APC VS 100 User Manual

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. 
 

 

 

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.