CHAPTER 2 INSTALLATION
– 62 –
NWA-008841-001 Rev.5.0
90ch2001.fm
PRECAUTIONS
Grounding Requirements
The system grounding must have a specific ground resistance and AC noise level, and is to be connected
to a predetermined terminal in the PBX. Standard grounding requirements are as shown below:
• Communication grounding: Less than 10
Ω
• Protective ground for PIM : Less than 10
Ω
NOTE:
The AC ripple on these various grounds should be less than 1/2 Vp-p.
The following specific requirements apply to ground wiring.
Install an equipment grounding conductor that is at least the same size as the ungrounded branch-
supply conductors as part of the circuit that supplies the PBX. The main grounding conductor shall
be green with one or more yellow stripes. Or the equipment grounding conductors shall have a
continuous outer finish that is green. The equipment grounding connector is to be connected to
ground at the service equipment. For details of wiring connections, see
“WIRING POWER CABLE
TO TERMINALS”
.
Page 76
The attachment-plug receptacles near the PBX are all to be of a grounding type, and the equipment
grounding conductors serving these receptacles are to be connected to earth ground at the service
equipment.
CAUTION
Grounding circuit continuity is vital for safe operation of telecommunication equipment.
Never operate this equipment with the grounding conductor disconnected.
OCTOBER/19/2006
PRECAUTIONS