Thermo King SR-2 SmartReefer2, Diagnostic Manual

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Section 5 – SR-2 Diagnostics
84 RESTART NULL
Page 1 of 1
Alarm Type Prevent Alarm
Associated Alarm
Codes Alarm Codes 10, 17, 18. 20, 21, 22, 36, 63, 90 and 91
How Alarm is Set
This alarm is set with the associated alarm that caused the condition.
How Alarm is Cleared
This alarm clears automatically if the condition is resolved.
Considerations
1. This alarm is a secondary alarm that is set along with the associated primary alarm.
2. The alarm indicates that the unit is in a temporary (“prevent” or “restart null”) shutdown. The alarm clears
automatically if the condition does not re-occur.
3. Many of these actions include a “waiting period” (to allow the engine to cool down, a high pressure
condition to subside or the like). The alarm code that caused the condition and Alarm Code 84 might be
present to indicate that the microprocessor is taking a corrective action and that a restart will be attempted
when conditions permit.
4. If the corrective action is successful, the original alarm code, as well as Alarm Code 84, are cleared
automatically. If the original alarm condition continues to occur, and the corrective actions taken by the
microprocessor are not successful, the original alarm code remains. Alarm Code 84 is automatically
cleared and the unit shuts down.
5. This alarm occurs if unit operation is prevented, as a result of the associated prevent alarm. For example, if
a high discharge pressure condition shuts the unit down, a waiting period occurs to allow system pressures
to equalize. A restart occurs when conditions permit.
6. If restarts are disabled Alarm Code 84 is also disabled.
7. Most prevent alarms become shutdown alarm if three occurrences of the alarm occur within a set time
period.
8. Alarm Codes 10, 18 and 63), are not promoted to shutdown level if the Continuous Restarts feature is
enabled.
Diagnostic Procedure
Check for associated alarms and repair as required.
5-64
02 February 2005