Single Phase and Three Phase Power -amp Question

[investmentsorg]

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









 

[1714181319]

1714181319

[1714181319]

1714181319

[T-Gee05]

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.

[NotFuzzyWarm]

<snip>
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.

[fanatic26]

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.

[QuintLeo]

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]

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]

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....

[NotFuzzyWarm]

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]

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....

[Philopolymath]

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

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]

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

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.

[philipma1957]

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

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.

[Philopolymath]

retracted

[fanatic26]

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...

Yes it is 3 phase all the way down into the PDU. Its split internally in each PDU xy xz yz. Each leg has its own 20 amp breaker on the PDU.

[QuintLeo]

Death trap..BULLSHIT....It's perfectly safe...SAFER THAN CODE!
Most electrical fires are from FAULTY PLUGS AND RECEPTACLES..
NEC is just another alphabet bloated incompetent corrupt bureaucracy that does not give shit about safety..
They are about maintaining a monopoly and discouraging self education and independence.
Most code was written in the early 1900's when wires were bare or had cloth coverings..
Code is ONLY to absolve big business from liability and while using cheapest materials possible and ensuring profits for G.E.

I used Hospital grade heavy gauge cables rated for 300V 20amp. ..for power cables..
My load is 60%..
I'm a Physicists...experienced retired EEng and know exactly what I'm doing and WHY it is fine.
Philip no offense you are an inspiration & legend in mining but....
Pardon my french...Stick your corrupt Government dumbing down fear porn propaganda up your ass..

 Splices tend to develop intermittant connections due to corruption over time.
 They are NOT "safer than code".
 I've spent way too much time REPLACING splce connections that FAILED AND CAUSED ISSUES to listen to your ignorance.

 Most of the current CODE dates from the 1960s and 1970s with substantial upgrades in every decade since then, not the "1900s".
 If you were an ELECTRICIAN you would understand that - and WHY the code is revised and updated with new and changed information every few years.

 BTW - GE doesn't sell all that much electrical distribution equipment, Schneider sells a LOT more especially since their buyout of Square D.
 GE is a lot bigger in "big unit" power GENERATION equipment like turbines (gas AND water) than in electrical distribution gear.

 The Government doesn't write the NEC, nor was The Government responsible for it's creation.
 In fact, most regulation on building and wiring is done at State or Local level (MOSTLY LOCAL by cities and counties), and they realized fairly quickly that it was easier cheaper AND PROMOTED BETTER SAFETY to adopt the NEC than it was to try to maintain their own ccodes individually.

 Expert at physics does NOT make you an expert at SAFE power distribution.


 Many or most electrical fires are caused by BAD CONNECTIONS, sometimes caused by splices that have corroded over the years, sometimes caused by wires getting frayed by wear (like when some utility companies don't "trim back" trees around their power lines on a frequent enough basis, or when someone lets their cat chew on power cords).
 Many more are caused by OVERLOADS - which is not the fault of the receptacle or the plug, nor is it the fault of the plug when the wiring at the plug gets frayed by misuse or abuse.

[NotFuzzyWarm]

Ja. The NEC is organized, maintained, and published by the National Fire Protection Association which is a private organization -- not part of the government. I suppose you have a problem with UL, CE and TÜV as well?

Yes the NFPA is a consortium of many electrical product along with other hazardous (flammable/explosive handling products) manufacturers and even building materials makers along with the major global insurance companies.

Yes they (manufacturers) have a vested interest in making sure their products are used correctly and on the insurance end insurers want to have some surety that electrical devices and other materials/products are safe to use.

Yes the NEC was developed in part to cover asses and does it by providing a legally recognized framework of recommended minimum requirements AND Best Practices. Follow the guidelines and power systems should not go 'poof' as a result of poor design choices and/or inadequately rated components.

Yes, follow Code to the letter and electrical power system designers/installers are usually off the hook when things happen that are outside of the normal. This is bad why?

As for

They are about maintaining a monopoly and discouraging self education and independence

any part of the NEC you care to look at is freely available for anyone who wants to read it. No joining required. Ja to get the entire NEC ya have to pay for it but so what? Sure smells like easy self-learning of how to do it right and independence to me...

[VRobb]

NotFuzzy, Quint, casting pearls amongst swine again!
Don't argue with idiots:
1st, they bring you down to their level
2nd, they beat you with experience!  

[NotFuzzyWarm]

NotFuzzy, Quint, casting pearls amongst swine again!
Don't argue with idiots:
1st, they bring you down to their level
2nd, they beat you with experience!  

For me at least, not arguing. Just providing an *ahem* properly informed counterpoint to stuff like that so when newbs come across it they get both sides. Most should be smart enough to decide on their own who to believe.

Speaking of which, since it was brought up, link for the NEC page of the NFPA site...

Do note the link for FREE ACCESS to the standards. For the record, standards are updated/revised every 3-5 years with the revisions process which INCLUDES PUBLIC INPUT for various bits typically starting 2x per-year.

[VRobb]

I get that, in fact I made mention of exactly that before I edited my post down for more snark...! But you are correct, if someone is actually doing searches, and lots of reading before spouting off and looking foolish as so many noobs do here, then they deserve to read the corrected version when presented with a possible time bomb due to electrical dufusness.  Trust me, I know, was living with friends of the family back in high school days and had all of my possessions, including a 45 minute tape my mom had me make at 6 years old rambling on about all sorts of stuff - lost in a fire due to electrical amateur hour bullshit.
So that's why I tend to dismiss the idiots, though your approach might prevent someone else from going through what I did...
 

[NotFuzzyWarm]

Exactly.
The only thing I will say in Philopolymath's defense is that ja, knowing the 'why's of things' allows for making an engineering decision about how they are going to do things. That includes what the probable and speaking long-term, possible, outcomes of those design choices will/can be.. In his case, he should know why standards exist and that as an Engineer - which brings possible legal liability - why he cannot in a public forum just willy-nilly blow them off.

If he is happy taking the risks of not following the most basic well established guidelines for his personal setups and knows he shoucld monitor things, fine. However as an Engineer the concept of Professional Responsibility dictates emphasizing to the general public that ja it *works* but....