Installation Manual

34 Installing Backup Power
Inserting Tandem PSUs into a Rack
To install two PSUs in tandem (side-by-side) in a rack, follow these steps:
Connecting the DC-to-DC Cable
The PSU kit includes two power cables — the cable that connects the PSU to the AC source and the
DC-DC cable that connects the PSU to the terminal block on the back of the S25V. The DC-DC cable
length is 1 meter (3 feet), with a keyed plug connector at one end that connects to the PSU, and, at the other
end, individual wires that connect to the DC terminal leads in the rear of the S25V.
Step Task
1.
Using a #2 Phillips screwdriver, attach the supplied extended rack ears to the outside, front sides of
the two PSUs. As shown in
Figure 20, the long side of the rack ear is attached to the PSU, with the
short side projecting at right angles away from the front corner of the PSU.
2.
Join the two units with the supplied twinning plate (the small, flat, I-beam-shaped metal adapter with
four screw holes), using two screws on each side of the plate through the front inside corners of the
two switches. Orient the adapter with the cross-bars of the I-beam horizontally, so that the fan and
power LEDs in the left-hand PSU are not obscured.
Figure 19 Twinning Plate Oriented over Two PSUs
3.
As shown on the left side of Figure 20, attach the rack ears to the rack with the supplied screws or
cage nuts, depending on the style of your rack.
Figure 20 Two PSUs Mounted Side-by-Side
Power
Fan