Single Phase and Three Phase Power -amp Question - page 2.

philipma1957

legendary

Activity: 4242

Merit: 8515

'The right to privacy matters'

Quote from: Philopolymath on October 08, 2017, 10:29:37 AM

Why does everyone over think and try to over-engineer..
It is SOOOOOOO SIMPLE cheap and effective to just do this...

Quote from: Philopolymath on October 08, 2017, 08:20:05 AM

And All 8x S9's Running just fine...Mission accomplished

NOTICE NO PDU NO PLUGS..3x PSU's are connected straight to 220V 30amp line using bare wire and marrets & electric tape.

You built a death trap.

But it is cheaper and it does work.

QuintLeo

legendary

Activity: 1498

Merit: 1030

Quote from: Philopolymath on October 08, 2017, 10:29:37 AM

Why does everyone over think and try to over-engineer..
It is SOOOOOOO SIMPLE cheap and effective to just do this...

Quote from: Philopolymath on October 08, 2017, 08:20:05 AM

And All 8x S9's Running just fine...Mission accomplished

NOTICE NO PDU NO PLUGS..3x PSU's are connected straight to 220V 30amp line using bare wire and marrets & electric tape.

Serious code violation, and DANGEROUS.

Not a real good idea even if you KNOW what you are doing.

There is a REASON the NEC is very much ANTI-SPLICE and has been so for a while - as I recall even the old-style "wire nut splice" method is depreciated for new construction in recent versions of the Code, and it's never been considered a "best practice".

Keep in mind that the NEC came about to prevent FIRES, and who is behind it.

Philopolymath

sr. member

Activity: 558

Merit: 295

Walter Russell's Cosmogony is RIGHT!

Why does everyone over think and try to over-engineer..
It is SOOOOOOO SIMPLE cheap and effective to just do this...

Quote from: Philopolymath on October 08, 2017, 08:20:05 AM

And All 8x S9's Running just fine...Mission accomplished

NOTICE NO PDU NO PLUGS..3x PSU's are connected straight to 220V 30amp line using bare wire and marrets & electric tape.

QuintLeo

legendary

Activity: 1498

Merit: 1030

Quote from: NotFuzzyWarm on October 06, 2017, 06:51:01 PM

Quote

I use 3 phase all the way to the PDU xy xz yz

As in the PDU's have 3-phase line-in and split it off to 3 banks of single phase pairs inside of the PDU's? That would be pretty damn handy...

I think I've seen at least one high-end PDU do that, but I'd be more inclined to suspect he splits the 3-phase out to single-phase and feeds the PDUs from the single-phase.

Liebart is comming to mind....

NotFuzzyWarm

legendary

Activity: 3752

Merit: 2667

Evil beware: We have waffles!

Quote

I use 3 phase all the way to the PDU xy xz yz

As in the PDU's have 3-phase line-in and split it off to 3 banks of single phase pairs inside of the PDU's? That would be pretty damn handy...

QuintLeo

legendary

Activity: 1498

Merit: 1030

Using 3 phase to direct-power single-phase gear often puts too low a voltage on that gear to work properly - though most MODERN power supplies can handle 208 (nominal) input voltage.

Most folks don't want to deal with the hassle and PAIN of phase balance - and most 3-phase electric feeds are to places that use gear that NEEDS 3-phase anyway, like large manufacturing machines.

Large cryptocoin mines and large datacenters are not the norm in most areas....

fanatic26

hero member

Activity: 756

Merit: 560

Quote from: QuintLeo on October 05, 2017, 01:46:12 PM

3 phase distribution that feeds a single-phase (or a North American "split phase") setup generally uses a transformer to convert - which renders the "balance the phases" issue moot.

I use 3 phase all the way to the PDU xy xz yz

Whats the point of having 3 phase power if you just have to use extra hardware to convert it?

QuintLeo

legendary

Activity: 1498

Merit: 1030

3 phase distribution that feeds a single-phase (or a North American "split phase") setup generally uses a transformer to convert - which renders the "balance the phases" issue moot.

fanatic26

hero member

Activity: 756

Merit: 560

Quote from: NotFuzzyWarm on October 05, 2017, 08:30:35 AM

Um, we don't do 3-phase calcs because the PSU's are fed single-phase so only single-phase calculations apply. Ja large locations have incoming 3-phase and some of that will feed 3-phase motors and or A/C but thass it. All else is split off as 1-phase.

This for sure. You dont make any changes to your calculations between the two. At the end of the day you are still feeding single phase power to an individual unit. You will still only be able to put the same amount of miners on a circuit.

Also as T-Gee05 said, it is incredibly important to balance the draw across the phases if you are running 3 phase power.

NotFuzzyWarm

legendary

Activity: 3752

Merit: 2667

Evil beware: We have waffles!

Quote from: investmentsorg on October 04, 2017, 05:32:24 PM

but for 3 phase its less
=(1372/208)/1.73 = 3.81 amp draw

Then simply add 20%
so 120% X 3.81 = about 4.57 amps to be safe

So like 40-41 miners on a 200 AMP panel if its 3 phase power

I have seen people not doing the 3 phase part of the calculation and only doing 34 miners
I am assuming you have more power for fans and stuff.. but just to give a simple overview
Am I missing something ?
Most people do only have single phase power but larger location are 100% 3 phase power.

Um, we don't do 3-phase calcs because the PSU's are fed single-phase so only single-phase calculations apply. Ja large locations have incoming 3-phase and some of that will feed 3-phase motors and or A/C but thass it. All else is split off as 1-phase.

T-Gee05

member

Activity: 67

Merit: 10

This depends on your application to your electricity provider. The maximum allowable demand load for single-phase service applications is 75 kW. Single-phase service applications with demand load requirement of more than 75 kW shall be served at three-phase service instead. Average household only have 100A load in a single phase supply. This is with reference to where Im from. Im not sure about the regulations in your areas.

Having 3 phase electrical system is really cheaper in terms if current (delta configuration system) where the phase current is less than the line current. But be sure to balance your load.

investmentsorg

newbie

Activity: 5

Merit: 0

So I am 90% I have it correct now after talking with my electrician but I have seen some numbers posted that I think are wrong

1 - S9 will draw

1372 watts / 240 = 5.72 Amps on single phase power
but on 3 phase power the math is like this

but for 3 phase its less
=(1372/208)/1.73 = 3.81 amp draw

Then simply add 20%
so 120% X 3.81 = about 4.57 amps to be safe

So like 40-41 miners on a 200 AMP panel if its 3 phase power

I have seen people not doing the 3 phase part of the calculation and only doing 34 miners

I am assuming you have more power for fans and stuff.. but just to give a simple overview

Am I missing something ?

Most people do only have single phase power but larger location are 100% 3 phase power.

Any incite would be really appreciated

Topic: Single Phase and Three Phase Power -amp Question - page 2. (Read 1624 times)