Robinsons R66 - Troubleshooting

SEP 2012 R66 Maintenance Manual Chapter 21 Environment Control Page 21.9
21-24 Troubleshooting
1. If air exiting overhead duct is not cold:
POSSIBLE CAUSE TROUBLESHOOT/CORRECTIVE ACTION
Low Refrigerant
Charge/ Refrigerant
Leak
Recover refrigerant per Section 12-82. System should operate normally on
approximately 2.5 lb refrigerant.
If less than 2.5 refrigerant is recovered, perform leak detection per Section 12-83,
repair leaks if any, and charge system with refrigerant per Section 12-82.
Switch or Wiring
Problem Interrupting
Compressor Power
With aircraft not running, turn on Master switch and A/C switch on overhead duct
(low or high setting ok). Have observer listen to and observe compressor clutch
through cowl door. Clutch should engage (click and snap against pulley) whenever
A/C is switched on.
Check wiring at freeze switch (refer to Section 21-23), high and low pressure
switches (near compressor assembly), and full-down collective switch. Repair
any damaged wiring or connectors. Check continuity through each switch. All
switches should be closed with a properly charged system and aircraft at rest on
ground. Replace any defective switch.
Failed Compressor
V-Belt
Inspect belt.
Replace belt per Section 21-21 as required.
Insufficient
Condenser Airflow
Inspect condenser installation. Verify no blockage and all seals in place.
Remove blockage and/or repair seals to ensure airflow through core.
Extreme
Environmental
Conditions
Extreme temperature and humidity may result in cooling effect less than a typical
automobile.
No corrective action available.
2. If excessive condensation is found near evaporator assembly:
POSSIBLE CAUSE TROUBLESHOOT/CORRECTIVE ACTION
Blocked or Kinked
Evaporator Drain
Verify system is draining normally. After several minutes ground run in humid
conditions with A/C on, water should be seen draining from the drain tube.
If water drainage is not observed, inspect drain line (refer to Section 5-45). Correct
any damaged or kinked lines. Clean sediment trap as required. Verify proper
function of check ball.
Extreme Humidity Some condensation is unavoidable in extreme humidity.
Ensure all fresh air vents closed. Limit opening and closing cabin doors as much as
practical to limit humidity entering cabin.