System Shutdown; Shutdown Conditions; Resetting Shutdown Faults - Pacific 110ACX Operation Manual

4.5

SYSTEM SHUTDOWN

This paragraph describes the conditions which will cause an automatic system shutdown and the
procedure used to reset the ACX-Series Power Source.

4.5.1 SHUTDOWN CONDITIONS

The Output Contactor of the ACX-Series Power Source will be opened automatically when:
1. Excessive temperature is detected. Either the input power circuit or one of the power
amplifiers has become too hot. Over-temperature is usually caused by either an overload
on the system output or restricted air-flow (air inlets may be blocked, dirty fan filters, or a
clogged or non-functioning fan).
2. The Output FORM (UPC controller) has been changed. While the Output Contactor is
engaged, any change of FORM, low range to high range or high range to low range, will
force the unit to open the output contactor so that the range can be changed safely.
When the Output Contactor has been opened due to one of the above faults, the red
SHUTDOWN LED on the front panel of the power source will be lighted. The output contactor will
remain open while the SHUTDOWN LED is lighted. This LED will remain lighted until the unit is
reset.
If the Output Power Switch is in the ON/AUTO position when the unit is turned on, the
SHUTDOWN LED will light. This is normal operation. The LED is turned off simply by placing the
Output Power Switch into the OFF position.

4.5.2 RESETTING SHUTDOWN FAULTS

A shutdown fault is reset as follows:
1. Set the OUTPUT POWER Switch to the OFF position.
If the unit is controlled through the remote (GPIB or RS-232) port, command the output
OFF (:OUTP OFF).
2. Wait for the SHUTDOWN LED to extinguish. This LED will remain lighted until the
condition which caused the shutdown to occur has been corrected. In the case of
shutdown due to over-temperature this may take some time while the unit cools. The
output contactor cannot be engaged until the shutdown fault has been cleared.
3. After the SHUTDOWN LED has been extinguished, the unit will function normally.
NOTE: The SHUTDOWN LED is latched ON when a fault occurs. The OUTPUT
POWER Switch or the Output Enable of the UPC MUST be placed in the OFF
position before the SHUTDOWN LED will extinguish, even if the original fault no
longer exists.
31
SECTION 4 OPERATION