3.4.1 Oil return program
a) When system start up for 140 minutes, oil return program will run. After that, every 8 hours continued operating this program
will run.
b) The program will last for 3 minutes.
c) The outdoor EXV open to 480 pulse.
d) Action of indoor Fan and EXV.
3.4.2 Forced cooling program
a) After pressing it once, all indoor units and outdoor units will start cooling, no matter what mode they are running on, no matter
whether they are ON or OFF.
b) During forced cooling mode.
i. All indoor EXVs open to 480 pulses.
ii. All indoor fans are in high speed..
iii. All outdoor fan motors are open.
iv. Outdoor EXV opens to 480 pulses.
c) When the process is last for 1h or the button is pressed again, program will quit.
3.4.3 Defrost program
a) When any module’s condenser temperature (T3) < -2, last for 40minutes, this outdoor unit sends defrost order to outdoor unit.
b) Before defrost, save current EXV opening pulses. EXV opening pulses will be recover when defrost program ends.
c) During defrosting.
i. All indoor EXVs open to 480 pulses.
ii. All indoor fans are anti-cold program.
iii. Compressor is ON.
iv. Outdoor fan motors are OFF
v. Outdoor EXVs open to 480 pulses.
d) It ends when in the following conditions :
i. The defrosting time is up to 10 minutes.
ii. All module’s condenser temperature (T3)≥15 ℃.
iii. T3≥7℃ last for 60 seconds.
e) After defrost.
i. All indoor units’ EXV recover to save pulse.
ii. All indoor fans return to normal control.
iii. Compressor returns to normal control.
iv. All outdoor fan motors return to normal control.
v. Outdoor EXVs return to normal control..