Nortel Networks 553-3001-211 manual Power requirements

Page 526 of 894 NT8D02 and NTDK16 Digital Line cards

Power requirements

The digital line card needs +15V DC over each loop at a maximum current of 80 mA. It requires +15V, -15V, and +5V from the backplane. The line feed interface can supply power to one loop of varying length up to 1070 m (3500 ft) using 24 AWG wire with a maximum allowable AC signal loss of

15.5dB at 256 kHz, and a maximum DC loop resistance of 210 ohms; 26 AWG wire is limited to 745 m (2450 ft).

Table 169

Digital line card—power required

Voltage	Current (max.)
±5.0 V dc	150 mA
+15.0 V dc	1.6 Amp
–15.0 V dc	1.3 Amp

Foreign and surge voltage protections

In-circuit protection against power line crosses or lightning is not provided on the NT8D02 Digital Line card. The NT8D02 Digital Line card does, however, have protection against accidental shorts to –52 V dc analog lines.

When the card is used to service off-premise telephones, primary and secondary Main Distribution Frame (MDF) protection must be installed.

Off-premise telephones served by cable pairs routed through the central office, or crossing a public right-of-way, can be subject to a requirement for on-card protection, and MDF protectors may not be acceptable. Check local regulations before providing such service.

553-3001-211 Standard 2.00 September 2004