Network Card User Manual

Cisco AS5800 Product Overview 1-25
Dial Shelf DC-Input Power Supply
• System environmental monitoring
A 10-pin connector monitors system environmental status and communicates this status from
each PEM to the filter module maintenance bus (MBus). Table 1-6 lists connector pins
supporting system status signals.
• Voltage level and current monitoring
The DC-input power supply is designed to prevent any energy hazard during operation. DC
power is first routed to a circuit breaker, followed by a surge protector. In addition, an isolation
diode circuit protects against possible DC-input failure.
The DC-input power supply monitors analog output voltage and current. The battery side of the
DC input is equipped with a 60 A circuit breaker, which trips if current reaches peak parameters
for 2 sec. The DC-input power supply circuits are described in Table 1-7.
If a PEM is not properly seated in the Cisco 5814 dial shelf backplane, an electronic circuit, or
interlock, trips a breaker in the PEM and terminates power to the output connectors. This same
interlock provides reverse polarity protection when the system is powered off.
Note Connect the alarm port only to a safety extra-low voltage (SELV) source using 22 AWG, or
thicker, copper wire. SELV ratings are maximum 30 Volts AC (RMS), maximum 60 Volts DC, and
maximum 50 VA Power. The alarm port is rated for 2.0 Amp maximum current.
Table 1-6 Connector Pin Definitions
Pin Description Pin Description
1 –48V monitor 6 Not used
2 Not used 7 Not used
3 Breaker connect 8 –48V return monitor
4 Current monitor 9 Not used
5 Voltage monitor 10 15V_BIAS
Table 1-7 DC-input Power Supply Circuits
Circuit Description
Circuit breaker PEM output is enabled when this pin is shorted to the -48Vmonitor pin by
way of the backplane. If the connection is broken, the breaker is tripped
and cannot be reset until the PEM is reinstalled.
Reverse polarity An electronic interlock that provides reverse polarity protection.
Current monitor Analog output voltage is proportional to DC-output current from the PEM
to the backplane, as follows: 1 A of current is equivalent to 100 mV at the
current monitor pin.
Voltage monitor Analog output voltage is proportional to DC-output current from the PEM
to the backplane, as follows: 1 A of current is equivalent to 100 mV at the
voltage monitor pin.
Bell alarm A terminal block for connecting to central office alarms (C, NC, NO)