Nortel Networks 400 4.0 Electrical requirements, Site telephony wiring requirements, Digital loop

88Chapter 5 Checking the installation prerequisites

Electrical requirements

Ensure you meet the following electrical requirements:

•Power must be supplied from a non-switched, unobstructed outlet within 1.5 m (5 ft.) of the BCM units.

•The supplied power must be 100/240 V AC, 50/60 Hz, and 10 A minimum service with a third-wire safety ground. The third-wire safety ground provides shock protection and prevents electromagnetic interference.

Danger: Risk of electric shock

The safety of this product requires connection to an outlet with a third-wire ground. Use only with the supplied BCM power supply and a three-wire power outlet.

Caution: Check ground connections

Ensure that the electrical ground connections of the power utility, telephone lines, and internal metal water pipe system, if present, are connected together. If these ground connections are not connected together, contact the appropriate electrical inspection authority. Do not try to make the connections yourself.

•You can connect the power supply to a power bar. The total length of the power cables from the power supply to the electrical outlet (including power bar) should not exceed 2 m (6.5 ft.). You must use a power bar approved by an appropriate National Test Body, with a third-wire ground. Nortel recommends not to use an extension cord between the power supply and the power bar, or between the power bar and the electrical outlet.

Site telephony wiring requirements

This section describes the requirements for wiring digital telephony devices (digital loop) and analog telephony devices (analog loop) to the BCM system.

Refer to the following sections for information on the parameters for digital and analog loops:

•“Digital loop”

•“Analog loop” on page 89

Digital loop

The following parameters must be met for a digital loop:

•one, two, or three twisted-pair cables per telephone

•DC loop resistance of less than 64

•cable length (0.5 mm or 24 AWG) less than 300 m (975 ft.)

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