User's Manual
3. Ground the Negative side of the Hub Transceiver DC cable to the OJB common ground
bus.
4. Ground the shields of all DC and IF cables to the OJB common ground bus.
5. If there is any doubt about the continuity of structural ground between the OJB
grounding point and the equipment room electrode, run a properly terminated (minimum)
#6 copper cable from the OJB common ground bus to the ground bus bar in the
equipment room.
6. Route the IF, DC power cable and ground cable from the OJB to the base station
equipment room. Utilize appropriate mounting hardware and/or UV-rated tie-wraps.
6.3 Other Suppliers’ Outdoor Equipment
1. Backhaul microwave antennas, etc. are to be mounted on the supporting structure per
the recommendations of the manufacturer. All requirements for attachment, grounding,
connector weatherproofing, etc. are to be carefully observed.
2. Route all cables and/or waveguide from the outdoor equipment(s) to the base station
equipment room. Utilize appropriate mounting hardware and/or UV-rated tie-wraps.
6.4 Equipment Room Installation – Cable Entrance and Grounding
1. Mount a ground bus bar adjacent to the cable entrance to the equipment room structure.
a. Connect the ground bus bar to the ground electrode with a properly terminated
(minimum) #6 copper cable [or copper ground strap of equivalent cross-sectional
area] as described in the National Electric Code sections 820-33, 820-40 and
820-41. A common technique is to route the (minimum) #6 copper cable to a
driven ground rod adjacent to the point of entry of the coax cable to the building
containing the equipment room, and thence to the building electrical service
ground point per NEC 820-40. It the Hub Transceivers are mounded on a
metallic tower structure adjacent to the equipment room a similar properly
terminated (minimum) #6 copper cable should also be run from the electrode to
the tower steel. All grounding to conform to local codes.
b. Connect the ground bus bar to the indoor equipment rack with appropriate
copper strap or (minimum) #6 copper cable.
c. Note that ground wires employed for lightning protection must NEVER be routed
in metallic
conduit, pipe, EMT, etc. If lightning ground wires are enclosed they
must be routed through non-metallic
tubing such as PVC.
2. Mount a suitable lightning protector (e.g. PolyPhaser Model IS-75F-C1) to the ground
bus bar for each IF coaxial cable between an Hub Transceiver and the equipment room.
3. Mount a suitable lightning protector (e.g. PolyPhaser Model IS-17VDC-30A-NG) to the
ground buss bar to protect the DC power supply.
4. Mount a suitable lightning protector to the ground bus to protect any other cable and/or
waveguide routed between the antenna mounting structure and the equipment room.
5. Connect all shields associated with any wiring entering or leaving the equipment room to
the ground bus bar.
6. Ensure that all coax cables and DC power cables are properly terminated and connected
to the “antenna” or “surge” side of each lightning protector.
7. Note that the “equipment” or “protected” side of each lightning protector is a convenient
and appropriate point to demarcate the outside
portion of the installation as specified
above, and the inside
installation which will be specified following.
June 2003 Page 6-2