Cray J932SE (was Re: Straight 8 up on Ebay just now)

Ethan Dicks ethan.dicks at gmail.com
Tue Jul 19 12:14:15 CDT 2016


On Tue, Jul 19, 2016 at 12:53 PM, Mouse <mouse at rodents-montreal.org> wrote:
>> [...], especially since most electrical installations (even domestic)
>> are 3-phase.
>
> This, I believe, must be location-specific.  In North America, it is
> usual for domestic electrical feeds to be only two-phase (that is, they
> are the two sides of a centre-tapped secondary - the two hot wires are
> 180 degrees out of phase with one another).

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).

Code in my area allows for homeowners to do some of their own wiring,
but for projects larger than, essentially, outlet and toggle-switch
replacement, permits are required (but enforcement is, of course,
negligible unless something goes horribly wrong).  They did just amend
code locally to _prohibit_ landlords from self-repair of electrical
(and I think gas and plumbing) in rental properties, because of
several high-profile fires caused by inexpert work.  So you can work
on your own domicile, but not your tenants'.

-ethan


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