MDF connections to stations and the public switched telephone network
58 Installing and Connecting the MDF and Telephones
The coupled bonding conductor (CBC) provides a path to ground for transient energy (for
instance, lightning) by virtue of mutual inductance between itself and exposed telcom cables.
The CBC connects on one end to an approved single-point ground, runs adjacent to the telcom
cable, and connects on the other end to the CBC terminal bar at the main distribution frame
(MDF).
The CBC can be:
●a 10 AWG (#25) (6 mm2) wire tie wrapped to the exposed telecom cables
●a metal cable shield around the exposed cables, or
●six spare pairs form the exposed cable
A minimum of 12" spacing should be maintained between the CBC and other power, ground, or
non-exposed communications cables.
Installing coupled bonding conductor wires
To install coupled bonding conductor wires:
1. At the DC power cabinet, connect a 10 AWG (#25) (6 mm2) ground wire to the Ground
Discharge Bar. See Figure27: Typical power and ground for a DC power cabineton
page 59.
2. Route the 10 AWG (#25) (6 mm2) ground wire to the CBC ground terminal bar at the MDF.
3. Tie wrap the ground wire to the inside wiring cable.