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Rockwell Automation Publication 1753-IN001C-EN-P - June 2010
Controller Tests
In addition to the tests for safety, the controller tests the supply voltage and controller
temperature.
Supply Voltage Tests
The supply voltage (24V DC) is monitored and the alarm and system shutdown are controlled
according to the voltage levels listed below.
Temperature Tests
The temperature of the controller is automatically and continuously monitored. The alarm is
triggered by the temperature conditions described in this table.
Voltage Level
System Condition
19.3…28.8V Normal
< 19.3V
Alarm state 1 (internal variables are written)
< 15.4V
Alarm state 2 (prepares for shutdown)
< 13.0V
Switched off
Operating Temperature
Alarm
< 60 °C (140 °F)
None (normal)
60…70 °C (140…158 °F)
Warning on
> 70 °C (158 °F)
Main alarm on
Return to 64…54 °C (147.2…129.2 °F)
Main alarm off, warning on
Return to < 54 °C (129.2 °F)
None (return to normal)
