On 6/22/20 2:11 PM, Joe Monk wrote:
Well its pretty simple. Each phase has a 0 degree point for the rise
and fall of the sine wave. You wire each phase to its corresponding 60
degree out connection on the relay coil. So, if the phases dont line
up, you dont get a strong enough magnetic field
mån 2020-06-22 klockan 14:05 -0600 skrev Grant Taylor:
> On 6/22/20 1:09 PM, William Donzelli wrote:
> > 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
alf 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.
718.921.2620 (O)
917.572.7364 (C)
d...@bkassociates.net
-- Original Message --
From: "William Donzelli"
To: IBM-MAIN@listserv.ua.edu
Sent: 22-Jun-20 15:09:50
Subject: Re: 3 phase power question for the gray hair group. :-)
Yes its true, but before you let a disk spin back
Well its pretty simple. Each phase has a 0 degree point for the rise and
fall of the sine wave. You wire each phase to its corresponding 60 degree
out connection on the relay coil. So, if the phases dont line up, you
dont get a strong enough magnetic field to close the relay.
Joe
On Mon, Jun 22,
On 6/22/20 1:09 PM, William Donzelli wrote:
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
> 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
> DC rules
AC rules are harder, because of the extra Z.
--
Will
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DC rules
On Tue, Jun 23, 2020, 04:33 Paul Gilmartin <
000433f07816-dmarc-requ...@listserv.ua.edu> wrote:
> On Mon, 22 Jun 2020 16:30:01 +, Doug wrote:
>
> >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
On Mon, 22 Jun 2020 16:30:01 +, Doug wrote:
>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
There was a SHARE presentation early 80's by the 'Fat Boys' from Quantico that
tried to plug a Siemens 3-phase printer into a 4361. I don't know/remember what
they did wrong but they had load of pictures of blown out T05 cans from the CPU.
In a message dated 6/22/2020 11:05:28 AM Central
.ua.edu
Sent: 22-Jun-20 12:03:59
Subject: Re: 3 phase power question for the gray hair group. :-)
On Mon, 22 Jun 2020 15:34:37 +, Pommier, Rex wrote:
I have a light - probably trivia by now - question for those of you who have
been around a while. My earliest experience with IBM disk was 338
fwiw, a 3-phase motor rotates with the phase order it gets. As mentioned,
the wrong direction would presumably be a very bad thing for disk drives,
so they don't let it happen. Anyone else's guess on the rest of the
electronics.
sas
On Mon, Jun 22, 2020 at 12:01 PM William Donzelli
wrote:
>
On Mon, 22 Jun 2020 15:34:37 +, Pommier, Rex wrote:
>
>I have a light - probably trivia by now - question for those of you who have
>been around a while. My earliest experience with IBM disk was 3380s. They
>ran 3 phase power, and if the phases weren't cabled correctly, the machine
All three phase IBM stuff from that era I have seen have phase
rotation sensors, and will simply not go through the proper power
sequence unless everything is fine.
--
Will
On Mon, Jun 22, 2020 at 11:35 AM Pommier, Rex wrote:
>
> Hi group,
>
> I have a light - probably trivia by now - question
Hi group,
I have a light - probably trivia by now - question for those of you who have
been around a while. My earliest experience with IBM disk was 3380s. They ran
3 phase power, and if the phases weren't cabled correctly, the machine wouldn't
power up. I seem to recall hearing stories of
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