11
Defrost System
Troubleshooting
WARNING
To avoid electrical shock or death, disconnect the power before changing the defrost time cycle or servicing the
unit.
This unit is equipped with a time/temperature defrost board. Defrosting of the outdoor coil is determined by both coil
temperature and compressor run time. Adjustment can be changed as required. There are 30, 60, and 90 minute settings
available. Adjust only if geographical conditions, outdoor humidity, or other adverse conditions make it necessary. The
maximum defrost time is 10 minutes. Most defrost cycles are shorter.
Run Time Adjustment
1. Disconnect power to outdoor unit.
2. Move the defrost time adjustment pin from 30 minutes
to 60 minutes or 90 minutes as required.
3. Reconnect the electrical power.
Rapid Advance
When servicing the unit, it may be necessary to rapidly
advance the system through a defrost cycle. To perform a
rapid advance:
1. Ensure the 24VAC power is ON.
2. Place
the defrost time adjustment pin on “TEST”.
NOTE:
If the outdoor coil temperature is above 30°F,
place a jumper wire between the “DFS” terminals
(defrost sensor) on the defrost control before placing
defrost time adjustment pin on “TEST”.
3. Reconnect electrical power to outside unit.
4. Place
the system into heating operation.
The defrost board function will speed up when the test pins
are connected. Time between defrosts will be 14 seconds.
Defrost time will be 6.5 seconds.
After servicing is completed, disconnect the power, move
the Defrost Time Select Tab back to 30, 60, or 90, remove
jumper wire on DFS, and reconnect the power.
NOTES:
1.
If the time select tab remains in TEST position for five
(5) minutes, the control will ignore TEST mode and
assume a normal defrost cycle. To override this,
briefly remove and then replace the select tab.
2.
When the unit starts the defrost cycle, quickly re-
move the time select tab to allow normal defrosting
and defrost termination to proceed. The select tab
can be reconnected to TEST to repeat the defrost
cycle, or the tab can be placed in the desired time
setting. (Jumping both test pins with a small insu-
lated screw driver will also work.)
Outdoor Thermostat
An outdoor thermostat is used to prevent full electric heater
operation at varying outdoor ambients (0°F to 45°F). The
contacts of this thermostat are normally open above its set
points and closed below to permit staging of indoor
supplemental heater operation.
If the outdoor ambient temperature is below 0°F (-18°C)
with 50% or higher relative humidity, an outdoor thermostat
(OT) must be installed and set at (0°) on the dial. Failure to
comply with this requirement may result in damage to the
product which may not be covered by the manufacturer’s
warranty.
(QUALIFIED SERVICER ONLY)
When troubleshooting, the first step should always be to check for clean
coils, clean filter(s), and proper airflow. Indoor airflow should be 350 to
450 CFM per ton of cooling, based on the size of the outdoor unit.
If further information is needed, see the Remote Heat Pump Service
Manual or contact your distributor.
Содержание REMOTE HEAT PUMP
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