Nautel XR6, Troubleshooting Manual, Page: 32 / 291

XR6/XR3 Troubleshooting Manual Responding to alarms
Page 1-12 Issue 3.0 2009-07-15
3. If the transformer taps are correct, the monitoring circuit is suspect. Contact Nautel for
troubleshooting information.
Fan P/S fault
The 48 V power supply used for the fans is monitored and will report a fault if the voltage is outside
the range of 48 V ± 10%.
1. Check for accompanying alarms in the
Status
screen. If there is a
LVPS Fault
, troubleshoot it
first (see LVPS fault ).
2. Measure the voltage between R48-LHS and ground on the distribution PWB. If it is within
the range of 48 V ± 10%, recalibrate the 48 V supply to read the measured voltage (see
“Calibrating meters” on page 2-19 of the Operating and Maintenance Manual ). Otherwise
replace power supply U2.
RF drive P/S fault
The 62 V dc power supply used for the RF drive is monitored and will report a fault if the voltage is
outside the range of 62 V ± 10%.
The alarm could result from a fault in the RF drive power supply PWB, or faulty detection circuitry
on the RF drive power supply PWB. Troubleshoot an
RF Drive P/S Fault
alarm as follows.
1. Check for accompanying alarms in the
Status
screen. If there is a
LVPS Fault
or
Fan P/S
Fault
, troubleshoot it first (see LVPS fault or Fan P/S fault ).
2. Measure the voltage between R50-RHS and ground on the distribution PWB. If it is outside
the range of 62 V ± 10%, adjust the RF drive power supply PWB’s
VOLTAGE CONTROL
potentiometer R3 to restore the voltage within its acceptable range.
3. If the input voltages are satisfactory, and the output cannot be adjusted to the required level,
suspect the RF drive power supply PWB.
4. If the output voltage is within 62 V ± 10%, and the alarm persists, recalibrate the RF drive
power supply to read the measured voltage (see “Calibrating meters” on page 2-21 of the
Operating and Maintenance Manual ).
LVPS fault
The 24 V, 15 V, -15 V and 5 V power supplies are monitored and will report a fault if the voltage is
outside the range of ± 10%. One or more of these faults will result in only one
LVPS Fault
message
on the
Status
screen, though each one would be reported by the
Events Log
.