Topic: Power Configuration [BOUNTY 5BTC] - page 2. (Read 5705 times)

Yeah that was my point.  
Per the link 12A. The OP would need 5x of those = $500+.
Also that is a metered not switched PDU.  Switched version is double so it is more like $1000+.

vs

30A (24A derated) "basic" used PDU = $50.

I didn't say they don't exist .... I said they are expensive.

I've thought about using a subpanel but decided against it since I found a single PDU that can can distribute the load and I'm assuming that installing subpanel will be much more expensive than changing a socket. I tried to find a network controlled 50 Amp non-three phased PDU and couldn't find it.

I believe the OC for the 7970 costs less than 50Watts per card and gives a 165 MHash improvement. If I didn't OC the entire farm i'd save 1800 Watts and loose 5940 MHash over all 9 machines. If I was to add an additional machine that would take 1000 Watts and provide an additional 2220 MHash. My power would be reduced by 800 watts and I would loose 3730 MHash even with the the additional machine in an non OC senario. In todays market that would net me a loss of $315 a month. As long as 7 cards don't die within a year i'm more profitable with the OC then otherwise.

 

How much wattage do you need?  Is 5.76 KW enough?  If so you can do it for <$100.

30A single phase is going to be the cheapest bang for the buck.  You get used one for <$50 on ebay (sometimes <$30 shipped if you wait for deals).

Those California Connectors are insanely expensive.  I would avoid them like the plague unless your local code PROHIBITS NEMA-6.  Most places simply recommend the CA connector over NEMA-6.  You could have electrician rewire it for NEMA 6 configuration (hot, hot, ground) which is going to be a lot cheaper setup.  It will require changes at both the outlet and the breaker but should be pretty routine.  
If you can get by with 5.7KW (or have multiple outlets which can be rewired I would do this)

1) Replace the NEMA 10-50 with a NEMA 10-30 outlet. ($15 in parts)
2) Buy a AP9571 PDU.  They are cheap on ebay ($50 tops sometimes a lot less).
3) Do the wiring yourself it honestly isn't very hard or pay an electrician to do it (but I would shop around, rewiring an outlet is a <1 hr job - he is burning you for ~$600/hr to $100/hr)
4) Buy some standard C13 to C14 cables ($4 ea)

Why the AP9571?  Beacause APC made a quadrillion of them so used ones as always on ebay.
208V/240V.
30A (24 derated)
12 C14 outlets
Single NEMA L6-30P plug with 20ft very very thick cord.

Pretty much no PDU gives you a lower cost per KW.

Here is an example:
http://www.ebay.com/itm/APC-Basic-Rack-Mount-PDU-1U-AP9571-208VAC-30A-IEC-320-12-C13-NEMA-L6-30P-/130672139930?pt=LH_DefaultDomain_0&hash=item1e6caa9e9a

If you need more than 5.76KW (or want to later expand) I would install 2x NEMA L6-30 outlets.
Does the property have 2x NEMA-10 outlets?  If so then you can go to 11KW for ~$220 (plus optionally electrician labor).  The other option (and no this isn't code compliant) would be to have electrician install a NEMA L6-50 outlet and then wire a Y adapter using a NEMA L6-50 socket and 2x NEMA L6-30 plugs.  There is no danger BUT if you want to be safe ensure the combined load of the 2x PDU is <40A.

On edit: I see you indicated needing 49A.  To be code compliant no 50A PDU will allow 50A of draw.  They are derated 20%.  US Electrical code prohibits using more than 80% of circuit rated capacity for continual loads.  So 50A PDU will have an internal circuit breaker at 40A (likely 2x 20A breakers).

I have one of these Tripplite PDU's (first link) running off of 240v.  I found it on sale for under $300, right now this one is $519 but still cheaper than the option you are looking at. Although I did buy all my power cords from Stayonline.com, happy with the purchase from them. I have mine hooked up to network, to my surprise this device does not tell you how much power each port uses, the led on the bank will only tell you how many amp each bank uses. I felt the interface and features were really lacking. In my case 3.8GH using 7amp. Max of this device is 24amp.

http://www.amazon.com/Tripp-Lite-PDUMH30HVNET-Distribution-Switching/dp/B0013HY9E2/ref=sr_1_14?s=electronics&ie=UTF8&qid=1333123661&sr=1-14

If I had it to do over I would probably go with the cheaper version without the network monitoring for $257.  It has been stable and just never use that feature.

http://www.amazon.com/Tripp-Lite-PDUMH30HV-Metered-L6-30P/dp/B0053YIUPK/ref=sr_1_12?s=electronics&ie=UTF8&qid=1333123661&sr=1-12

Insanely expensive.  Remember PDU are rated on maxed switched capacity and even 5 KW PDU are $500+.

Oops, my bad I didn't notice that. Yeah single phase PDUs above 30 amps are rare, but as another poster mentioned, maybe a subpanel would be a good idea.

I've chosen to go with a licensed electrician since I'm leasing the office space. I don't want to take any chances and cause a fire.

The part the I'm most confused by is Three Phased solutions. From what I hear it's best to stay away from it. I believe my existing NEMA 10-50 Outlet is not three phase and that's why I'm looking at Geist ZP090-105C19CS6 50 Amp PDU since it does not require it. Both items you found on EBay are three phased.
In my research I found that almost every solution above 30 Amps seemed to be three phased. The Geist was the only PDU that I could find that worked on a normal circuit.

Well for one thing, you ought to be able to replace that outlet yourself, that would save you a bit. Unless there is some regulation that says you aren't allowed to, or that you have to be licensed?

The PDU is a good idea, but damn that is expensive.  

EDIT: Some alternatives on ebay:

1: http://www.ebay.com/itm/200732820785
2: http://www.ebay.com/itm/310391058869

and others.

I'm about to spend a bunch of cash in an area that I'm not familiar with. I've done a bunch of research and would like your help. I'll donate 5 BTC to whoever can confirm my approach or suggest a better solution.

I will be running 9 mining rigs each with 4x7970s pulling just about 1150 watts each via two 750 Watt Power supplies. I've calculated that at 208 Volts that each machine will pull 5.53 amps or 49.76 amps to support all 9 machines.

I've been fortunate enough to get a lease that includes electricity and A/C. The office suite comes with a NEMA 10-50 Socket 50 Amps @ 250V. I've contracted an electrician to replace the outdated NEMA Socket with a CA STD CS8265C (California Style 50 Amp, 250 Volt, 3 wire Twistlock Plug). That will allow me to use the Geist ZP090-105C19CS6 50 Amp PDU (http://www.stayonline.com/detail.aspx?ID=13298). I will then use C20 to 2 Way C13 cord (http://www.stayonline.com/detail.aspx?ID=18940) to plug in each of the powers supplies (two to each rig).

It's going to run me $919 for the PDU/Power cords and about $400 for the electrician to change out the power socket. Is this the best way to go or is there a better option?