Midea MDV-335(12)W/D2DN1(B) - User Manual

Midea Commercial Air Conditioner
R410A All DC Inverter VRF V4 Plus S Series
220V~60Hz
Technical Service Manual

Midea MDV-335(12)W/D2DN1(B) Specifications

General

Brand	Midea
Model	MDV-335(12)W/D2DN1(B)
Category	Air Conditioner
Language	English

Summary

5. Wiring diagram and field wiring

5.1 Wiring diagram

Electrical wiring schematics for system components.

5.2 Field wiring

Part 4 Installation

1. Units installation

Procedures and guidelines for installing indoor and outdoor units.

3. Refrigerant piping selection

Guidelines for selecting refrigerant pipe sizes and lengths.

4. Refrigerant pipe installation

Detailed steps for installing refrigerant piping.

5. Drainage pipe engineering

11. Vacuum Drying

11.1 Purpose and main points of vacuum drying

Importance and critical aspects of vacuum drying the system.

11.2 Operation procedure

12. Additional refrigerant charge

12.1 Operation procedure for recharging refrigerant

Steps to calculate and recharge refrigerant.

12.2 Calculating the refrigerant recharge volume

Formula and table for calculating additional refrigerant.

13. Electrical wiring installation

13.1 Wiring terminal instruction

13.3 Electrical wiring installation

Notes and general guidelines for electrical wiring.

13.4 Control system installation

14. Running test

14.1 Inspection and confirmation before commissioning

Pre-commissioning checks for refrigeration piping and wiring.

14.2 Preparation before debugging

14.3 Commissioning of Trial Run

Procedures for trial runs of single and multiple outdoor units.

14.5 Refrigerant leakage caution

Safety precautions regarding refrigerant leakage and critical thickness.

Part 5 Troubleshooting

1. Outdoor main control board instructions

2. Error code table

A comprehensive list of error codes and their meanings.

3. Troubleshooting

General troubleshooting procedures for system issues.

4.1 E0: Communication error between outdoor units

4.2 E2: Communication error between indoor units and the master unit

4.3 E4: Malfunction of outdoor ambient temperature sensor (T4)

4.4 E7: Malfunction of discharge temperature sensor

4.5 E5: Malfunction of power supply voltage

4.6 E8: Faulty outdoor unit address

4.7 xH0: Communication malfunction between main control chip and inverter driver chip

4.8 H1: Communication malfunction between main control chip and communication chip

4.9 H2: Outdoor unit quantity is decreased

4.10 H3: Outdoor unit quantity is increased

4.11 H7: Faulty indoor unit quantity

4.12 H8: Malfunction of pressure sensor for discharge pipe

4.13 yHd: Slave unit malfunction (y refers to corresponding slave unit)

4.14 P0: Temperature protection of inverter compressor

4.15 P4: Discharge temperature protection

4.16 H6: P4 protection appears three times in 100 minutes

4.17 P1: High pressure protection

4.18 P2: Low pressure protection

4.19 H5: P2 protection appears three times in 60 minutes

4.20 xP3: Over current protection of compressor

4.21 P5: Condenser temperature protection

4.22 C7: PL protection appears three times in 100 minutes

4.22 xH4: Inverter module protection

1) L0 troubleshooting

Step 2: Module check

Check DC voltage and resistance values for module and wiring.

Step 3: DC generatrix check

2) L1;L4 troubleshooting

Step 2: Check for rectifier wiring circuit

3) L2 troubleshooting

Step 1: Check the DC voltage between terminal 1 and 2

4) L8;L9 troubleshooting

Step 1: Compressor check

Measure compressor resistance between terminals U, V, W and ground.

Step 2: Disconncet the power wiring from the compressor

Test compressor operation by connecting to a normal system.

Guide for compressor replacement

Step 1: Remove the compressor from the faulty outdoor unit

Procedure for removing the compressor and draining oil.

Step 2: Inspect system oil

Step 3: Replace the compressor

Steps for replacing the compressor and related components.

4.23 P9: Fan module protection

4.24 H9: P9 protection appears three times in 60 minutes

4.25 PL: Temperature protection of main inverter module

4.26 C7: PL protection appears three times in 100 minutes