rgb@PHY.DUKE.EDU ("Robert G. Brown") (02/07/90)
Hi, there. I am a system administrator with a somewhat unusual
(but perhaps not uncommon) problem. We just obtained an SG-220S
in the big rack mount. I was somewhat surprised to learn, upon
delivery, that the rack requires 220V SINGLE PHASE power, which is
virtually non-existent in the United States.
We are trying to install it in the physics department, where we have
an abundance of three-phase 240 (which works out, if you connect across
any two "hot" leads, to be around 208V peak with a Pi/6 phase shift).
We might be able to find 240 two-phase (if we go back to the
transformer). But there just is no 220 single phase (that is, one
220V hot, one current-carrying neutral, and one cold ground) around.
SG is "installing" it for us, but the installation man has gone off to
school (literally) for a week to learn how to install it, and I would
like to at least have power for it when he returns and when he left he
was clueless as to its real power needs. If anyone out there has:
a) installed a power series rack on a three phase line;
b) installed a power series rack on a two phase line;
c) blown up a power series rack while trying to do either one;
I'd love to hear from you. A wiring diagram of any working solutions
would also be appreciated (the rack has a three prong plug -- hot,
neutral, cold).
I should note that we did try the three phase power (as a physicist, I
know that the system should NOT be able to see any real difference
between a hot-neutral pair at 208V and a hot-hot pair at 208V with a
phase difference -- unless it uses the current-carrying "neutral" as a
pseudo-ground, which is dumb).
When we did it, the machine seemed to boot, but the prom monitor did
not come up on port 1 (or 2,3 or 4). We have no graphics monitor, it
is a server--only configuration at this time. When we put a scope on
the backplane and on the serial line itself we got very unusual
things. The serial line showed a .15V, 60Hz triangular waveform on
ALL pins but 1 and 2. 1 had a more attenuated 60Hz signal, and 2 was
(relatively) quiet. Obviously this is not at all like what we found
on a functioning serial line.
So: Is our power supply bad? Is our power bad? Are any or all of
the boards bad? Are the serial ports bad? Or do we need to "flick
that little switch over there"?
Thanks,
Rob Brown
rgb@physics.phy.duke.edu
Duke University Physics Dept.
Durham, NC 27706markb@denali.sgi.com (Mark Bradley) (02/08/90)
In article <9002070129.AA12557@physics.phy.duke.edu>, rgb@PHY.DUKE.EDU ("Robert G. Brown") writes: > Hi, there. I am a system administrator with a somewhat unusual > (but perhaps not uncommon) problem. We just obtained an SG-220S > in the big rack mount. I was somewhat surprised to learn, upon > delivery, that the rack requires 220V SINGLE PHASE power, which is > virtually non-existent in the United States. The plug is a NEMA 5-15. The wiring of the power distribution box expects 110 on each of the hot and `neutral'. So it should look like this: 110VAC--- | | ---110VAC O ---GND in the USA, with the 110's 180 degrees out of phase. 220VAC single phase is what they have in Europe. We ship a different plug to Europe, too. markb -- Mark Bradley "Faster, faster, until the thrill of I/O Subsystems speed overcomes the fear of death." Silicon Graphics Computer Systems Mountain View, CA 94039-7311 ---Hunter S. Thompson ******************************************************************************** * Disclaimer: Anything I say is my opinion. If someone else wants to use it, * * it will cost... * ********************************************************************************
markb@denali.sgi.com (Mark Bradley) (02/08/90)
In article <9002070129.AA12557@physics.phy.duke.edu>, rgb@PHY.DUKE.EDU ("Robert G. Brown") writes: > I should note that we did try the three phase power (as a physicist, I > know that the system should NOT be able to see any real difference > between a hot-neutral pair at 208V and a hot-hot pair at 208V with a > phase difference -- unless it uses the current-carrying "neutral" as a > pseudo-ground, which is dumb). > > When we did it, the machine seemed to boot, but the prom monitor did > not come up on port 1 (or 2,3 or 4). We have no graphics monitor, it > is a server--only configuration at this time. When we put a scope on > the backplane and on the serial line itself we got very unusual > things. The serial line showed a .15V, 60Hz triangular waveform on > ALL pins but 1 and 2. 1 had a more attenuated 60Hz signal, and 2 was > (relatively) quiet. Obviously this is not at all like what we found > on a functioning serial line. > > So: Is our power supply bad? Is our power bad? Are any or all of > the boards bad? Are the serial ports bad? Or do we need to "flick > that little switch over there"? I replied a bit too quickly, it seems, as I did not address the rest of your questions. 220, neutral and ground will work too--you're correct on that one. As to your triangular waveforms on the serial lines; it sounds like something is wrong. Power supply is not likely to be the problem; there is no switch to flick, to my knowledge; and maybe the cabling/breakout board for the serial lines has a problem. The prom monitor *should* only come up on one port, though, and there may be no problem at all. Once the system is up, try `man getty' for info on your serial ports. markb -- Mark Bradley "Faster, faster, until the thrill of I/O Subsystems speed overcomes the fear of death." Silicon Graphics Computer Systems Mountain View, CA 94039-7311 ---Hunter S. Thompson ******************************************************************************** * Disclaimer: Anything I say is my opinion. If someone else wants to use it, * * it will cost... * ********************************************************************************
ams@ACM.PRINCETON.EDU (02/08/90)
Ok guys, which is it? Mark Bradly writes: > The plug is a NEMA 5-15. The wiring of the power distribution box > expects 110 on each of the hot and `neutral'. So it should look like > this: > > 110VAC--- | | ---110VAC > > O ---GND > > in the USA, with the > 110's 180 degrees out of phase. 220VAC single phase is what they have in > Europe. We ship a different plug to Europe, too. On page 1-1, under "Site Electrical Requirements": ALL POWER CENTER MODELS REQUIRE A DEDICATED 220 Volt single phase 30 amp power line. A dedicated line must provide 220 current in the following range: o 195-240 Volts of single phase AC o 47-63Hz A POWER Center can draw a maximum of 24 amps from the 220 Volt line (depending on configuration of the POWER Center). The POWER Center has a maximum VA of 5280. The NEMA receptacle (for domestic installations) must have the following characteristics: o NEMA L6 - 30R (250V @ 30 amps) Twist Lock This excerpt comes from "POWER Center Site Preparation" Version 1.0, Document Number 007-5310-110. --ams p.s. Markb--I don't think a 110vac on both sides of a three prong plug is a code violation. All US 220 standards I am familiar with are twist lock (circular) or triangular pattern (like on the "average family electric clothes dryer).