Topic: Power supply question 240volt 3phase power vs 1 phase (Read 4924 times)

 Please  just make sure 10 gauge wires  30 amp 2 pole switch.

That adapter setup is a bit shaky but the unplugged receptacle  next to the sub is 10 gauge 1 single 30 amp plug to the 30 amp 2 pole circuit in the circuit breaker.  It is code and derates to 24 amps 24/7/365 or about 5760 watts.  finsky has those big ass 2880 watt loud as fuck psu's for sale you can do 2 of them on 1   240 volt  pdu.

philipma very nicely done on the install.  Looks great.

Thanks for help aswell on 240, hopefully I will finnaly get one in next week or two.

I have done my home with 2 outlets.  but it is your standard  2x 120 lines and a ground.

This plug was a dedicated subwoofer outlet but 120 volt.  10 gauge romex easy to convert.  just add the 240 socket in the wall and a 2 pole circuit breaker in the circuit breaker box.


This was on of 3 subs power by that older 120 volt socket.




next is the 240 that is in use with a pdu. I had a
120 volt 20 amp socket only 2 feet from the breaker box. I pulled the 1 pole  20 amp circuit breaker and added a 20 amp 2 pole breaker

note the black nema 15r to l6 30r adapter.  It means I can change this socket back to 120 really fast.




pdu  with 1 evga 1600 p2 hooked up


http://imagizer.imageshack.us/v2/1024x768q90/905/mriEMM.jpg




note how the pdu has plug holder.  I purchased a yellow plug cord to show this to you all as clearly as possible.

  He can spare 30 amps of it which = 3 pdu's at 10 amps each as a max.
  my goal is 6 miners using 3 psu's at the 1000 watt level  which should be only 4 or 5 amps a pdu.

 I have 2 x 1200watt plats
 I have 1 x 1600 watt plat
 I have 1 x   750 watt plat
 I have 1 x   650 watt plat
 I have 2 x  1300 watt gold
 I have 1 x    650 watt gold

 I would be able to go 2x it if things are working out well. So it is not a question of have to get pdus or psus

 Just need to be sure what each of the 3 balanced plugs will supply me 208 volts or 240 volts.

You will want the meter to see what is going on at the level of each phase.  If you are going to push what is available at the location, you will want to see what each of the phases are pulling at the service entrance.  You know, if you have a 100 amp service, make sure you keep it at 80 amps for each phase, that kind of stuff.  

I am going back to his place in May I will report back on results.

I believe using 1 of the 3 phases is fine (along with a neutral and a ground), but using 2 of the 3 phases may cause bad things to happen. In a normal 2 phase configuration, the 2 hots are orientated 180 degrees from each other. But if you use 2 phases from a 3 phase line, the orientation is different, being in a 120 degree / 240 degree rotation. This causes the net difference in voltage between the 2 phases to be much lower, and I have concerns that the circuitry inside the power supply only expects a certain waveform of net voltage.

Ninja edit: After some shenanigans with wolfram, turns out the waveform of 2 phase power coming from 3 phase is exactly the same as a normal 2 phase coming from 2 phase with just different net voltages. Assuming the peak voltage of 240v 3 phase is 240v between all 3 phases, each phase is 120v. Putting 2 of the phases as hots in an ATX power supply, you have 208v @ 60hz. So what you are proposing is perfectly fine. Just make sure your PSU input looks something like 100v-264v. If its 115/230v, bad things might happen.

I'm electrically stupid. But not that stupid.

  the pdu's have built in amp meters so I will attempt to have each one at 4 

Also grab one of those amp meters you can put around each of the phases (to see how many amps are being used).  They will allow you to answer weird questions like say you are using 10 amps on each phase, and you add another 5 amp psu (using say 1200 watts) to 2 of the phases or 1 phase and neutral.  Does that increase each leg by 5 amps, 2.89 amps, or 2.5 amps?  5 minutes of testing and it will all make sense.

I have 3 pdu's and many psu's

should be able to do this in very early may.

Generally, a 240V 3 phase system will be configured as a delta, while 120V/208V systems are configured as a wye. Either way, you just want to balance the load across the phases. Run the PDUs in multiples of 3, and try to keep the draw on each even.

Thanks for the info.  I will read up on it so that when I drive back to my friends shop I will have an idea of what I am doing.

Forgot to add there are two main forms of 3 phase called 'delta' or 'wye'.

Here is a place where they get geeky about the sematics: https://www.physicsforums.com/threads/delta-vs-wye-pros-and-cons.682676/

TL;dr: wye will have 4 wires instead of 3, the fourth being a neutral, so if you tie any hot to a neutral you get 120v, and there is no 'wild leg' (all hots carry 208v).

