19 Jul
2016
19 Jul
'16
10:51 a.m.
Right... and in my area (hardly unique, I'd
wager), you cannot get
3-phase in residential areas. The shared transformers on the poles
don't provide it and you can't pay them to add/change a transformer.
You have to be in a commercial area to get that. Fortunately for me,
my tastes in minicomputers runs "small", so my largest machines have a
30A 110V single-phase plug (frequently to an H-861, but not always).
The Cray is single phase, the only thing I've ever owned that was 3 phase
was the laser stuff. Now my solid state laser projector uses 100 watts and
producsed half the power of the argon that used to take 3ph @ 30A (and
still tripped the breaker sometimes.)
I've heard sometimes the utility will indeed give you 3phase but you have
to pay them to replace the transformer and it's very very expensive.
Normally it's people buying used milling equipment that are after it from
my experience. There are rotary converters and solid state converters but
probably not ideal for huge loads.
The Cray uses 5 x Pioneer magnetics power supplies that I believe are
identical to those in the Sun E10000. The smaller rack with the VME
chassis and hard drives -- good chance the power supplies are okay with
110/120v. The disk trays at least are just good quality SMPS that do 5/12
in each drawer (was 4 x 9GB full height disk per drawer.)
The Pioneer Magnetics supplies that run the computational part are like
48vdc out @ 5000W each.... so not sure if they would run on 120V but if so
-- it would be a real high amperage load.
Note - in the modern datacenter in the US it's not uncommon for everything
to be run on 208, but everything would run on 120.
--
Ethan O'Toole