On Fri, 5 Mar 2004, Bob Hoffman wrote:

> On Fri, 5 Mar 2004, Christopher Zach wrote:
>
> > RP's typically didn't have it, but the RP series were typically
> > hard-wired into power and ran on their own breakers. RS03/04 drives also
> > had the sequencers (and I believe they were MASSBUSS).
>
> RP0x drives in the USA had their power daisy-chained from one drive to the
> next in groups of three. That is, the first drive plugged into a 30
> amp, 3-phase outlet (NEMA L21-30), the second drive plugged into the
> first and the third drive plugged into the second. If there was a 4th
> drive, it was plugged into a separate 3-phase circuit.
>
> As the power passed through each drive in the chain, the phases were
> rotated so that each drive's motor ran off a different phase in order to
> balance the load.

Huh? The RP drives use two phase motors, so while you didn't pull 3 times
what one drive used doing that, you did double it.
The dirves are connected to 3-ph power, but the motors use just 2-ph.

Johnny

Johnny Billquist || "I'm on a bus
|| on a psychedelic trip
email: bqt@update.uu.se || Reading murder books
pdp is alive! || tryin' to stay hip" - B. Idol
----------
To unsubscribe (or subscribe) from (to) this list, send a message to
info-pdp11-request@village.org, with the first line of the message
body being "unsubscribe" or "subscribe", respectively (without the quotes).