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Topic: 3 BTC bounty for the best assistance! (Read 4863 times)

donator
Activity: 1218
Merit: 1079
Gerald Davis
April 02, 2012, 09:45:19 AM
#41
Basically nothing is designed to work on 208V.

That will be news to every datacenter in the world. Smiley

208V single phase
http://www.apc.com/products/resource/include/techspec_index.cfm?base_sku=AP9571A

208V 3 pahse
http://www.apc.com/products/resource/include/techspec_index.cfm?base_sku=AP7516

ATX PSU have no problems working @ 208V.

The rest of the info was good just not sure what you were trying to say with the quoted sentence.
member
Activity: 65
Merit: 10
March 31, 2012, 07:42:03 PM
#40

-Some discussion on 110v vs 220v power.  I have limited knowledge here, and would love a good paragraph or two on advantages, ease of implementation, pitfalls, etc.

-Phase 3 power discussion.  A lot of the listings I looked at had this as a feature....I do not want to research this, and would rather pay a bounty for someone to sum it up with common English.  

-AC cooling.  For those of you working in enclosed spaces....I realize it is almost impossible to cool a sizable farm on AC alone without venting the waste heat.  With venting, how much AC power would one need to properly cool a 15-20 GH/s installation?  Square footage would be around 800.  

THANKS!!!

Hi, heres the info. You requeted.  I am a senior level mechanical and electrical engineering student .  I can clarify or simplify any part at your request.

#1

Quote
Basically the power that comes into your house in an alternating current.  This is  opposed to a constant (Direct current) current that is found in batteries.  This means the voltage found at your wall outlets goes form +120 to -120V at a rate of 60 times per second.  \

Generally, to transfer power you need both a negative and a positive wire.  But in a very specific situation, due to how power works, it is possible to completly eliminate the negative wires.  To accomplish this, it is necessary that power is generated by three sources that a phase angle of 120* apart.  After that criteria, if the load of each those generator is the same (balanced), the the negative wires can be completely removed. (If the load on these generators is not perfectly balanced, then another benefit is that the thickness of the negative wire can be greatly reduced.)  This allows electircal utility companies to run 3 wires instead of 6 and is a huge cost savings.  All of these three phases are available to your house.

To make what I said brief, the advantages of 3 phase power are mainly geared towards the electrical utility company as cost savings from wire reduction.

#2

Each of the three phases are available to a residential/commercial building.  A schematic is show below.

 

Now what is not pictured in the schematic is the negative wire (since it is not needed).  In our electrical setups we use the earth as a ground (negative wire).

Here are the mathematical results of the power combinations.

Phase 1 - Ground --> 120V (Also called 110V since it dips down as low as 110V, its not perfect)
Phase 1 - Phase 2 -->  240V (Also called 220V since each phases dips down as low as 110V)
Phase 1 - Phase 3 --> 208V

Basically nothing is designed to work on 208V.  It is worthless to your application.  It is a possible combination from the utility power transfer setup.  **One exception.  Some large motors are designed to work on a three phase source.  This makes the motor operate smoother, but since this connection is not readily avialable it is restricted to large commercial machines with specialized connections.

Now here is something interesting for you.

Basically Volts * Amps = Power

Transferring more amps heats up the wire.  This requires a large wire.
Transferring more volts does not affect the wire.

You can think of volts are pressure, and current as flow.  

A larger pressure is nothing.  Think of a compressed air tank.  It just says constantly compressed.
But a flow of air causes friction.  This larger your flow (amp), the more friction shows.  This friction is lost as heat and seen as a loss in efficiency.

This means that the same gauge wire can transfer twice as much power on 220V.  <-- This is what you want.  Its more efficient and has more capacity.

