19 Jun
2014
19 Jun
'14
8:34 a.m.
On 06/19/2014 02:47 AM, cctalk-request at classiccmp.org wrote:
Hi Sean,
No three-phase available nearby so if I ever do need it I'll be using a rotary
converter or VFD or something.
Luckily I don't need it at the moment.
It will likely have it's own transformer and drop.
I'm sure it will be at least 200A service.
There are only a VERY few devices
that can be connected to a
PDP-11
that need 3-phase power. One I know of is the RP07, but that is
really a VAX peripheral. Since it is Massbus, it COULD be
connected to
an 11/70, though. Possibly also the RP06 might also be 3-phase.
In general, though, these machines are QUITE low power
compared to
higher-end machines like PDP-10's and early VAXes. I can't
imagine
any PDP-8 system that needs much power. Unless it was loaded
with a BUNCH of RK05 drives, I can't imagine it wouldn't run off
a single 120V 15A outlet.
The PDP-11/45 draws enough power it would need separate outlets
for the CPU and the drives.
Jon
19 Jun
19 Jun
9:15 a.m.
New subject: Electric And AC Sizing For New Building Housing PDP-8s, and PDP-11s
Just thought I'd throw it out there as something for consideration... the
biggest mini I have is an 11/34a and that runs on single-phase no problem,
but I know some guys out there have much larger pieces of equipment... my
ROLM SCBX is "only" what, six or seven shelves of TTL (maybe 70% full?) and
analog circuitry across two racks, and that wants three-phase to run as
configured at the factory.
Best,
Sean
P.S. Any old ROLMen on the list?? I could use some help rustling up some
documentation for 8000-series CBX... ;)
On Thu, Jun 19, 2014 at 11:34 AM, Jon Elson <elson at pico-systems.com> wrote:
On 06/19/2014 02:47 AM, cctalk-request at
classiccmp.org wrote:
Hi Sean,
No three-phase available nearby so if I ever do need it I'll be using a
rotary
converter or VFD or something.
Luckily I don't need it at the moment.
It will likely have it's own transformer and drop.
I'm sure it will be at least 200A service.
There are only a VERY few devices that can be connected to a PDP-11
that need 3-phase power. One I know of is the RP07, but that is
really a VAX peripheral. Since it is Massbus, it COULD be connected to
an 11/70, though. Possibly also the RP06 might also be 3-phase.
In general, though, these machines are QUITE low power compared to
higher-end machines like PDP-10's and early VAXes. I can't imagine
any PDP-8 system that needs much power. Unless it was loaded
with a BUNCH of RK05 drives, I can't imagine it wouldn't run off
a single 120V 15A outlet.
The PDP-11/45 draws enough power it would need separate outlets
for the CPU and the drives.
Jon
10:58 a.m.
New subject: Electric And AC Sizing For New Building Housing PDP-8s, and PDP-11s
The Microdata 1600 system cabinets in the time up to 1976 used a Hubble
30 amp thru bulkhead connector. It was banned, and in the subsequent
design the power had to be reduced to a 20 amp level.
This had to do with what circuits could be used in commercial
operations, not what connectors were available.
The cabinet redesign also took into account fitting the systems into
Boeing cargo containers, and also on some commercial flights. Up to
that time they had to be trucked because they were too tall.
They also made it possible to pull the power supply, which was still a
linear design as a module and swap it. It was still a huge pain in the
butt to do so, but they tried.
On 6/19/2014 9:15 AM, Sean Caron wrote:
Just thought I'd throw it out there as something
for consideration... the
biggest mini I have is an 11/34a and that runs on single-phase no problem,
but I know some guys out there have much larger pieces of equipment... my
ROLM SCBX is "only" what, six or seven shelves of TTL (maybe 70% full?) and
analog circuitry across two racks, and that wants three-phase to run as
configured at the factory.
Best,
Sean
P.S. Any old ROLMen on the list?? I could use some help rustling up some
documentation for 8000-series CBX... ;)
On Thu, Jun 19, 2014 at 11:34 AM, Jon Elson <elson at pico-systems.com> wrote:
On 06/19/2014 02:47 AM, cctalk-request at
classiccmp.org wrote:
Hi Sean,
No three-phase available nearby so if I ever do need it I'll be using a
rotary
converter or VFD or something.
Luckily I don't need it at the moment.
It will likely have it's own transformer and drop.
I'm sure it will be at least 200A service.
There are only a VERY few devices that can be connected to a PDP-11
that need 3-phase power. One I know of is the RP07, but that is
really a VAX peripheral. Since it is Massbus, it COULD be connected to
an 11/70, though. Possibly also the RP06 might also be 3-phase.
In general, though, these machines are QUITE low power compared to
higher-end machines like PDP-10's and early VAXes. I can't imagine
any PDP-8 system that needs much power. Unless it was loaded
with a BUNCH of RK05 drives, I can't imagine it wouldn't run off
a single 120V 15A outlet.
The PDP-11/45 draws enough power it would need separate outlets
for the CPU and the drives.
Jon
10:15 a.m.
New subject: Electric And AC Sizing For New Building Housing PDP-8s, and PDP-11s
On Jun 19, 2014, at 11:34 AM, Jon Elson <elson at pico-systems.com> wrote:
I?m pretty sure an RP06 requires 3 phase power, and chances are the same goes for RP04,
RP05 and perhaps RM02/03. The manuals would say, of course.
I remember that the RP06 or its brothers uses 3 phase power because of warnings that the
phases have to be hooked up right or the pack will unscrew at powerup (due to spinning in
the wrong direction).
paul
...
There are only a VERY few devices that can be connected to a PDP-11
that need 3-phase power. One I know of is the RP07, but that is
really a VAX peripheral. Since it is Massbus, it COULD be connected to
an 11/70, though. Possibly also the RP06 might also be 3-phase. 
12:12 p.m.
New subject: Electric And AC Sizing For New Building Housing PDP-8s, and PDP-11s
On Jun 19, 2014 11:27 AM, "Paul Koning" <paulkoning at comcast.net>
wrote:
I remember that the RP06 or its brothers uses 3 phase
power because of
warnings that the phases have to be hooked up right or the pack
will
unscrew at powerup (due to spinning in the wrong direction).
There might be other drives that do that, but not the RP06 (or RP05). The
US model is wired for 120/208V three phase Y power. They run a single phase
motor between two phases (208V), and the power supply for the logic between
a phase and neutral (120V). Nothing in it depends on the phase ordering.
They have an outlet for chaining power to a second drive (but not more than
one), and they do rotate the phases between the inlet and outlet.
The motor is rated to run on up to 240V nominal, so it can easily be wired
to run on 120/240V split phase if three phase is not available.
3839
days inactive
3839
days old
4 comments
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elson＠pico-systems.com -
jws＠jwsss.com -
paulkoning＠comcast.net -
scaron＠umich.edu -
spacewar＠gmail.com