Page 12
2-pipe Control Logic
–
without Valve
COOL MODE
When unit is turned on in cooling mode:
If Tr ≥ Ts + 1ºC (Modbus 300033 setting), AUX1 is closed. Fan is turned on at setting
speed. If Tr < Ts, then cool operation is terminated and AUX1 is turned off. Indoor fan runs at super low speed.
When unit is turned off, AUX1 is off. Fan is turned off after 30s.
The range of Ts is 16 - 30ºC.
Indoor fan speed can be adjusted to low, medium, high and auto.
LOW TEMPERATURE PROTECTION OF INDOOR COIL IN COOLING MODE
If Ti1 ≤ 2 ºC for 2 minutes, indoor fan is set at Medium speed if fan runs at low speed.
If Ti1 ≥ 5ºC for 2 minutes, indoor fan is changed to set speed.
FAN MODE
Indoor fan speed can be adjusted for low, medium and high. If fan speed is set at auto by Modbus, fan will run at low speed.
HEAT MODE
Without Electrical Heater (Modbus300043=0)
When unit is turned on in heating mode:
a)
When
Tr ≤ Ts
- 1 ºC (Modbus 300033 setting), AUX2 is turned on and check Ti1 in 2 minutes:
If Ti1 < 28ºC (Modbus 300017 setting), fan is turned on at low speed.
If 28ºC<Ti1< 28(Modbus 3000017 setting) + 4ºC, fan is on at original state.
If Ti1 ≥ 28(Modbus 3000017 setting) + 4ºC, fan is on at setting speed.
If Ti1 sensor is damaged, fan works at setting speed.
b)
When Tr > Ts+1ºC (Modbus 300033 setting), AUX2 is turned off. Fan runs at lowest speed.
When unit is turned off,
AUX2 is turned off. Fan works at setting speed. If Ti1≥38 ºC, fan is turned off after 2 minutes.
With Electrical Heater as booster (Modbus300043=1)
When unit is turned on in heating mode:
a)
When Tr ≤ Ts
- 1 ºC (Modbus 300033 setting), AUX2 is turned on. Fan is turned on at setting speed, then check Ti1 in 2
minutes:
If Ti1 < 28ºC (Modbus 300017 setting), EH is turned on.
If 28ºC<Ti1< 28 (Modbus 3000017 setting) +4ºC, EH is kept at original state.
If Ti1 ≥ 28(Modbus 3000017 setting) + 4ºC, EH is turned of
f.
If Ti1 sensor is damaged, fan will run at set speed.
b)
When Tr > Ts+1 ºC (Modbus 300033 setting), AUX2 is turned off. EH is turned off. Fan is turned on at low speed.
When unit is turned off, AUX2 is turned off. Fan is turned off after 2 minutes.
With Electrical Heater as primary heat source (Not available)
OVER-HEAT PROTECTION OF INDOOR COIL
If Ti1 ≥ 75ºC, then AUX
2 is turned off. Indoor fan remains on and runs at high speed.
If Ti1 < 70ºC, then unit keep original state.
If the indoor coil temperature sensor is damaged or not connected, the protection mode will be overridden and the unit
will work according to the pre-heat and post-heat program.
DEHUMIDIFICATION MODE
When dehumidification mode is on, AUX1 is turned on and fan is turned on at low speed.
AUTO MODE (Not available)
2019-IOM-SWC-V-EC-I-001
