Magnum VS –48 Vdc User’s Manual Page 5
Ventilation
The rectifier modules for this system have fans that provide front-to-rear airflow for internal
cooling. The power system housing should be mounted such that there is free airflow to the
front and back of the unit. [Refer to Section 9.5 for environmental characteristics.] Free airflow
should be ensured so that the power system can provide full power without de-rating.
3.3. AC Power Connections
WARNING: Ensure that all of the external dc and ac circuit breakers are in the
OFF position prior to connecting service to the power plant. Confirm that all
voltages have been removed including any battery sources before proceeding.
AC Connections
The dc power system requires the supply of 85 – 264 Vac, 47 – 63 Hz single phase power. One
alternating current (ac) input on the power system backplane supplies power to the first rectifier
in each shelf. Two inputs supply power to the second and third pair of rectifiers and the fourth
and fifth pair in each shelf. This scheme allows a variety of wiring options. Provided the input
wiring is not overloaded, one, two or all three inputs on each shelf can be jumpered together.
The ambient temperature and number of wires in a conduit must be considered in accordance
with NEC and local requirements. The power system typically ships with the jumpers shown in
the backplane layout of the Magnum VS 50 shown in Figure 3.3-1. The Magnum VS 100
contains two identical backplanes. The input terminals are defined in Figure 3.3-3. If one ac
input cable is used it is typically connected to TRM10, 7 and 4.
Figure 3.3-1 Magnum VS 50 Backplane