redundant server power supply

Thread Starter

racmaster

Joined Feb 13, 2018
29
thank you for your answer, but the question is how to connect 2 cables of AC input on 4 pins...? which cable to which pin?
 

IamJatinah

Joined Oct 22, 2014
136
Hi All, just a note on Redundant and Hot-Swap power supplies. Notice on the connection designators, there will nearly always be "precharge" or first-hit connections on the backplane. There is a specific reason for this, so consider running AC Precharge AC lines and add a switch to enable AC Mains a second after the Precharge rails are energized. Also, notice ground fingers will be close to the edge of the connector edges, again for a reason, we want to make a solid ground connection as step one, hit precharge fingers or pins second, and allow full insertion third. Removal may or may not require an acknowledge you will be removing the power unit before the actual removal, most electronically watch for Insert/Removal actions or pins, like a latch position or something not obvious to the user, but electrically considered.
The precharge rails allow a regulated charge-up of the primary sections before they power-up into an active and demanding load;o) Also, if not used in the intended frame, backplane or system, that unit may not power up on a bench alone, as most also include interlock enables that allow use in specific systems.
 

Thread Starter

racmaster

Joined Feb 13, 2018
29
thank you guys, i was loosing faith... ;)

so, to be sure i understand properly, i should make a switch which brings AC first to precharge and then after a moment bring power to A2 and A4. correct?

i want to use these PSUs as a power source to DC-DC charger, will be powered from petrol generator as AC power source. question is how to identify which one is AC line and AC neutral on the generator?
 

IamJatinah

Joined Oct 22, 2014
136
Hi again, I looked up the cage number, IBM 49p2036 for the RPS-350 enclosure that this should operate inside. Being an IBM power system, I can just about guarantee it will be a challenge to run this openly without the system connected or interfaced to run.
These power units are pretty thoughtful, and easily controlled by the host and or master system CPU. A few things I saw on the connector to look into, and I wonder why you might want this particular power supply for the outputs shown, this can be done much easier than cobbling command and interlock interfaces for this unit.
Here are the pins to research if using this outside of its designed cage.....
PSon(B8)
A0(B9)
A1(B10)
12LS, 5LS, 3.3LS (sense lines that may need to connect to a remote sense vector inside the system)
5Vsb (usually a bias supply that gets returned to the same power supply as an interlock)
PSKill (remote disconnect or kill-switch from cage system)
ReturnS (not sure what they may reference with this)
SCL (Serial Data Clock, timing when this power supply "talks" to the host, config, heating, etc)
SDA (Serial "Data" to that same host supplying data requested from host)
Vbias (powers something in the backplane specific to this unit running, alive, available)
PRESENT# (identifies to host if unit is alive, present, active and/or available)

It could be as easy as strapping 5Vsb to PSon, attach loads (DO NOT run these unloaded and expect regulation or even operations, these need active loads at powerup), apply Precharge AC, Apply Main AC, and away she goes, or as aweful as manipulating pins.

Input wiring notes - usually AC N is tied to Gnd at the service transformer, but just remember AC N to precharge and main N, and AC L to precharge L and main L.

I might consider a different power supply if you are looking for +12v, +5v, +3.3 at 20A or so each or build one up. These are intelligent supplies for a few reasons, not too easy for projects. Thoughts? ;o)
 
Last edited:

Thread Starter

racmaster

Joined Feb 13, 2018
29
the reason is simple, i just dont have any other psu.... if thats possible to use these, i would go for it. if there is a easier way how to use them, or use rebuild them to provide 12v output, you are welcomed... i need only 12v output.
 
Top