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950-719-111-03, Revision 03
Installation and Test
PCS-719 List 1A
June 29, 2000
23
C
ONNECTIONS
Ground Connections
Two Frame Ground termination points are provided on the COT shelf. The J22 and TB1 FGND Frame Ground
termination points are electrically equivalent. To ground the COT shelf, do one of the following ground
connection options:
•
J22 Connection
The preferred termination point is at J22, located on the lower left corner of the COT shelf backplane.
This ground lug will accept wire in the range of 6 to 12 AWG.
1
Using a wire gauge of the same size as the common equipment frame ground wire, remove 5/8-inch of
insulation and insert the stripped wire into the ground lug J22.
2
Using a flat-head screwdriver, secure the wire in the lug.
3
Attach the other end to the common equipment frame ground using locally approved methods.
•
TB1 FGND Connection
The TB1 termination point is on the shelf backplane. A minimum of 12 AWG wire should be used for
this connection.
1
Using minimum 12 AWG wire, attach a spade lug connector to terminate the ground wire on the FGND
terminal of TB1.
2
Connect the other end of the frame ground wire to the CO Frame Ground termination point using locally
approved methods.
Power Connections
The TB1 termination point on the COT shelf backplane provides connections for dual –48 Vdc, common battery
return, and frame ground by way of screw terminals. The shelf can be wired for redundant powering,
split-powering, or single-source powering depending upon requirements. The following sections describe the
three powering options available on this device. The preferred powering method is the redundant shelf powering.
Prior to performing any power connections:
1
Remove all fuses in the equipment bay's fuse panel for the circuit(s) where the –48 Vdc power leads will be
terminated until the COT shelf is wired and ready for turn-up.
2
Run the battery and battery return lines from the fuse panel to the COT shelf using a minimum of 12 AWG
wire.
3
Connect to a reliably grounded –48 Vdc source that is electrically isolated from the AC source.
4
The –48 Vdc circuits should be fused according to
5
Disconnect both input supply sources before servicing.
Frame Ground must be connected to provide a discharge path for outside plant protection
circuits.
Use this connection only if the equipment frame has a common equipment ground wire running
along the vertical member of the frame.