#3

Easiest way to deal with the heat is to vent it to the atmosphere using a fan.  Since you are not living in it so even if its on a 100*F summer day, a 100*F is nothing for computers.  But if you need this environment has to be livable and do not have access to the atmosphere, this means a large air conditioning setup will be needed.  But still a better method would be of transferring heat away (outside).  If you cannot use air (simplet and cheapest).  Then see if you can find an exit using water transfer.  This will allow you the transfer away the heat, which will be stored in the water, before the generared heat has a chance to effect the inside too much greatly reducing the load.  This could mean constantly running water down the drain from a heat exchanger, or better yet.  Running this hot line outside to an evaporator.

If this helped and the bounty is available please send it too.  If you need more help please post or PM me.  I need me some bitlotto money.  Maybe one day, ill win.

13TYbCRVqNcGsnubrU8j1gTDrNUYiuEBhq
rjk
sr. member
Activity: 448
Merit: 250
1ngldh
March 28, 2012, 06:58:53 PM
#39
this is 12/3  run from a subpanel on a 20amp double using regular plugs.  

feeds my seasonics nicely!
http://i1027.photobucket.com/albums/y335/jjiimm_64/10x7970%20rig/IMG_0522jpeg.jpg
Good luck getting the inspector to approve that. Grin

legendary
Activity: 1876
Merit: 1000
March 28, 2012, 05:56:00 PM
#38
Unless you have a well and a septic field.  Or maybe you could take that and run with it.  Bury a bunch of pipe and circulate the water through it.  At least I didn't suggest running 30amps of 14/2.  


I dont think anyone suggested running 14.

this is 12/3  run from a subpanel on a 20amp double using regular plugs.  

feeds my seasonics nicely!


legendary
Activity: 1512
Merit: 1000
March 28, 2012, 05:25:24 PM
#37
What are your water rates?  If you don't care about dumping it down the drain...

Even if water was free,  It cost a shitload to purify water. What a polluter you are. (tap water that is.)

Unless you have a well and a septic field.  Or maybe you could take that and run with it.  Bury a bunch of pipe and circulate the water through it.  At least I didn't suggest running 30amps of 14/2. 

Are you implying that running water through that swamp cooler is contaminating it?  I'm not sure I get what you're saying.  If you're trying to make a point about the added volume at the processing plant, I don't think your concerns might be a little sensationalist/parabolic.

donator
Activity: 1731
Merit: 1008
March 28, 2012, 04:37:59 PM
#36
Planning to cheap out again, my breakers do not have holes to ties them together,

Tell me, is there a part I can buy that ties them together ? ... before I duct tape them Wink
http://www.grainger.com/Grainger/ecatalog/N-1z0dud4
Thanks, 0.5 btc for that. Wink
rjk
sr. member
Activity: 448
Merit: 250
1ngldh
March 28, 2012, 04:31:44 PM
#35
Planning to cheap out again, my breakers do not have holes to ties them together,

Tell me, is there a part I can buy that ties them together ? ... before I duct tape them Wink
http://www.grainger.com/Grainger/ecatalog/N-1z0dud4
donator
Activity: 1731
Merit: 1008
March 28, 2012, 04:30:55 PM
#34
Planning to cheap out again, my breakers do not have holes to ties them together,

Tell me, is there a part I can buy that ties them together ? ... before I duct tape them Wink
rjk
sr. member
Activity: 448
Merit: 250
1ngldh
March 28, 2012, 04:27:53 PM
#33
Yochdog, I haven't heard from you what kind of ambient temps to expect in your location - lowest winter temp, and highest summer temp. Also, whether you would be allowed to cut holes in the side of the building for large fans. Once I have that info, I could advise better on necessary cooling.

For instance, in Florida you want A/C year round, but in Ohio you would be able to scavenge outside air during the winter using a variable damper.
rjk
sr. member
Activity: 448
Merit: 250
1ngldh
March 28, 2012, 04:23:59 PM
#32
Yes of course - the 30 amp circuit would need 10 AWG wire, but you don't need to run #10 to each rig. It would only go to the PDU(s). From there, you get a pigtail rated for 15 or 20 amps to feed the PSU(s) on each rig.

