Anything special about converting VAX 11/780 to single phase?

From: Gunther Schadow <gunther_at_aurora.regenstrief.org>
Date: Sun May 12 22:18:14 2002

Hi Matt and all,

now I'm getting there, my family is gone to Germany again
so I can mess up the house. I am getting ready to hook up
my VAX 11/780, UNIBUS cabinet, TE16 and TU78, move the other
VAX6000 into the basement, run CI cable between the garage
and the basement etc. I need some more ideas about the power
situation.

As I said I have that two-phase 220 V line running through my
garage and down into the basement. I'm going to splice off
a minor branch. This is not going to be NEC proper, but I
need the 60 A rating for the VAXen in both places. May be at
some point I have figured out the exact load balance and then
I'll put in distributor panels with proper circuit breakers
on the branch circuits.

So, the following is what I plan for wiring up the 11/780:


>> ---phase1----------+--- P1
>>
>> ---phase2----------+--- P2
>> |
>> +--- P3
>>
>> ---neutral------------- N
>>
>> ---ground-------------- GND

Matt, you were suggeting to screw off the fuses F2 and F3
in order to protect this shutdown interlock gizmo? What's
the exact situation here? I am kind of lazy about removing
the power distributor box and look for myself, because it's
all so nicely mounted right now. I even have taken the
power outlet box with me when we removed the machine from
it's original site, so, all I'm going to do is wire things
in the power outlet box and then everything else will just
plug in.

While we are at it, is there a good standard way of splicing
a branch from a wire without cutting the wire? This one is a
#6 wire, a real hassle to mess with, and I don't have any
spare length. So, I was hoping to find a T-piece connector
to just interpose:

                ______________
     ================ ==================
                ~~~~+ || +~~~~
                    | || |
                    | || |
                      ||
                      ||
                      ||
                      ||

and then tie the wires in the T-piece with a nice and clean
screw each, instead of such messy twist-on caps. Ideally, the
T-piece would be covered in an insulating plastic shell. But
such T-pieces were nowhere to be found at my home-improvement
store. So, I settled with taps, the size of a fat bolt with
a deep notch and a nut with a kind of a wedge. This I can
put over the wire without cutting it and so I can clamp the
lines of the branch in. It's going to be quite some fiddling
but it's the best I could come up with. Any better ideas?

thanks,
-Gunther


--
Gunther Schadow, M.D., Ph.D.                    gschadow_at_regenstrief.org
Medical Information Scientist      Regenstrief Institute for Health Care
Adjunct Assistant Professor        Indiana University School of Medicine
tel:1(317)630-7960                         http://aurora.regenstrief.org
Received on Sun May 12 2002 - 22:18:14 BST

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