Engine Load Calibration
engine
Description
At start, after start, or at shutoff, the rack position sensor did not meet the 90% or 10% timing conditions, and the unit alarms only.
Activation Conditions
Activate alarm if: Condition 1 = At engine start if the engine throttle sensor (Rack Position Sensor) value is less than 90%. Condition 2 = After start if the sensor value does not drop below 90% within five seconds. Condition 3 = At engine shutoff if the sensor value does not drop below 10% within five seconds.
Unit Behavior
Alarm only. Control system will modulate CSMV and activate Economizer Control as required.
Reset Conditions
Alarm may be manually reset using the display mounted keys or by turning the unit off, then back on again.
Corrective Actions
1. Check Rack Position Sensor (RPS) Power And Wiring a. Inspect sensor, connector pins and terminals. Verify no physical damage to sensor. Check for damage or corrosion in connections. b. If required, power sensor by placing the unit in PC mode. Check for power. Voltage reading between connector position 1 (positive) and position 2 (negative) should be 5 volts DC. Check connectors and wiring between terminals for damage, moisture or corrosion. c. Check for continuity from connector terminal 3 to ENCU-7. If good continuity is not present, check connectors and wiring between terminals for damage, moisture or corrosion. 2. Perform the Engine Load Calibration - Refer to Section 8.6.13. 3. Replace Rack Position Sensor - Replace sensor with known good component. Calibrate sensor and ENCU. Refer to Section 8.6.13.