice of miner, even, if some fluctuate more than others. Makes sense to ask this group, because presumably some people here know that stuff.

okay  so  600 x 400 = 240,000   while you think  20%  goes elsewhere  I will use 25%  trust me on this

so 240,000 x .75 = 180,000  'free' to mine

derate by 20%  =  180,000 x .80 = 144,000

since an s-9  miner uses about  1440

144,000/1440 = 100 s-9's  

now  here is the funny part  the guy you called snarky  has really good links  for big step down  transformers

I don't know off hand  where to find them.

Since  you are going to be running  a large  operation  I could research it for a fee .

send me a pm.

I know of one company that makes  a 600 volt to  208/120 volt up to 15 kwatts  you could buy  a few  to see it you like them.

they lose about 3%  so  a 15kwatt is about 14500 watts enough for 8 s-9's  once you derate  20%  for safety sake  about 1100 usd





found a second company for you  has a big model  will do the whole load with overhead for 10k  can do 225kwatts

600 volts in  208/120 volts out


shipping is costly as it weighs 1 ton  (well 1925 lbs)

personally  I would order the smaller ones  and have multiple circuits.  if one breaks it is 1100 plus ship to replace  and your others are still working.

After you step it down you will have roughly 96KW left at 240volt. If your reserved power needs to be taken out of that you will have only around 76KW

You should be safe to buy anywhere from 65 to 51 Miners if they pull 1.475KW

Ah. No.... Power in = Power out - transformer losses. As voltage goes down the current you can pull from the lower voltage side proportionately goes up. eg. drop from 600v 400A in to 300v out you now have 800A available.

For decades typical multi-kVA distribution transformers are over 97% efficient. Ongoing government Energy regulations are heading towards mandating >98% eff for anything over 100W and under 1MW.

Back to the OP, thought about how to get rid of the heat 200kw of miners will produce? Hint: Miners are perfect heaters. All power in = the BTU equivalent to that wattage of heat out.

My friend has a shop in the Brooklyn navy yard.

They use big transformers dropping 480 to 208/120

They are as big as a refrigerator .

This is why I told op to get a 15k-watt

They cost 1100 plus shipping and will do 8 s-9s.

At op if you want links contact me.  But I would want a small finders fee.

Ja, smaller POL transformers is a nice solution for another reason aside from redundancy/ease of expansion: service line voltage to the usually distant Point Of Load means that wiring is thinner gauge (cheaper) than what ya need to push 208 that distance. Only heavy gauge wire is between the transformer secondary and a small sub panel w/breakers to feed nearby miner racks.

All things that paid professionals can/will tell you -- and be legally liable for being sure to get it right. Hire some at least for consultation. At your power levels you are talking licensed commercial/industrial electrical and HVAC firms.

Is this 3 phase or single phase?  Huge difference!

  600 volt is 3 phase the transformers I have links for are Wye 600 to 208/120.  I have more then basic knowledge but I am not an expert in this field.

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/ (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.

http://www.oempanels.com/240v-single-phase-and-240v-3-phase

Looking at your calculation.. you just arrived at 329V.. the PSU of the miners are rated 220V.. so you still have to step it down

Philip's calculation is correct. You have to step it down from 600V to 208/120V 3phase then distribute it to single phase circuits in able to power up that psu. That transformer is huge and heavy. We have dry type transformer here at work 480V-230V with a 400A main breaker with a size of 800mmW x 800mmL x 1000mmH housing.

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.

You can always just use 3 phase PDUs and not worry about that last step.

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