Nautel NX15, Руководство по устранению неисправностей

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NX25/NX15 Troubleshooting Manual Responding to alarms
Page 1-22 Issue 5.0 2016-05-06
Exciter A/B: Over
Current Shutback This alarm indicates the peak RF current at the output of the
transmitter has exceeded the Peak RF Current Limit. This alarm
causes the transmitter to immediately shut down its RF output and
then recover. If this alarm occurs in conjunction with the
Controller’s Fast SWR Shutback alarm, there may be a fault in the
transmitter’s external RF output network (i.e, rigid-line, antenna,
etc.). If this alarm is occurring without the presence of the
Controller’s Fast SWR Shutback alarm, verify the RF current
sample, RF voltage sample and the wiring between the sample
point and the control/interface PWB is not damaged. If the
alarm
persists, replace the associated digital AM exciter PWB (see
“Digital AM exciter PWB replacement” on page 1-55 ).
Exciter A/B: PLL
Unlocked This alarm indicates the exciter's phase lock loop, which locks the
transmitter's carrier frequency to a 10 MHz reference, is no longer
locked to the reference. If an external 10 MHz source is being
used, the exciter will fall back to using its internal 10 MHz clock.
Otherwise, the exciter will inhibit its output. If an external 10 MHz
source is being used, check the integrity and signal level of the
source. If the alarm persists, replace the associated digital AM
exciter PWB
(see “Digital AM exciter PWB replacement” on
page 1-55 ).
Exciter A/B: Power
Below Setpoint This alarm indicates that the transmitter cannot achieve the
desired output power. For the alarm to occur, the power must be
at least 10% below the setpoint for more than four (4) seconds,
and the exciter is not able to increase the output power because it
has reached maximum gain, or the output is being limited by a
foldback condition. The alarm is typically accompanied by other
alarms. See the troubleshooting action for the associated alarms.
Exciter A/B:
Precorrection Inhibited This alarm indicates that the exciter has disabled its pre-correction
compensation. This alarm will occur because the transmitter’s B+
voltage is too low. See the troubleshooting action for the
associated low B+ voltage alarm.
Exciter A/B: Protection
Mechanisms Disabled This alarm indicates that the exciter’s protection (shutback,
foldback, cutback) has been turned off by the user. The state
should only be required when calibrating the transmitter after a
frequency change. If this state is not intentional, press the reset
button on the associated digital AM exciter PWB. If the alarm
persists, replace the associated digital AM exciter PWB
(see
“Digital AM exciter PWB replacement” on page 1-55 ).
Alarm (with Prefix) Description and Troubleshooting Action