NEC ND-91649 Overview Of Installation, Programming, And Maintenance, Items to be Provided at Site

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.

CAUTION

Grounding circuit continuity is vital for safe operation of telecommunication equipment. Never operate this equipment with the grounding conductor disconnected.

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.

ND-91649(E)	CHAPTER 4
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