Nautel NX15, Troubleshooting Manual

Page: 38 / 274

NX25/NX15 Troubleshooting Manual Responding to alarms
Page 1-30 Issue 5.0 2016-05-06
Rack #: Arc Detector 1 This alarm indicates that the transmitter’s arc detector has
detected an arc and caused the transmitter to shut back. Due to
the sensitivity of the arc detector, it is possible for an external UV
source to cause this alarm. Check and remove all external UV
sources. If the alarm persists, perform a visual inspection inside
the rear of the transmitter for signs of corona or arcing.
Rack #: EEPROM
Failure This alarm indicates that the rack controller has failed to load its
configuration from EEPROM. Remove and reapply the ac power
to the transmitter. If the alarm persists, replace the rack interface
PWB (see
“Rack Interface PWB replacement” on page 1-64 ).
Rack #: High AC Voltage This alarm indicates the rack interface’s Ac Sample meter is
above 384 V. The alarm clears when the sample falls below this
voltage. It can be caused by an improperly tapped power
transformer or a transient on the ac mains. Verify the mains
transformer is tapped correctly (see
“Installing the power
transformer” on page 3-1 in the Installation Manual). If so, monitor
the ac mains for transient conditions when this alarm occurs.
Rack #: High B+
Shutback This alarm occurs when the B+ voltage measured by the rack
interface exceeds the set threshold (normally 430 V). This causes
the transmitter to disable the B+ power supply until the B+ voltage
has decreased an additional 15 volts below the threshold. This
alarm normally occurs with extreme changes in transmitter power
(i.e., preset changes, interlock open, etc.). If the alarm is occurring
continuously, or when unexpected, monitor the B+ with an
oscilloscope and determine if the B+ is exceeding the shutback
limit. If it is not exceeding the limit, verify the ac mains transformer
is tapped correctly (see
“Installing the power transformer” on
page 3-1 in the Installation Manual).
Alarm (with Prefix) Description and Troubleshooting Action