Well water - I suppose you could pump it up, circulate it thru a heat exchanger, and then dump it back down the well, but that seems like it would be very prone to bad things growing (bacteria, algae, etc) from the heat. Not to mention that it would re-heat the intake water, although I'm not sure to what extent.
donator
Activity: 1731
Merit: 1008
March 28, 2012, 03:00:38 PM
#31
What are your water rates?  If you don't care about dumping it down the drain...

Even if water was free,  It cost a shitload to purify water. What a polluter you are. (tap water that is.)
donator
Activity: 1731
Merit: 1008
March 28, 2012, 02:48:00 PM
#30
I've read this whole thread and at ~5 places I saw suggested to use 30A breakers. ... You SHOULD NOT increase the breaker size without increasing the wire size.
It would be more than stupid to use a +20amp breaker on 14 awg wire and feel good about following the 80% load rule.

Know what you 15A worried guys gonna do ?

Convert your 110v outlet to a 220v by adding a breaker to the neutral and be done with it!

That's a 10min - cost nothing job. As said, we talking 15k$ per box ,,, just call an electrician !

Sure. Just a few notes:

a) The breakers must have their handles tied together, per code. Easier to just get a dual pole breaker. Few bucks extra.
b) The neutral wire must be clearly marked on both ends to show that it is hot.
c) You must replace the wall outlet with a 240-only receptacle, such as 6-15R or 6-20R. Few more bucks.
   1) If the wiring is 14 gauge, you must use no more than a 15 amp dual breaker, and a 6-15R receptacle.
    2) If the wiring is 12 gauge, you must use no more than a 20 amp dual breaker, and a 6-20R receptacle.

d) This assumes that the rig supports 240v, which it should if it is using a standard PSU. You may need to chop off the plug end and install a 6-15P or 6-20P plug.

Hope this helps anyone that is planning to be cheap with their infrastructure upgrades. Grin
legendary
Activity: 1512
Merit: 1000
March 28, 2012, 02:20:13 PM
#29
What are your water rates?  If you don't care about dumping it down the drain...



I don't know that I would feed one off a well, might run it dry, although I know some people who do and it hasn't been an issue for them (yet).

There were some guys I knew once that were doing some things.  They used these religiously to cool small rooms containing upwards of 10KW/hr of light generating equipment.

Water goes in, water comes out.  The room stays cool, can't explain that!
rjk
sr. member
Activity: 448
Merit: 250
1ngldh
March 28, 2012, 11:05:34 AM
#28
BTW, I have a bunch of these left over, if anyone wants them. Grin

donator
Activity: 1218
Merit: 1079
Gerald Davis
March 28, 2012, 11:03:27 AM
#27
commone D&T  your going round and round....
I don't think I am, I honestly have no idea what you are talking about anymore or what you are confused by.  Given you seem to be a smart guy I think I am being played so I will stop.

Quote
issue is.  powing our rigs with 220.    I just wire regular 20amp outlets with 220 and use the supplied power cord for the PSU.  

ONE LAST TIME.  

a) that is a code violation

b) why?
110V @ 15 = good for 1 rig.
220V @ 20A = good for multiple rigs.
220V @ 30A = good for 50% MORE rigs at not much more cost.

if you are plugging 1 rig into the wall you don't need 20A OR 220V.

Quote
How do you plug in your PSU's to the 220 ?
I explained it up thread... twice with both diagrams and pictures and links.  I don't really know how to explain it anymore.  The OP understood on the first try.
rjk
sr. member
Activity: 448
Merit: 250
1ngldh
March 28, 2012, 11:00:03 AM
#26
No such cable exists because there is no PSU which uses that much power.