All the wye stuff I have seen is 120/208/277/480v, take a look at this chart to see whats out there: http://www.ccontrolsys.com/w/Electrical_Service_Types_and_Voltages

I can not duplicate results using dicus fish pool  that I got using ck's solo pool.

so I suspect I have a pool skew no not a pool cue.  I will test more.

As for servers the intel 1000/1200 server is quiet up to 650 watts when my amp meter read 2.7 for 240 volts = 648 watts it was quiet .

Of course go past 750 watts it is loud and go to 1000 watts it screams and at 1200 watts it wails.

All the spots I can mine need quiet or medium loud miners.

Yes, they are loud. Not for the faint of heart. Sloopy claims he sleeps with them, but I'm not convinced he actually sleeps. LOL!  Yes, J4bber has already been successful with a fan design that keeps noise lower than an S3 running.  I just received a couple PWM fans this weekend that I'm going to rig up and see both how much lower I can get the noise while still supporting full 2880W. I'll let J4bber comment further on his design, but I am excited for allowing more people to take advantage of them for still quite reasonably.  If only they could work on 120V, we'd be in great shape.

Sloopy, it's all good.  Again, I've always known 240V is superior for PSU's in almost every way, but I always thought the DC output voltage was stable regardless of input.  If it does have a positive effect on the hardware, that's an even bigger reason for people to make the switch.

Phillip, keep us updated.

I will now uplug the intel and do a 120 volt input.

dc reads 12.16 which is better

power reads 369 on one kwatt meter. Since I have 2 kwatt meters and 1 other watt meter I know I will get 369 369 and about 380.  which will be most likley just a tad higher then the 240 watt pdu amp gauge gave.

I am 5 minutes into testing with 120 volts

So you show the 240 volt numbers with the Intel server psu, please show us the 120 volt numbers.

okay  here is my avalon 4.1 running on the intel  at 240 volts dc volts out = 12.15 :

error rate is under 0.100




the intel prefers 240 volts as it rates at 1200 watts at 240 volts and at 1000 watts at 120 volts



pdu = 1.5 /1.6 amps 240 volts so 360 to 384 watts


more shots at links below
http://imagizer.imageshack.us/v2/1024x768q90/673/G0Ssrh.jpg
http://imagizer.imageshack.us/v2/1024x768q90/673/bFzOFA.jpg
http://imagizer.imageshack.us/v2/1024x768q90/538/PmAssZ.jpg

My apologies and actually I should have looked who posted and I would have realized your intent. I replied after first waking up. Probably not a good choice

And yes Phil I will agree with Fin on the 2880 now that I hear you have access to a shop and it would not be in your home. I know not everyone can have the howlers in their home but I sleep with a couple of them.

alh there are fan mods in the works. I haven't looked lately, but Jabber and Fin were working on some things.

I plan to order again soon Fin, I will PM.

Isn't it pretty loud over there on the dark side?   

I haven't seen a server power supply that even pretends to be quiet. The ATX EVGA supplies seem pretty quiet to me. That's only based on a sample size of one. My bet is that by now, all the server PSU designers are hearing impaired from the noise.

The IBM 2880 looks enticing to me too (240 volt).
 
One reason I have not moved to the single IBM 2880 with the breakout board is that it introduces a 'single point of failure' for all the miners running on that power supply. 
If it goes, "poof" one night all those miners quit working (100% dead).
I'll probably just install a pair of heavy duty 20 amp (120 volt) circuits in the garage this summer and those miners will heat the garage in winter.

Don't waste your money on the EVGA's Phil, come to the dark side. 2880 Virgin Watts await you in the kingdom of 240 volts... 


Sloopy,

I'm not doubting his claim, I was asking if he had come up with any reasoning, since AC input voltage theoretically should not greatly influence DC output voltage, which is why I asked if he measured the output to see if there was a difference.

Do not be so fast to assume Phillip's gear did not have a gain in performance.
If he says it did be more optimistic.
I have seen this first hand and there are examples posted not only on this forum but all over the internet.
It is easily explainable by confirming the unit's were not receiving "enough" voltage and amperage prior to the move
Or
The units have specific design qualities which utilize the new scenario.

Phillip has shown his knowledge of the miner side. Just because he asks a few questions on the 3 phase does not mean he presents data without factual basis.

For a real world example imagine you under power a lot of S3s with a power supply which regulates the output evenly (I say evenly, but it regulates somewhat without bursting into flames across all S3s), even when "overdrawn", IE the 2880. You can load that baby up with significantly more S3's than you should and she happily hums along lowering the output to each. Most of the S3's may run at 400 a couple at 440, one or two at 390, but they run. Performance is impacted.
Remove enough S3's and alacazam, you get 450 and 500 out of your poor little beasts.


