43 68-0173—3
Fig. 41. Troubleshooting procedures (Continued).• CHECK SYSTEM FUSE OR CIRCUIT BREAKER AND
REPLACE OR RESET IF NECESSARY.
• CHECK THAT COOL SYSTEM POWER IS ON.
• CHECK FOR LOOSE CONNECTIONS AT PC8900, W8900,
C7189, OR EQUIPMENT.
• RECONFIGURE PC8900 FOR HUMIDITY CONTROL IN HEATING
(APPLIES TO W8900A,B ONLY).
PC8900 IS CONFIGURED FOR FROST
CONTROL.
HUMIDITY SETTING IS TO LOW. • ADJUST HUMIDITY SETTING USING AND KEYS.
• TO PREVENT FROST FROM FORMING ON WINDOWS, SOME
CALLS FOR HUMIDIFICATION WILL NOT BE ALLOWED. REFER
TO INSTALLATION AND OPERATION SECTION.
HUMIDIFICATION EQUIPMENT
WILL NOT COME ON IN
HEATING.
NO POWER TO HUMIDIFIER.
NO POWER TO W8900.
• CHECK SYSTEM FUSE OR CIRCUIT BREAKER AND REPLACE
OR RESET IF NECESSARY.
• CHECK THAT EQUIPMENT POWER IS ON.
• CHECK FOR LOOSE CONNECTIONS ON EQUIPMENT, PC8900
AND W8900.
PC8900 IS NOT CONFIGURED PROPERLY.
GREEN LED ON W8900 IS NOT
OPERATING.
• RECONFIGURE PC8900 FOR HUMIDITY CONTROL IN COOLING
(APPLIES TO W8900A,B ONLY).
EQUIPMENT COMPRESSOR PROTECTION
ACTIVATED.
HUMIDITY SETTING IS TO HIGH. • ADJUST HUMIDITY SETTING USING AND KEYS.
• EQUIPMENT HAS A MINIMUM-OFF TIME TO PROTECT THE
COMPRESSOR (IF ACTIVATED). ALLOW UP TO FIVE MINUTES
AFTER CHANGING THE SETTING BEFORE THE COMPRESSOR
STARTS.
DEHUMIDIFICATION EQUIPMENT
(COOLING) WILL NOT COME ON
IN COOLING.
NO POWER TO DEHUMIDIFIER (COOLING)
EQUIPMENT.
• CHECK SYSTEM FUSE OR CIRCUIT BREAKER AND REPLACE
OR RESET IF NECESSARY.
• CHECK THAT EQUIPMENT POWER IS ON.
• CHECK FOR LOOSE CONNECTIONS ON EQUIPMENT PC8900
AND W8900.
PC8900 IS NOT CONFIGURED PROPERLY.
• RECONFIGURE PC8900 FOR VNT OR OUTSIDE AIR DAMPER.
VENTILATION EQUIPMENT
WILL NOT COME ON.
NO POWER TO VENTILATION
EQUIPMENT.
• CHECK SYSTEM FUSE OR CIRCUIT BREAKER AND REPLACE
OR RESET IF NECESSARY.
• CHECK THAT EQUIPMENT POWER IS ON.
• CHECK FOR LOOSE CONNECTIONS AT PC8900, W8900 OR
VENTILATION EQUIPMENT.
PC8900 IS NOT CONFIGURED PROPERLY.
• RECONFIGURE PC8900 FOR F.
TEMPERATURES ARE
DISPLAYED IN C.
PC8900 IS NOT CONFIGURED PROPERLY.
VENTILATION EQUIPMENT IS
RUNNING INDEPENDENT
OF PC8900.
A REMOTE SWITCH IS CALLING FOR
VENTILATION.
A HIGH CO
2
CONDITION EXISTS IN THE
LIVING SPACE.
SYMPTOM POSSIBLE CAUSE ACTION
• WHEN CO
2
SENSOR SENSES HIGH CO
2
CONDITION, SYSTEM
FAN AND VENTILATION ARE ACTIVATED TO VENTILATE LIVING
SPACE.
M18744
• RECONFIGURE PC8900 FOR 12 HOUR CLOCK.
TIME IS DISPLAYED IN MILITARY
TIME (EX: 14:00).
PC8900 IS NOT CONFIGURED PROPERLY.
• TURN REMOTE SWITCH OFF.
DISCHARGE AIR TEMPERATURE
NOT DISPLAYED WHEN CHECK
KEY IS PRESSED.
POWER OUTAGE HAS REMOVED
DISCHARGE AIR TEMPERATURE
FROM DISPLAY.
PC8900 IS NOT CONFIGURED FOR
DISCHARGE AIR TEMPERATURE. • RECONFIGURE PC8900 FOR DISCHARGE AIR TEMPERATURE.
• ENTER INSTALLER SET UP MODE FOR A FEW SECONDS.
AFTER LEAVING SET UP MODE, DISCHARGE AIR
TEMPERATURE IS DISPLAYED UNTIL NEXT POWER OUTAGE.