Page 2 - EXAMPLE
Step 1—Self-Test Mode The control center goes through a brief self test whenever 115-v or24-v power is interrupted. The self test takes approximately 2 secto complete. After power is restored, red (microprocessor) LEDbriefly comes on. Then green LED comes on for 1 sec, followed by1 sec where both ye...
Page 4 - Fig. 1—Variable Speed Furnace Control
b. R-W/W1 with R-Y/Y2 and R-G signals terminated— The blower continues to operate completing a normalblower off delay. 11. Post purge—The inducer continues operating for 15 sec after gas valve is de-energized. Step 7—Continuous Fan Mode 1. Operating with continuous fan only. a. Call for continuous f...
Page 5 - Fig.2—Without DE Connection
When items 1-5 have been completed, the following will occur: 1. The control center goes through a brief self test. This self test takes approximately 2 sec to complete. After door switch isclosed, red (microprocessor) LED briefly comes on. Thengreen LED comes on for 1 sec, followed by 1 sec where b...
Page 7 - SERVICE
A99243a EACH OF THE FOLLOWING STATUS CODES IS A TWO DIGIT NUMBER WITH THE FIRST DIGITDETERMINED BY NUMBER OF FLASHES OF THE YELLOW LED AND THE SECOND DIGITDETERMINED BY NUMBER OF FLASHES OF THE GREEN LED. Furnace is operating in emergency heat.The microprocessor has malfunctioned. To reset: Put setu...
Page 8 - Fig. 4—Service Label/Fault Code Instructions; COMPONENT TEST; STATUS CODE EXAMPLE
→ Fig. 4—Service Label/Fault Code Instructions A99243b A99243 To initiate the component test sequence, shut "OFF" the room thermostat or disconnect the "R"thermostat lead. Put setup switch "SW-6" in the "ON" position to start the component test sequence.Once initiated...
Page 12 - RED LED2 FLASHING—Indicates line voltage polarity is reversed.
28. Put setup switch SW-1 back in OFF position. — — 29 29. Jumper R and W/W1 thermostat terminals. — — 30 30. Does RED LED2 turn back ON? 7 31 — 31. Install isolation relays in the W/W1 and Y/Y2 circuits per Fig. 5 in Appendix B or replace thermostat. — — 8 32. Was RED LED2 ON before you started Ste...
Page 19 - Table 3—Continuous Fan (CF) Airflow Setup Switch Position
Fault Code 24 SECONDARY VOLTAGE FUSE IS OPEN—Indicates fuse is open and there is a short in low-voltage wiring. STEP ACTION YES NO GO TO 1. Turn power off and remove blower access panel. — — 2 2. Is secondary voltage fuse blown? Check continuity to make sure. 5 3 — 3. Replace furnace control board. ...
Page 26 - IGNITION PROVING FAULT—This fault can indicate 1 of the following:
Fault Code 34 IGNITION PROVING FAULT—This fault can indicate 1 of the following: • Flame was not sensed during trial for ignition period. The control will repeat ignition sequence 3 more times before going into Fault14—IGNITION LOCKOUT. • The flame signal was lost after trial for ignition period. • ...
Page 34 - Appendix A; Board Layout and Schematic; Control Center
Appendix A Board Layout and Schematic W2 COM 24V W/W2 Y/Y2 RG HUM HOT SURFACE IGNITOR CONNECTOR EAC-ELECTRONIC AIR CLEANER TERMINALS (115-VAC 1 AMP MAX) 115-VCONNECTORS(SEE DETAILS ABOVE) 24-V THERMOSTATTERMINALS PRESSURE SWITCHCONNECTOR HUM-HUMIDIFIERTERMINAL(24-VAC 0.5 AMP MAX) TRANSFORMER 24-V CO...
Page 36 - Appendix B; Isolation Circuits; Thermostat Circuits; Fig. 6—Isolation of Outdoor Unit with a Separate; Appendix C; Pressure Check Diagram
Appendix B Isolation Circuits THERMOSTAT FURNACE CONTROL BOARD K 1 K 1 K 2 K 2 OUTDOOR UNIT K 1 K 2 FIELD-SUPPLIED24-VAC SPST RELAYS R W Y G C R Y / Y2 W / W1 G Com Y C A95097 Fig. 5—Isolation of W/W1 and Y/Y2 Thermostat Circuits THERMOSTAT FURNACE CONTROL BOARD K 1 K 1 K 1 –FIELD-SUPPLIED 24-VAC SP...