Edit for safety:
Do not overload any power supply, it simply isn't safe and most go pop. (Same for any power source, calculate your supply VS your draw, add 20% safety factor)
Power cycle after any significant change to any electronic device
Keep your hands away from anything with live voltage, IE do not connect live wires to miners.

Your Mileage Will Vary, depending on several things.

that is the plan

Hey Phil,

Long story short, all of your PSUs will not be able to use 3 phase, so you will either give them 2 of the phases and a ground, or 1 phase + 1 neutral + 1 ground.  Always go with 2 phases and a ground as you will need less outlets, wire, etc when using the higher voltage that is from 2 of the phases.  

It sounds like you have a high leg delta system, so I believe one of the legs will be 240, off the top of my head I think the other 2 legs will be 208.  I have never used a delta system, they are older and were for supplying extra volts to start motors.  Your a smart guy, grab a multimeter and you will figure it out quickly (just be careful with live wires).  

I am in Europe. At home I have 3x25A 230V splitted to several parts:

one phase
- 3x 16A - for wall sockets (each max. 3680W)
- 2x 10A - for lights
3 phases
- one separate for 5,5kW electric stove

Usually I have simultaneously aprox. 9kW (miners in wall sockets) and also no problem when I work with 5,5kW electric stove.

short term I will be doing 240 volt in house. long term I have to see exactly how his shop is wired.

I would love to have a 30 amp circuit .

His shop is 1 large room around 1200 square feet . It has 16 foot ceilings. 7 cent power. Would be nice to run a lot of gear .

5 evga 1300's could do a lot. Even 4 would be nice.

The gain in PSU efficiency is understandable, but do you really think the higher hashrate was due to the AC input voltage to the Power supply?  Have you checked the DC voltage?

I honestly know nothing about 3-phase, but I would be cautious as to how you split the legs up to convert it to single phase...
Here is an article about using transformers to convert between three phase and single phase: http://carroll-meynell.com/technical-3phase

gear seems to do higher hash rates and less power draw.

Not a lot maybe 2 percent and 2 percent  but that is around a 4 percent improvement.

 My cost to do it was under 150 usd for 2 circuits and  that is  counting 3 good pdus on ebay.

http://www.ebay.com/itm/121380956007?

http://www.ebay.com/itm/121298867226? >>>>>>>>>> he still has some of these.

From what I gathered from a electrician is 3 phase is used in industrial areas and devices have to be split evenly across all three phases.  It can run more efficiently if used properly but for our uses and for the future single phase is best for you.

The PSU will not see a difference as far as the number of phases go, cause it will only see two phases regardless of single or three phase grid feeds.  You are probably better to go with three phase 240V or single phase 240V since its higher voltage.  Depending on Wye, Delta or high leg your voltage from two of the legs of a three phase circuit can be 208V or 240V.

3 phase is generally used for generators. You can use it to mine by looking at the similar diagram.

10 gauge copper is good for 30 amps, 10 gauge aluminum is 25 amps.

Yes, 10 AWG is what is needed for 30A, you're fine at 35'. Your PDU is likely also 30A, but derated (80%) to 24A. I've run my PDUs at 30A without issue, but try to keep them at a max of 27A.

How are you liking the switch to 240v from 120v? 

I got 2 phase in house and finally did 2 circuits into 240volts.

My friend  with cheaper power has ' 240 volts 3 phase'  and runs a lot of heavy machinery in his shop..   those quotes are what he told me.

When I go back to his  place I will bring a meter and figure out what he really has.

In my home the one I wired with 30amp 2 pole breaker to a 30 amp plug is 10 gauge a 35 foot run.  What can 10 gauge handle safely?

  The pdu is fused for 24amps.

   I know 12gauge is okay for a 20amp 2 pole 240 volt.

Is 10 gauge okay for a 30 amp 2 pole 240 volt.  1 single 240 l6-30r plug to a 24amp pdu.  TIA

^that sounds correct. Thats a 30A receptacle, meaning you can load 5.5-6kW on it (208 and 240V respectively, achieving 80% load). It would connect to your breaker panel using a 2-pole breaker (plus GND)

Now if you have a 30A 3-phase, thats a bit different and is quite unlikely to be seen in a residential building. (90% of homes are 2-phase, each at 120V, to allow 240V when running both phases). A 3-phase breaker will only work properly on a 3-phase panel - on a 2-phase panel you would have 2 rows of 240V sockets, and one row of 0V (since its 2 hot lines of the same busbar)

3-phase is generally for industrial, where power is stepped down from a 600V service, giving 3 hot lines, each at 120V or with a difference of 208V between any two lines. You should balance the load across the three phases

If your going from hot <-> hot it will be 208/240v. But thats not a bad thing, unless you absoletely have to have 120/110 skip it. I'll bet all your bronze rated ATX PSUS's or better not older than 2 years will automatically switch and run better with the higher voltage.

