-------- > (I recall that correct wiring of the phases / phase rotation was very > important vis a vis backup power sources for data centres.)
For anything but resitive heating, you 100% want to have the order of your three phases under tight control (said the 14 year old kid who fixed the frayed cable on the grain elevator, only to have it run backwards :-) If you have multiple power feeds for redundancy, you will also have to care about not only their order but also the absolute phasing between them - ie "rotating" the three phases of one feed to align them. But depending on the local circumstances, that may still leave you with too much phase-skew and you will have to install a "W" transformer to twist one of the feeds 30 degrees. If you're going "Say what ?!" it is fully understandable, but yes, you can rotate the phase between primary and secondary in steps of 30 degrees with a three phase transformer: https://electrical-engineering-portal.com/understanding-vector-group-transformer-1 Many data-centers these days bypass all that trouble, by having separate HVDC busses for each feed, so that they only have to synchronize the "internal" grid, but that takes us into serious high power EE. -- Poul-Henning Kamp | UNIX since Zilog Zeus 3.20 [email protected] | TCP/IP since RFC 956 FreeBSD committer | BSD since 4.3-tahoe Never attribute to malice what can adequately be explained by incompetence. _______________________________________________ time-nuts mailing list -- [email protected] To unsubscribe, go to http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com and follow the instructions there.