Page 37 - Appendix D; Quick Motor Test Procedure
Appendix D Quick Motor Test Procedure In an effort to provide a method of troubleshooting inducer and blower motor by themselves, the following procedure may save you some timein the event any of the following fault codes are the reason for service call (12, 32, 41, 42, or 44). If you get any other ...
Page 40 - Appendix E; Variable-Speed Condensing Furnace Duct Static and Blower
Appendix E Variable-Speed Condensing Furnace Duct Static and Blower Operation This variable-speed furnace has an Integrated Control and Motor called an ICM. This ICM is controlled as stated in Sequence of Operationsection. This furnace does a good job compensating for an improperly sized duct system...
Page 41 - Air Delivery Curves
A97320 0.8 0.7 0.6 0.5 0.4 0.3 LOW HEAT HIGH HEAT Constant System Curves External Static Pressure (in. wc) 2 Ton 3 Ton 3 1 ⁄ 2 Ton 2 1 ⁄ 2 Ton 0.2 0.1 0 500 600 700 800 900 1000 1100 CFM 1200 1300 1400 1500 1 1 ⁄ 2 Ton Air Delivery Curve — 080-14 A93074 0.8 0.7 0.6 0.5 0.4 0.3 LOW HEAT HIGH HEAT Con...
Page 42 - Static Pressure Reading Location Diagrams
Downflow Total Static Pressure Reading Locations A95091 Closet — Downflow Application ELECTRONIC AIR CLEANER HUMIDIFIER A/C COIL VENT COMBUSTIONAIR OUTDOORUNIT AIRFLOW RETURN STATIC INCLINE MANOMETER SUPPLY STATIC INCLINE MANOMETER Upflow Total Static Pressure Reading Locations A95090 Basement — Upf...
Page 43 - Attic — Horizontal Application; Example 1
Tools Needed: 1) Pitot Tube 1) Incline Manometer/Magnahelic Both examples are correct. Example 1 ESP readings were taken aslaid out in Static Pressure Reading Location Diagrams. Example 2readings are taken as described. The coil and filter static pressuredrops were taken from the manufacturer’s Prod...
Page 44 - Duct Static Check Sheet
Duct Static Check Sheet Furnace:Model NumberSerial NumberPosition? U/F D/F H/R H/L Indoor Coil:Model NumberSerial Number Outdoor Unit:Model NumberSerial Number ThermostatElectronic Air Cleaner What type of media filter is being used?What is static pressure drop across filter? At what CFM? Does fault...
Page 45 - Appendix F; Quick Reference Information
Appendix F Quick Reference Information PRESSURE SWITCH MAKE/BREAK POINTS UNIT SIZE (BTUH) HIGH-PRESSURE SWITCH LOW-PRESSURE SWITCH Make Point Break Point Make Point Break Point 40,000 1.81 in. wc max 1.63 in. wc ± 0.05 0.75 in. wc max 0.60 in. wc ± 0.05 60,00080,000 100,000120,000 1.81 in. wc max 1....
Page 46 - Appendix G; Thermostat Staging Algorithm
Appendix G Thermostat Staging Algorithm • Unit Default: Algorithm is initiated with Low Heat for 16 minutes. If call for heat still exists, unit transfers into High Heat until thermostatis satisfied. • Low Heat run time is calculated based on previous heating cycle. • High Heat on time is not calcul...
Page 47 - VARIABLE SPEED CONDENSING FURNACE ALGORITHM
A95094 VARIABLE SPEED CONDENSING FURNACE ALGORITHM Using re corded Low Heat (LH) and High Heat (H H) val u es, calcu la te the Heat Lo ad (HL) usin g: HL=(228 X LH) + (350 X HH ) Is HL < 36 48 ? Is HL > 56 00 ? Is 5 6 0 0 > HL > 3 648 ? Calculate Low Heat (LH) on time will be 16 m inutes...
Page 48 - SERVICE TRAINING; • Unit Familiarization
A94328 SERVICE TRAINING Packaged Service Training programs are an excellent way to increase your knowledge of the equipment discussed in this manual, including: • Unit Familiarization • Maintenance • Installation Overview • Operating Sequence A large selection of product, theory, and skills programs...