Nortel Networks Option 11C User Manual
Power supplies
Page 201 of 544
Over-voltage
An OVP (Over-Voltage Protection) circuit will shut down the power supply
if the output voltage exceeds the limits given in Table 62.
if the output voltage exceeds the limits given in Table 62.
All outputs in a shutdown state are reset by the SSC card.
The system power will not automatically reset when there is overvoltage on
the -52V DC output. Manual intervention is required. The manual int button
is located on the faceplate of the SSC card.
the -52V DC output. Manual intervention is required. The manual int button
is located on the faceplate of the SSC card.
Temperature sensor
The power supplies are sensitive to the temperature of the cabinet and the
system power. A thermostat is located at the top of the power supply unit. The
AC or DC input breaker will be tripped for temperatures higher than 80°C
(176°F).
system power. A thermostat is located at the top of the power supply unit. The
AC or DC input breaker will be tripped for temperatures higher than 80°C
(176°F).
Reserve power LED
The NTAK04 and NTDK78 AC/DC power supplies oversee the status of the
reserve power system. When the breaker on the NTAK28, NTAK75, or
NTAK76 breaker assembly trips, the “Batt” LED on the NTAK04 or
NTDK78 faceplate is turned off.
reserve power system. When the breaker on the NTAK28, NTAK75, or
NTAK76 breaker assembly trips, the “Batt” LED on the NTAK04 or
NTDK78 faceplate is turned off.
Table 62
Nominal and over-voltage limits of NTAK04, NTAK05, NTDK72 and NTDK78 power supplies
Nominal and over-voltage limits of NTAK04, NTAK05, NTDK72 and NTDK78 power supplies
Nominal voltage
Overvoltage limit
Power supply status
+5.1V
+6.4V
Complete Shutdown
+8.5V
+10.6V
Complete Shutdown
-150V
-187.5V
Complete Shutdown
+15V
+18.7V
Complete Shutdown
-15V
-18.7V
Complete Shutdown
-48V
N/A
N/A
Ring (Pk V)
150V
Complete Shutdown
-52V
-58V
Complete Shutdown