Here is a picture of a box my brother in law made up for me, we will hang one of these above each 400A 208V 3-phase panel to have a visual proof of what is being used and how balanced. FYI these meters were $5.08 each off alibaba  (they also require a CT)

I GOT A HOLD  of 3 very nice pdu's

Each is 24 amps 3 wire hot-hot-ground twist lock.

 Price was under 80 for the 3 combined .

so if I make the 3 receptacles correctly I should have 3 balanced pdu's my guess is all the hots are going to be 120.

I am going to have an excess of power for a change.

I will only be using 208V exclusively for miners, so none of the hots carry 120V. There are 5-wire 3 phase pdu setups that also bring in the neutral to allow you to go from phase to neutral to achieve that. I haven't been able to find any of those guys in the high wattage dept at the scrapyards.

okay I think I get it.

Next question  what are each of you hot wires carrying 120 volts?   1.732 X 120 = 208

You could engineer/wire it in a way that it pulls from two of the phases straight from the panel so you could use such an outlet on a three phase panel. That may be what he is doing and probably the norm. I'm setting up my datacenter with 3 phase PDU's so I bring all 3 phases out from the panels to closer to where it's used. More efficient that way, less metal to conduct more power.

That is a NEMA L6-30. for Single phase 240v applications, the three conductors you see there are for hot-hot-ground. Three phase will have either 4 or 5 conductors. They would be hot-hot-hot-ground, or alternatively hot-hot-hot-neutral-ground.

https://en.wikipedia.org/wiki/NEMA_connector#NEMA_6

okay the guy's shop has a ton of 3 hole twist-lock receptacles . I think I need to measure the power on them as

I thought they looked like this





these would have 2 hots and a ground  each hot would be a 120 if you went hot to ground.  but if you go hot to hot you get 240.

if  measure his power and get that result  it would be more like 1 phase.

your description has me a bit confused maybe his  shop wiring is doing what you say if I understand you correctly  3 hots feed into his shop.

and each 3 prong twist plug he has is using 2 of the 3 hots.

So if I want to load balance. with the 3 hots named 1 2 3

    I make 3  receptacles

  1+2+g is the first plug
  2+3+g is the second plug
  1+3+g is the third plug

each one does a evga 1300g2 running at 1000 watts   and we are load balanced

This confused me too at first before I did some research into three phase. I like to think of it like this (and please pardon my newb explanations):

Single phase AC has two hots, with each hot maximum potential 180degrees out of phase each cycle(hertz)

Three phase AC has three hots, with each hot maximum potential 120 degrees out of phase each cycle. Think of this like a triangle instead of a teeter totter.

You can use Three phase as single phase, just use two hots from the three phase. Of course this will only put a load on one 'side' of the three-phase triangle. The additional trick needed for three phase is 'balancing' the load of all three 'sides/phases' of that triangle so power is pulled evenly. Ammeters on each phase can provide a visual representation of what is going on, or you can just depend on careful calculation and wiring. Transformer life and many other thinks can quickly deteriorate if you are running unbalanced in any significant way.

So with just one more hot with 3 phase, you essentially can pull single phase from three points.

An example with a 3 phase pdu I have: 3 phase power cord, 60A, @ 208V. It has 6 C-19 outlets on it. Outlets 1-2 are connected to Phases A-B. Outlets 3-4 are connected to phases B-C. Outlets 5-6 are connected to phases C-A. It will not self balance, but requires that similar loads are put on these groups of outlets.

Here is a number you should memorize (it is not exact but gets you close enough)

1.732

To calculate wattage available from 3 phase : AMPS X 1.732 X VOLTAGE

Hope some of this helps, three phase is cool beans!

okay I have a glut of power supplies

 Evga  1300 g2
 Evga  1300 g2
 Evga  1600 p2

Seasonic 1200 plat
Seasonic   750 plat
Seasonic   650 gold
Seasonic   650 gold

Antec       600 plat

Intel server   1000 watt 120vol  1200 watt 240 volt plat

I finally wired one socket to 240 volts in house and I have a good improvement.


but all of the above is back ground info.  I have a friend that can give me 30 amps of 240 volt power at 7 cents a kwatt  but it is 3 phase so pardon some lack of knowledge on my part can an atx psu run on 3 phase power source.  I know the power wave on 3 phase is staggered but at that point I run out of knowledge. 

Short of plugging in an atx psu to test for shorting overloading or shaky 12 volt pc output, what is the story on 3phase vs 1 phase for atx psu's.

I think all of my psu's have active  PFC if that is helpful.