> h:\Vendors\ArcaNoae\firefox\005B_01.TRP If you still have them, please consider scanning them for bitsavers.org.
-- Shmuel (Seymour J.) Metz http://mason.gmu.edu/~smetz3 ________________________________________ From: IBM Mainframe Discussion List [IBM-MAIN@LISTSERV.UA.EDU] on behalf of William Donzelli [wdonze...@gmail.com] Sent: Monday, June 22, 2020 3:09 PM To: IBM-MAIN@LISTSERV.UA.EDU Subject: Re: 3 phase power question for the gray hair group. :-) > Yes its true, but before you let a disk spin backwards, you checked the > fans in the logic gate, they were 3 ph too. Depending on how they spun > (clockwise or counterclockwise), you had the phases corrected. I never > spun up a drive that went backward using that technique. > And if it was say a 2365, or a 2860 or 70, it would power up just fine, > then get a thermal since the fans were spinning in the wrong direction. Are you sure about the fans in the gate being three phase? Standard practice for IBM (or pretty much every other computer manufacturer) was to use single phase fans, just tied across the phases in a nice balanced matter. Don't make me break out the Big Blue Binders... Also, if I could post an image to this list, I would show what a standard IBM phase rotation sensor looks like. I have a box of them. They are basically just relays with three windings on the core, and unless the phases are hooked up properly, they will not throw - all the magnetic fields have to line up. -- Will ---------------------------------------------------------------------- For IBM-MAIN subscribe / signoff / archive access instructions, send email to lists...@listserv.ua.edu with the message: INFO IBM-MAIN ---------------------------------------------------------------------- For IBM-MAIN subscribe / signoff / archive access instructions, send email to lists...@listserv.ua.edu with the message: INFO IBM-MAIN
