Post
Topic
Board Hardware
Re: My new garage and 200 amps
by
nanook7
on 08/08/2014, 04:31:28 UTC
Well nobody runs a 1200W PSU @ 1200W of load.  30A is good for 5760W (after 20% derate).   30A PDU are dirt cheap if you are willing to buy used.   Datacenters go through tens of thousands of these so there is never ending supply.

http://i.ebayimg.com/00/s/NDIwWDc1MA==/z/cRYAAOSwxCxT4ECL/$_1.JPG

AP9571 is one example but there are plenty of other models which work equally well.  New ones are $150+ but used ones tend to go for $30 to $50 each.  A basic PDU is pretty much a high current power strip with a breaker.  It pretty much works or it doesn't so I have never had a problem buying used.

You will need to install* a 30A double pole breaker and NEMA L6-30R outlet for each one.  The AP9571 comes prewired with a matching NEMA L6-30P plug.  By the NEC, continual loads are derated 20% so you only get 24A usable from a 30A branch circuit.  One circuit (breaker, branch wiring, outlet, pdu) is good for 5.76KW (240V * 30A * 80%) which is probably more than most people can handle.  Remember electricity in = heat out.   So for those with dreams of building 100KW farms I would say start "small" you can build out in 5.76KW segments.  Even 5.76KW is a lot of heat.


* I can be done DIY, I put two in so I could power a 11KW GPU farm but this isn't a beginner project.  Remember electricity kills instantly and without warning.  Parts on the inside of the circuit breaker panel may remain energized with lethal voltage even if breakers are off.  It isn't a nuclear reactor but it does require some competence and good tools never hurt.

I know these datacenter PDUs are suppose to be feed 208V but if we feed them 240V will they still work and work without failure?