NEC NEAX2000 ND-91649, General Description Manual

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ND-91649(E) CHAPTER 4
Page 39
OVERVIEW OF INSTALLATION, PROGRAMMING, AND MAINTENANCE
CHAPTER 4 OVERVIEW OF INSTALLATION, PROGRAMMING, AND
MAINTENANCE
Installation
Items to be Provided at Site
The following items are required for correct operation.
a.) Adequate space accommodation
b.) Adequate ventilation
c.) Commercial
AC power
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 ohm
Protective ground for PIM : Less than 10 ohm
Note:
The AC ripple on these various grounds should be less than 0.5Vp-p.
The following specific requirements apply to ground wiring.
An equipment-grounding conductor that is at least as large as the ungrounded branch-supply conductors is to be
installed as part of the circuit that supplies the PBX. Bare, covered, or insulated grounding conductors are
acceptable. Individually covered or insulated equipment grounding conductors shall have a continuous outer
finish that is either green, or green with one or more yellow stripes. The equipment grounding connector is to be
connected to ground at the service equipment.
The attachment-plug receptacles in the vicinity of 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.