Hardware reference guide

Pwr. & Grnding. Guide
35013379 11/2011 743
Use only like summable power supplies (same product reference) except for
140CPS11410 and 140CPS11420, which can be summed.
The summable supplies are designed so that they split the current supplied to the
load almost equally, which also has the added benefit of increasing total system
MTBF, and to distribute the thermal load across the backplane. Summable supplies
should be installed at opposite ends of in the Quantum backplane to maximize the
system thermal performance.
The Quantum system POK signal in systems powered by two summable power
supplies is only true (power is OK) when both internal POK signals (in the
140CPSX14X0) are true. Quantum summable power supplies are not hot-
swappable.
The following figure shows that the internal summable supply Quantum POKs are
ANDed to create the Quantum System POK.
The proper method for starting systems powered by summable power supplies is to
insert both supplies in the backplane in an unpowered state, and then apply power
to each supply. For 140CPS11410, 140CPS21400, and 140CPS414 models, there
is no requirement to power each supply simultaneously. For 140CPS11420, or
wherever this module is operated with a 140CPS11410, the delay between the two
powering times should not be greater than five seconds. The system designer must
realize that the operation of the summable supply described above is independent
of total backplane load, i.e., even if the total load on the backplane is less than 8 A,
if there are two summable supplies installed in the backplane, the system POK is
generated as shown in this section.
For the special case of a single summable supply used as a standalone, the system
POK generation reverts to the standalone case as shown previously in this section.
Redundant Power Supplies
Five redundant power supply models are offered:
• 140CPS12400 115 ... 230 Vac input 8 A output
• 140CPS12420 115 ... 230 Vac input 11 A output
• 140CPS22400 24 Vdc input 8 A output
• 140CPS42400 48 Vdc input 8 A output
• 140CPS52400 125 Vdc input 8 A output