Midea Vrf V4 Plus Service Manual ((link)) -

Review — Midea VRF V4 Plus Service Manual

Summary

• The V4 Plus allows for long piping runs (up to 1000m total length depending on configuration), but this requires additional refrigerant.
• The manual contains the specific formula: Additional Refrigerant = (Length of Liquid Pipe x Factor) + ...
• If you skip this calculation found in the manual, the system will likely trip on low pressure or compressor overheating.

Sensor Calibration: Check thermistors against the resistance-temperature table found in the manual's appendix. midea vrf v4 plus service manual

| Error Code | Description | Manual Reference Page | Quick Diagnostic | | :--- | :--- | :--- | :--- | | E1 | High pressure protection | 4-22 | Check condenser coil cleanliness; HP sensor resistance. | | E3 | Low pressure protection | 4-24 | Refrigerant leak check; suction valve fully open? | | P0 | IPM module protection | 5-11 | Test DC bus voltage (310-350V). Check compressor wiring. | | EE | EEPROM parameter error | 3-08 | Replace main PCB; cannot be field-repaired. | | L5 | Outdoor fan motor | 5-32 | Common in V4 Plus; check DC fan motor Hall sensor. | | dL | Communication (indoor-outdoor) | 3-44 | Check shielded twisted pair wiring; end resistor (120Ω). | Review — Midea VRF V4 Plus Service Manual Summary

Oil Balance: The V4 Plus uses sophisticated oil return logic. Ensure the system is configured correctly if you're using multiple outdoor units in a combination. The V4 Plus allows for long piping runs

• Standard length: 5 meters (16.4 ft) – no additional charge needed below this.
• Pipe size correction: For Ø15.88mm liquid pipe, use 0.055 kg/m instead of 0.022.
• Indoor unit factors:

  2. Specifications & Dimensions

  Technicians must refer to this section for:

  Chapter 5: Emergency Operation & Bypass Modes

  When the main controller fails, the Midea VRF V4 Plus Service Manual provides two emergency protocols: