6.Short between the speed-up terminals using a small, slotted screwdriver.
7.Unit changes over to defrost within 21 sec (depending on timing-cycle setting). Liquid-line temperature rises to range
where defrost-thermostat contacts open. Temperature range is from 75°F to 85°F. Resistance goes from zero to ∞ when contacts open.
8.If either opening or closing temperature does not fall within above ranges or thermostat sticks in 1 position, replace thermostat to ensure proper defrost operation.
CES0130024 DEFROST CONTROL
Some heat pumps built in 1993 and later incorporated a new defrost control similar to the CES0110063 except the 5-minute cycle protector has been removed. This control is used on heat pump units with reciprocating compressors where short-cycle protection is not required.
Troubleshooting this control will be the same as the CES0110063 control except for the cycle-protector function. The CES0130024 control is identical to the CES0110063 except the T2 terminal and cycle-protector logic have been removed.
CES0130076 DEFROST CONTROL
This defrost control is the same size as the CES0130063 control but is not backwards-compatible. (See Fig. 22.) To upgrade to the new control, you must have replacement-defrost thermostat and harness kit. See your replacement-component representative for kit part number.
Defrost Settings
The defrost control is a time/temperature control which includes a field-selectable time period (DIP switch 1 and 2 on board, see Table 11) between defrost cycles of 30, 60, 90, and 120 minutes (factory-set at 90 minutes).
TABLE 11—DEFROST TIMER SETTINGS
SW1 | SW2 | SW3 |
On | Off | 30 |
Off | On | 60 |
Off | Off | 90 |
On | On | 120 |
To initiate a forced defrost, two options are available, depending on the status of the defrost thermostat.
If defrost thermostat is closed, speedup pins (J1) must be shorted by placing a Flathead screwdriver in between for 5 seconds and releasing, to observe a complete defrost cycle. When the Quiet Shift switch is selected, compressor will be turned off for two, 30–second intervals during this complete defrost cycle. When Quiet Shift switch is in factory-default OFF position, a normal and complete defrost cycle will be observed.
If defrost thermostat is in open position and speedup pins are shorted (with a Flathead screwdriver) for 5 seconds and released, a short defrost cycle will be observed (actual length is dependent upon the selected Quiet Shift position). When Quiet Shift switch is in ON position, the length of defrost is 1 minute (30 seconds compressor-off period followed by 30 seconds of defrost with compressor operation). On return to heat operation, compressor will again turn off for an additional 30 seconds and the fan for 40 seconds. When the Quiet Shift is in OFF position, only a brief 30–second cycle will be observed.
If it is desirable to observe a complete defrost in warmer weather, the thermostat must be closed as follows.
1.Turn off power to outdoor unit.
2.Disconnect outdoor fan-motor lead from OF2 on control board. (See Fig. 22.) Tape to prevent grounding.
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3.Restart unit in heating mode, allowing frost to accumulate on outdoor coil.
4.After a few minutes in heating mode, liquid-line tempera- ture should drop below closing point of defrost thermostat (approximately 30° F.
NOTE: Unit will remain in defrost until defrost thermostat reopens at approximately 80° F coil temperature at liquid line or remainder of defrost cycle time.
5.Turn off power to outdoor unit and reconnect fan-motor lead to OF2 on control board after above forced-defrost cycle.
Compressor Shut Down
This control has the option of shutting down the compressor for 30 seconds while going into and out of defrost modes. This is accomplished by turning DIP switch 3 to the ON position. See Fig. 22 for switch position. Factory default is in the OFF position.
Five-Minute Time Delay
This control has a 5–minute time delay on startup. The speedup terminals can be used to bypass this delay. Momentary shorting across the speedup terminals will, upon release, bypass 5–minute time delay. Do not short out the speedup terminals for more than 5 seconds, or defrost mode will be initiated.
Troubleshooting
Troubleshooting this control is done in the same manner as the CES0130063 control with the exceptions listed above.
DEFROST THERMOSTAT LOCATION
On most residential, outdoor heat-pump models, the defrost thermostat is located on the return-bend side of the coil. The 5/16 OD feeder tube from the header will enter a 1–1/2 in. to 2–in. long 3/8 OD stub prior to entering the coil. There is only one stub tube per coil. All other feeder tubes enter the coil directly. The defrost thermostat attaches to this stub tube. (See Fig. 23.)
X. FAN MOTORS
Fan motor rotates the fan blade that either draws or blows air through outdoor coil to perform heat exchange. Motors are totally enclosed to increase reliability. This also eliminates need for rain shield. For the correct position of the fan blade assembly, see Fig. 24 and Table 12.
WARNING: Turn off all power to unit before servicing or replacing fan motor. Be sure unit main power switch is turned off. Failure to do so may result in electric shock, death, or injury from rotating fan blade.
The bearings are permanently lubricated; therefore, no oil ports are provided.
For suspected electrical failures, check for loose or faulty electrical connections, or defective fan-motor capacitor. Fan motor is equipped with thermal overload device in motor windings which may open under adverse operating conditions. Allow time for motor to cool so device can reset. Further checking of motor can be done with an ohmmeter. Set scale on R X 1 position; check for continuity between 3 leads. Replace motors that show an open circuit in any of the windings. Place 1 lead of ohmmeter on each motor lead. At same time, place other ohmmeter lead on motor case (ground). Replace any motor that shows resistance to ground, signs of arcing, burning, or overheating.
XI. SERVICE ALARM CONTROL BOARD
NOTE: If the proper night-setback thermostat is not used, the service-alarm control will work, but there will be no light indication on thermostat.
The service-alarm control provides immediate warning when outdoor heat pump requires servicing. It turns on indoor thermostat-malfunction light if compressor does not operate for
