Nautel VX150 - Page 31

VX150 TO VX2 TROUBLESHOOTING MANUAL RESPONDING TO ALARMS
VERSION 2.0 2023-04-20 PAGE 3.1.23
Low Ac Foldback
The AC Voltage meter is less than 185 VAC
and the output power setpoint in the active
preset is greater than 750W.
The presence of this alarm will cause a
reduction in output power to 750W.
This alarm is only present in VX1.5 and VX2
models.
The AC voltage meter is greater than 185
VAC.
This alarm will also clear if RF is OFF or if the
output power setpoint in the active preset is
reduced to below 750W.
The most likely cause for this alarm is a
phase failure or brownout on the AC
supply to the transmitter.
Check the AC supply voltage at the
transmitter connection.
If the Transmitter has been intentionally
connected to a 120 VAC supply, then
reduce the setpoint below 750W.
Low Ac Shutback
The AC Voltage meter is less than 90 VAC.
The presence of this alarm will temporarily
inhibit RF operation until cleared.
This alarm will automatically clear when the
AC Voltage meter is greater than 90 VAC.
The most likely cause for this alarm is a
brownout or other failure on the AC
supply to the transmitter.
Check the AC supply voltage at the
transmitter connection.
Low Ambient Temperature
Warning
The Ambient Temperature meter is less than
0°C.
No action is taken on this alarm.
This alarm will automatically clear when the
Ambient Temperature meter is greater than
5°C.
Check site heating or ventilation system.
Allow transmitter to warm above 0°C
before operating.
Low Forward Power
The Forward Power meter measures a value
less than the Low Forward Power Threshold
(User-Adjustable, default: 50% of the active
preset output power setpoint) for at least 1
second.
No action is taken on this alarm.
This alarm will automatically clear when the
Forward Power meter value is greater than
the Low Forward Power Threshold for at least
1 second.
Check for other transmitter alarms, this
alarm serves as a general indicator
resulting from any substantial reduction
of Transmitter Forward Power.
Low RF Drive The RF Drive meter measures a value less than
the minimum expected drive level for the
given transmitter model when RF is ON and
uninhibited.
The RF Drive meter measures a value greater
than the minimum expected drive level for
the given transmitter model.
This alarm will automatically clear if RF is
turned OFF or RF is otherwise inhibited.
The most likely cause of this alarm is
either an IPA failure, an Exciter failure,
or a disconnection in-between.
Check the IPA connections, fuse, and
FET.
Check the signal level out of the Exciter
J10 using a spectrum analyzer or other RF
measurement device.
Alarm Name Trigger Conditions Clear Conditions Troubleshooting