25
Low pressure protection
When low pressure is
＜
21PSIG,the compressor and the outdoor fan motor
will stop running.
When low pressure is
＞
44PSIG,the compressor and the outdoor fan motor
will resume running(3 minutes delay necessary ).
In stand-by status, if low pressure protection was detected, the compressor
will not start.
If protection cycles occur four times within 30 minutes, the compressor and
outdoor fan will shut down. In this condition, the system needs to power on
T4 function:
When T4 is < 5 °F, the compressor will stop. If the electrical heater kit is installed
in the indoor unit, the outdoor unit will send the operation signal to the indoor unit.
When T4 is > 10.4 °F, the compressor will restart .
once more in order to keep on working.
8.3 DEFROST MODE INTRODUCTION (Heat pump only)
Fig.11 SW3 Switch Location in the PCB Board
（
For reference only
)
SW3 Switch
Manual defrost mode
To manually cycle the defrost mode, set switch SW3-1 to the “ON” position
(See Fig 11). The system will engage a defrost cycle, and automatically exit
defrost mode once the
Shut-down conditions of defrost mode
described
below are met.
Caution
: Once the manual defrost mode is finished, please set switch SW3-1
back to “OFF”.
Start-up conditions of defrost mode:
When SW3-3 switch is set to “ON”(See Fig 11), the system will perform a defrost
cycle in any of the following conditions:
1. If the compressor is operating and T3 is < 30.2 °F, the system will perform a
defrost cycle every 30 minutes of operation.
2.When T3 is < 28.4 °F and the compressor is operating for the first time after
being connected power.
3. When T3 is < 28.4 °F and the system has been in standby for two hours .
MANUAL DEFROST
AUTOMATIC DEFROST
NORMAL DEFROST
DEFROSTING CYCLE:60MIN
DEFROSTING CYCLE:30MIN
RESERVED
When SW3-3 switch is set to “OFF”(See in Fig 11), the system will perform a
defrost cycle in any of the following conditions:
1. If the compressor is operating and T3 is < 30.2 °F, the system will perform a
defrost cycle every 60 minutes of operation.
2.When T3 is < 28.4 °F and the compressor is operating for the first time after
being connected power.
3. When T3 is < 28.4 °F and the system has been in standby for two hours .