20
● Manual Defrost:
1. System must have a call for heat and have been operating for a minimum of 8 minutes.
2. Press “Force” button on inverter board for 6 seconds to begin forced defrost.
3. Wait approximately 40 seconds for defrost to initiate.
4. Once defrost initiates, the display will indicate “dF”.
5. Defrost test will terminate automatically, after which the display will indicate running speed.
6. If a second defrost test is required, repeat step 3 after 5 minutes.
3.Defrost description
● The Demand Defrost Control (DDC) monitors the ODU coil temperature using thermistor (T3). A second
thermistor (T4) monitors outdoor ambient temperature. Based on these parameters, as well as accumulative
run time and high pressure, the DDC calculates proper initiation of defrost.
● The following three conditions are required to enter defrost:
① Outdoor coil temperature T3 < 34F and a corresponding minimum outdoor ambient temperature is met.
② After “Minimum Run Time” (MRT) is achieved. MRT is based on outdoor ambient temperature (T4),
for example
• MRT is 4 hours when: T4 < -23F
• MRT is 2 hours when: -23F ≤ T4 < 42F
③ After the high pressure saturation temperature drops below 82F for 20 minutes.
● Defrost will terminate once outdoor coil temperature (T3) reaches 64F for a period of 1 minute or defrost
time has exceeded 8 minutes.
● Defrost Termination Settings (SW5) offers different defrost termination options for enhanced defrost for
different geographical &/or outdoor conditions.
Def rosting choice
SW5-1
SW5-2
Remarks
ON
OFF Normal
Normal
Default
Remarks
Enter defrost
Quit defrost
ON
OFF
1 2
SW5
Operating time is
reduced by 10%
Defrosting extended
for 60 seconds
To Next Page
Loading...