4
Power Connection
4.3
Fig. 4.2.
Power source connections
To connect the Site Controller SCM to a power source, follow these steps:
NOTE:
Do not apply –48V Power to the Site Controller SCM until all power Connections in Step 1
through Step 7 have been completed.
NOTE:
Use proper lug terminations on all power and frame ground connections to the Site Controller
SCM power input terminal strips.
NOTE:
The "A" and "B" power leads must be diversely run from the power input terminal strips to their
power source. One power lead must be routed on one side of the bay and the other routed on the
other side of the bay.
1. Remove the fuse from the front panel of the Site Controller SCM and make sure that the power supply to the
unit is off.
2. Remove the screw lug barrier plug from the front panel of the Site Controller SCM.
3. Connect a –48 VDC line to the –48V terminal and a battery ground to the GND terminal of the screw lug.
Seat the barrier screws firmly, but be careful not to nick the bare wire. Repeat for power source B if you have
dual power inputs.
4. Push the plug firmly back into its socket. Note that this connection is keyed and the plug must be properly
aligned within the socket.
5. For earth/frame grounding, connect a copper wire with a ring terminal to the grounding post located on the
back panel of the Site Controller SCM. DPS Telecom recommends wire of at least 14 gauge. Place the ring
terminal between the two nuts and secure the nuts on the grounding post. Connect the other end of the wire to
an earth/frame ground.
6. With the Site Controller SCM fuse still removed, turn on the power supply.
7. Connect the black common lead of a voltmeter to the GND terminal and the red lead to the –48V terminal.
The voltmeter should read between –43 and –53 VDC. If the reading is outside this range, check your power
supply.
8. Do not power the unit until all connections have been made.
9. Insert the fuse to power the Site Controller SCM.
