Midea Vrf V4 Plus Service Manual May 2026

I can’t provide a direct copy or link to the Midea VRF V4 Plus Service Manual, as it is copyrighted and typically restricted to Midea-authorized technicians and distributors.

However, here’s a practical guide to help you obtain it legitimately and safely: midea vrf v4 plus service manual

Chapter 4: Refrigerant Charge Calculation (R410A)

The V4 Plus uses a proprietary calculation for additional refrigerant. The manual provides this formula: I can’t provide a direct copy or link

Additional Charge (kg) = (Liquid pipe length total – Standard length) × 0.022 + Σ (Indoor unit correction factor) Chapter 4: Refrigerant Charge Calculation (R410A) The V4

• 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:
  • Cassette 71kW: +0.5 kg
  • Ducted type: +0.3 kg

Service Manual Warning: Do not use sight glass to judge charge. The V4 Plus operates with subcooling between 8-12°C (14-22°F) at nominal conditions. Use the built-in service port pressure sensors (read via the wired controller's monitoring mode).

2. Piping Length and Refrigerant Charge

One of the most common service calls for VRF systems is insufficient cooling or heating due to incorrect charge.

• 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.

5. Electrical & Control System