User's Manual

044-05117
4-7 Amplifier Alarms
Causes for MCPA alarms are given in Table 4-1. Conditions external to the amplifier should be
investigated before replacing the amplifier, particularly if more than one amplifier exhibits a critical
alarm. Alarm conditions are reported to the amplifier subrack via RS-485 or TTL interfaces. Other
than the front panel LEDs (described in chapter 3), there are no other visual aids for the
technician.
Table 4-1. G3L-850-135 Alarm States
Major Alarm - Causes MCPA RF section to be
disabled
Minor Alarm - Does not cause MCPA RF section
to be disabled
Amplifier
Alarm
Definition
Amplifier
Mode
Auto-Recovery
Event/Fault Log
Output
Overpower
Disable the MCPA
immediately if the output
power is >2 dB over rated
power.
Major
No auto recovery. Requires
manual reset. Output power
must be decreased to < 2
dB over rated power.
Records output
overpower event after
system disabled
Automatic
Power
Control
(APC)
Enabled if the output
power is > 50 dBm
Note: If the MCPA cannot
compensate the gain to maintain
compliance, the Output
Overpower or Input Overdrive
Faults will protect the MCPA.
Minor
(Yellow
LED
display)
Amplifier auto-recovers
when the output power
drops below the rated
maximum output power.
Records APC event and
auto-recovery event if
auto-recovery
successful
Input
Overdrive
Disable the MCPA
immediately if the input
RF power is > -6.0 dBm
Major
No auto recovery. Requires
manual reset. Input power
must be decreased to < -6.6
dBm.
Records input overdrive
event, system disable
event, each auto
recovery event*
High
Temperature
Sensor temperature is >
+88° C
Major
Amplifier auto-recovers
when the sensor
temperature drops to < +73°
C.
Records over
temperature event,
system disable event,
each auto recovery
event,
Reflected
Power
Reverse RF output power
is > +47.8 dBm for a
duration of 1-minute
Major
No auto-recovery. Requires
manual reset. Reverse
power must be < 50% of the
maximum rated forward
output power.
Records high reflected
power event, each auto
recovery event*
High
Voltage
Disable the MCPA
immediately if the supply
DC voltage > +30.5 Vdc
Major
Auto-recovery when the
supply voltage drops to <
+30.0 Vdc
Records supply DC fault
event, system disable
event, each auto
recovery event*
Low
Voltage
Disable the MCPA
immediately if the supply
DC voltage < +20.5 Vdc
Major
Auto-recovery when the
supply voltage increases to
> +24 Vdc
Records low voltage
event, system disable
event, each auto
recovery event*
4-4 Installation and Service Manual - G3L-850-135 Multi-Carrier Power Amplifier