I have a question maybe you guys can answer. I'm thinking of setting up a 300 - 400 thash farm, what do people use to deliver power to that many systems? I mean I have no real problem using 80 of the IBM 2880W PSUs if I have to, I was just wondering if there's a more efficient answer out there.
Wow, this is a real serious project. If you do not understand anything about electricity, or, understand what I have highlighted below please seek professional help as this is not an amateur undertaking.
I am assuming a lot here, so here is my two pence worth, if it sounds a little condescending, my apologies. Your household supply is not designed to carry this load, this is a fairly serious amount of electricity and it is highly unlikely your power provider would upgrade your incoming supply.
I am also assuming your incoming power supply is 230V line to neutral, and that you will be drawing the full current on your 80 power supplies: -
1. You will be using an industrial building for this venture; I hope and not a garage?
2. You will need a three phase balanced power supply to cope with the 348 amps current draw. If your pF goes lower than the manufacturer's power supply stated 0.97 pF then you will end up by paying more for your electricity. Power factor correction capacitors are expensive but would pay for themselves in time. Industrial power rates will also work out cheaper than any household power rates anyway.
3. You will need a large distribution board with a main breaker and lots of MCCB's to split the load into safer current levels along with conduit, cabling buttress boxes and power sockets.
4. I hope you are in a really cold climate, as this current draw is like having over 140 - 2 kW heaters running all of the time.
5. You will need to make sure there is adequate separation between each unit to avoid overheating nearby units and steel racking to house them on.
6. You will need large extractor fans to remove the heat from the building and fans to draw cool air into the building.
7. You will require a huge A/C cooling unit if you are in a warm climate and that is seriously expensive to run.
8. You will need an industrial fire suppression system - remember the recent Thailand incident. You could possibly have someone monitoring the system 24/7, at a pinch with industrial fire extinguishers, but human error is something you need to factor out.
Good luck.
Thank you Thub, I appreciate the breakdown and I've thought of all of those things. In a previous life in the Navy I worked as an electrician for a couple of years while waiting for my C school to open up, so dealing with the wiring and distribution isn't a big deal, and I've already got a local contractor lined up once I finalize the building I'm going into.
From everything I've looked at however, it seems like individual PSUs are going to be what I wind up running with for a project of this size. Industrial DC voltage systems don't seem to be either the right voltage or are too expensive to be worthwhile compared to using the 2880W IBM PSUs.
Where I'm putting this, electrical cost isn't really an issue, but I'm not planning on active cooling, just going with more space (cheap) and big ass fans (also cheap). I may wind up underclocking during the couple of hot summer months (july/august) depending on operating temperatures and the space.
Fire is the biggest concern I have, I've designed a simple relay system to cut power to all the systems if a fire alarm goes off, but an installation of this size can't afford to staff it 24/7. I'll have to rely on environmental monitoring, being able to cut the power and the local fire department during off hours.