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OUTDOOR TECHNICAL OVERVIEW

B-1

ENGLISH

OUTDOOR TECHNICAL OVERVIEW

Components ......................................................................................................................................................................... B-2

Service Monitor Board (SMB) .............................................................................................................................................. B-2

Module Circuit Board (MCB) ................................................................................................................................................ B-2

Electronic Control Unit Circuit Board (ECU) ....................................................................................................................... B-3

Power Circuit Board (PCB) ................................................................................................................................................... B-4

Outdoor Fan Motor .............................................................................................................................................................. B-5

Low Pressure Switch............................................................................................................................................................ B-5

4 Way Valve .......................................................................................................................................................................... B-5

High Pressure Switch ........................................................................................................................................................... B-5

Compressor ......................................................................................................................................................................... B-6

EEV Valves............................................................................................................................................................................ B-6

Crankcase Heater ................................................................................................................................................................ B-6

Temperature Sensors .......................................................................................................................................................... B-7

Operations............................................................................................................................................................................ B-8

Cooling Mode Sequence of Operation ............................................................................................................................... B-8

Heating Mode Sequence of Operation ............................................................................................................................. B-10

Outdoor Frequency Control ............................................................................................................................................. B-12

Electronic Expansion Valve (EEV) Control ........................................................................................................................ B-12

Valve Adjustments Due To Hot Gas Discharge Temperature Limits .............................................................................. B-12

4-Way Valve Control During Heating Mode ..................................................................................................................... B-12

Crankcase Heater Control ................................................................................................................................................. B-12

On Demand Defrost Logic ................................................................................................................................................ B-12

Initiating Forced Defrost Operation ................................................................................................................................. B-13

Defrosting Time Flowchart ............................................................................................................................................... B-13

Frequency Control and Compressor Discharge Line Temperature ................................................................................ B-13

Frequency Control when there is CT Over-current Protection ...................................................................................... B-13

High Pressure Protection .................................................................................................................................................. B-13

Low Pressure Protection ................................................................................................................................................... B-13

Forced Defrost Operation ................................................................................................................................................. B-14

Preventing Compressor Overcurrent .............................................................................................................................. B-14

The Protection Function of AC Current: .......................................................................................................................... B-14

Antifreezing Protection of the Indoor Heat Exchanger ................................................................................................... B-14

Testing ................................................................................................................................................................................ B-15

Outdoor Fan Motor ............................................................................................................................................................ B-15

Temperature Sensor .......................................................................................................................................................... B-15

4-Way Valve ....................................................................................................................................................................... B-16

Electronic Expansion Valve (EEV) ..................................................................................................................................... B-16

Variable Speed Compressor ............................................................................................................................................. B-17

Wiring Error Check ............................................................................................................................................................. B-17

Wiring Diagrams ................................................................................................................................................................. B-18

DIP Switch Settings ............................................................................................................................................................ B-21

Error Codes ......................................................................................................................................................................... B-23

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