The cord you are looking for is a C13 to C14.  They cost about $1 to $3 in bulk.
http://www.monoprice.com/products/subdepartment.asp?c_id=102&cp_id=10228#1022805

30A outlet -----> 30A PDU (fancy name for powerstrip Smiley ) -----> 5 to 10 rigs

If you just want to plug 1 rig into each outlet then you don't need 20A.  Plain ole 110V @15A is more than enough to power a single rig. Huh
Exactly. And since I don't have a PDU, this is what I did:



Chopped the end off and put on a 15 amp 240v plug. With a PDU, you can use the link from DeathAndTaxes, above.
legendary
Activity: 1876
Merit: 1000
March 28, 2012, 10:58:52 AM
#25
They do but why would you want 110V?


you dont:  my original post:

I would only add that you do not need new cords, you can wire regular plugs for 220.  Just make sure you mark them very well so you dont plug a fan or a light into them.

Not a good idea as it is a code violation, you risk voiding your insurance policy, and open yourself up to liability.  Given how cheap the proper outlet compared to the total cost (equipment, lease, cooling) of 24 GH/s farm just use the right outlet.

Quote
also, I would use a commercial grade 20 amp outlet when wiring for 220.
Which is why I said why 20 when 30 is almost as cheap at which point you is 20A 110V exists.

and how much would 25 special power supply cords?  

I did not even see (not that I looked very hard)   cords with  30amp plug ->  PSU

What PSU needs 6KW+?

The cord you are looking for is a C13 to C14.  They cost about $3.

30A outlet -----> 30A PDU (fancy name for powerstrip Smiley ) -----> 5 to 10 rigs

If you just want to plug 1 rig into each outlet then you don't need 208V/240V or even 20A.  Plain ole 110V @15 is more than enough to power a single rig. Huh

commone D&T  your going round and round....

issue is.  powing our rigs with 220.    I just wire regular 20amp outlets with 220 and use the supplied power cord for the PSU. 

How do you plug in your PSU's to the 220 ?


donator
Activity: 1218
Merit: 1079
Gerald Davis
March 28, 2012, 10:51:40 AM
#24
and how much would 25 special power supply cords?  

I did not even see (not that I looked very hard)   cords with  30amp plug ->  PSU

No such cable exists because there is no PSU which uses that much power.

The cord you are looking for is a C13 to C14.  They cost about $1 to $3 in bulk.
http://www.monoprice.com/products/subdepartment.asp?c_id=102&cp_id=10228#1022805

30A outlet -----> 30A PDU (fancy name for powerstrip Smiley ) -----> 6 to 8 rigs
1 outlet for 12 to 14 GH/s

If you just want to plug 1 rig into each outlet then you don't need 20A.  Plain ole 110V @15A is more than enough to power a single rig. Huh
legendary
Activity: 1876
Merit: 1000
March 28, 2012, 10:45:43 AM
#23
They do but why would you want 110V?


you dont:  my original post:

I would only add that you do not need new cords, you can wire regular plugs for 220.  Just make sure you mark them very well so you dont plug a fan or a light into them.

Not a good idea as it is a code violation, you risk voiding your insurance policy, and open yourself up to liability.  Given how cheap the proper outlet compared to the total cost (equipment, lease, cooling) of 24 GH/s farm just use the right outlet.

Quote
also, I would use a commercial grade 20 amp outlet when wiring for 220.
Which is why I said why 20 when 30 is almost as cheap at which point you is 20A 110V exists.

and how much would 25 special power supply cords? 

I did not even see (not that I looked very hard)   cords with  30amp plug ->  PSU
donator
Activity: 1218
Merit: 1079
Gerald Davis
March 28, 2012, 10:37:09 AM
#22
They do but why would you want 110V?


you dont:  my original post:

I would only add that you do not need new cords, you can wire regular plugs for 220.  Just make sure you mark them very well so you dont plug a fan or a light into them.

Not a good idea as it is a code violation, you risk voiding your insurance policy, and open yourself up to liability.  Given how cheap the proper outlet compared to the total cost (equipment, lease, cooling) of 24 GH/s farm just use the right outlet.

Quote
also, I would use a commercial grade 20 amp outlet when wiring for 220.
Which is why I said why 20 when 30 is almost as cheap.  Then at which point you said 30A 110V doesn't exist. It does but not sure what that has to do with 20A vs 30A on 208V/240V.
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