Nortel Circuit Card, Installation Manual, Page: 167 / 908

NT1R20 Off-Premise Station Analog Line card Page 167 of 906
Circuit Card Description and Installation
Power requirements
Table 65 shows the maximum power consumed by the card from each system
power supply.
Foreign and surge voltage protection
The NT1R20 OPS analog line card meets UL-1489 and CS03 over-voltage
(power cross) specifications and FCC Part 68 requirements for hazardous and
surge voltage limits.
Ringer limitations
The OPS line card supports up to three NE-C4A (3 REN) ringers on each line
for either ONS or OPS applications. See Table 66.
Table 65
OPS analog line card – power requirements
Voltage Tolerance Current (max.)
±15.0 V dc ± 5% 150 mA
+8.5 V dc ± 2% 200 mA
+5.0 V dc ± 5% 100 mA
–48.0 V dc ± 5% 350 mA
Table 66
OPS analog line card – ringer limitations (Part 1 of 2)
ONS Loop Range
Maximum Number of
Ringers (REN)
0–10 ohms 3
> 10–460 ohms 2