Running 3 phase 780s on single phase power (was RE: hams on classiccmp)
Paul_Koning at Dell.com
Mon Jan 19 12:45:16 CST 2009
>>>>> "Ian" == Ian King <IanK at vulcan.com> writes:
Ian> Um, let's clarify something: there are NO three-phase components
Ian> in a VAX-11. The switchers, the fans, ALL of it are single
Ian> phase. Oh, there is one component that's "three phase": the
Ian> power supply in the PDU itself, which generates the voltage to
Ian> run the relay that switches the switched outlets. That's fused
Ian> separately. And yes, the neutral leg has a breaker, too.
Ian> And yes, this IS a "full config", with RH780, DW780, CI780 and
Ian> (lucky us!) FP785.
Some peripherals are real three phase, though; the RP06 comes to mind.
A breaker in a neutral is odd. I guess it's legal IF it's part of a
set of tied-together breakers, so that tripping the neutral breaker
also opens the phases.
I wonder why they didn't use 3-phase power supplies; that would save
space for the filter capacitors.
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