This service manual is made to assist the service technician apply his knowledge and training to this model air conditioner. This manual is written both for experienced service persons and those who are new to air conditioning service. To help those with less experience or who are new to this kind of unit we have included more explanations of basic procedures in simple language than is usual in some service manuals. The experienced technician will of course find he knows many of these things already and can go directly to the procedures and information he needs; the less experienced technician will better understand what to do even before he arrives on the job, and therefore be better able to work by himself as well as assist the more experienced technician. 1. SPECIFICATIONS.................................................................................................5 1-1 Unit Specifications.........................................................................................6 1-2 Major Component Specifications.....................................................................8 (A) Indoor Unit...............................................................................................8 (B) Outdoor Unit.............................................................................................9 1 -3 Other Component Specifications...................................................................10 (A) Indoor Unit..............................................................................................10 (B) Outdoor Unit...........................................................................................11 1 -4 Dimensional Data........................................................................................12 (A) Indoor Unit..............................................................................................12 (B) Outdoor Unit...........................................................................................13 1 -5 Refrigerant Flow Diagram.............................................................................14 1 -6 Operating Range..........................................................................................14 2. PROCESSES AND FUNCTIONS..........................................................................15 2-1 Room T emperature Control.........................................................................16 2-2 Freeze Prevention........................................................................................17 2-3 Drain Pump Control.....................................................................................17 2-4 Outdoor Fan Speed Control..........................................................................18 3. ELECTRICAL DATA ...........................................................................................19 3-1 Indoor Unit..................................................................................................20 3-2 Outdoor Unit.................................................................................................22 4. SERVICE PROCEDURES ...................................................................................23 4-1 Troubleshooting...........................................................................................24 4-2 A Sensor is Defective...................................................................................34 4-3 Operation of Major Electrical Parts................................................................34 4-4 Checking the Electrical Components.............................................................35