Mitsubishi Electric CITY MULTI PUHY-400YMF-B, Service Handbook, Page: 2 / 204

Contents
1
PRECAUTIONS FOR DEVICES
THAT USE R407C REFRIGERANT ......................................... 1
[1] Storage of Piping Material ............................................. 2
[2] Piping Machining ........................................................... 3
[3] Necessary Apparatus and Materials and Notes on
Their Handling ............................................................... 4
[4] Brazing ........................................................................... 5
[5] Airtightness Test ............................................................. 6
[6] Vacuuming ..................................................................... 6
[7] Charging of Refrigerant ................................................. 7
[8] Dryer .............................................................................. 7
2
COMPONENT OF EQUIPMENT ............................................. 8
[1] Appearance of Components .......................................... 8
[2] Refrigerant Circuit Diagram and Thermal Sensor ........ 18
[3] Equipment Composition ............................................... 22
[4] Electrical Wiring Diagram ............................................. 24
[5] Standard Operation Data ............................................. 27
[6] Function of Dip SW and Rotary SW ............................ 39
3
TEST RUN ............................................................................. 45
[1] Before Test Run ........................................................... 45
[2] Test Run Method .......................................................... 52
4
GROUPING REGISTRATION OF INDOOR UNITS WITH
REMOTE CONTROLLER ...................................................... 53
5
CONTROL .............................................................................. 59
[1] Control of Outdoor Unit ................................................ 59
[2] Operation Flow Chart ................................................. 109
[3] List of Major Component Functions ........................... 114
[4] Resistance of Temperature Sensor ............................ 118
6 REFRIGERANT AMOUNT ADJUSTMENT ......................... 119
[1] Operating Characteristics and Refrigerant Amount ... 119
[2] Adjustment and Judgement of Refrigerant Amount ... 119
[3] Refrigerant Volume Adjustment Mode Operation ....... 122
7
TROUBLESHOOTING ......................................................... 129
[1] Principal Parts ............................................................ 129
[2] LED monitor display and Countermeasures
Depending on the Check Code Displayed ................. 158
[3] LED Monitor Display .................................................. 179