Applicable Systems
VRV IV-S
Symptoms
The air conditioner reports an expansion valve opening anomaly. The EEV is not at the expected opening position.
Possible Causes
- EEV stepper motor missing steps
- EEV mechanism binding from contamination
- Control algorithm not commanding correct opening
Troubleshooting Steps
- Step 1: Check the EEV motor drive signal
Signal is clean and correct - Step 2: Inspect the EEV for mechanical binding
Valve moves freely - Step 3: Verify the control algorithm parameters
Parameters are correct for the operating condition
How to Reset
To reset: Repair the EEV, then clear the fault.
Source: Daikin Air Conditioner Service Manual, Daikin Industries Ltd.
Category: HVAC Residential