APC VS 50 Power Supply User Manual


 
Magnum VS –48 Vdc User’s Manual Page 9
3.5. Counter Electro-Motive Force (CEMF) Cell Connections
WARNING: Hazardous energy levels are present on the CEMF connection
area of the plant. Accidental shorting of conductors can cause arcing and
high currents that can cause serious burns or other physical harm.
In some applications, a CEMF cell is used to lower the dc voltage delivered to the loads. The
CEMF cell is mounted externally to the Magnum VS. The CEMF connections are located at the
rear of the unit as shown in Figure 3.5-1. Two bus-plates, installed at the factory, bypass the
CEMF connection. If a CEMF cell will be used, remove the bus plate connecting the two CEMF
connection points and install two connection buses before installing the CEMF. The CEMF
connection buses each provide a pair of #10-32 studs on 5/8” centers for connecting two-hole
CEMF cable lugs. A ring size of 6 mm may also be used. Connect the CEMF cables as
applicable using #10-32 nuts.
Figure 3.5-1 CEMF Connection Locations
3.6. DC System Grounding
The positive bus for the power plant should be connected to the Central Office Ground. The
Battery Return provide a pair of #10-32 studs on 5/8-inch centers for connection of a two-hole
lugged cable to the Central Office Ground. A ring size of 6 mm may also be used. Cover this
connection with heat shrink tubing after assembly.
CEMF Connections