Page 28 of 57
SK2016 HW-V-AECM-001
D.5.
Control Logics For 4-Pipe System
Note: unit equipped with 4x2 switching device.
COOL MODE
a)
MTV2, AUX1 and Electrical Heater are always off.
b)
If Tr ≥ Ts + 1.8ºF (or + 7.2ºF if economy contact is activated), then cool operation is activated, MTV1
and AUX2 are turned on. Indoor fan runs at set speed.
c)
If Tr < Ts, then cool operation is terminated, MTV1 and AUX2 are turned off. Indoor fan runs at set
speed.
d)
The range of Ts is 60.8 - 86ºF
e)
Indoor fan speed can be adjusted to low, medium, high and auto.
f)
When turned on, MTV1 requires 30 seconds before it is fully open.
g)
When turned off, MTV1 requires 120 seconds before it is fully closed.
h)
When the unit is turned off, the indoor fan will shut down after 5 seconds.
FAN MODE
a)
Indoor fan runs at the set speed while heater, MTV1, MTV2, AUX1 and AUX2 are turned off.
b)
Indoor fan speed can be adjusted to low, medium and high.
HEAT MODE
Without Electrical Heater
a)
MTV1, AUX2 and electric heater are always off.
b)
If Tr ≤ Ts – 1.8ºF (or – 7.2ºF if economy contact is activated), then heat operation is activated and MTV2
and AUX1 are turned on. Indoor fan runs at the set speed.
c)
If Tr > Ts, then heat operation is terminated and MTV2 and AUX1 are turned off. Indoor fan runs at
200RPM.
d)
The range of Ts is 68.8 - 86ºF.
e)
Indoor fan speed can be adjusted to low, medium, high and auto.
f)
When turned on, MTV2 requires 30 seconds before it is fully open.
g)
When turned off, MTV2 requires120 seconds before it is fully closed.
With Electrical Heater as Booster
a)
MTV1 and AUX2 are always off.
b)
If Tr ≤ Ts – 1.8ºF (or – 7.2ºF if economy contact is activated), then heat operation is activated and MTV2
and AUX1 are turned on. Indoor fan runs at the set speed.
c)
If Tr > Ts, then heat operation is terminated and MTV2 and AUX1 are turned off. Indoor fan runs at
200RPM.
d)
If Ti1 < 104ºF, then the electrical heater is turned on. If 104ºF ≤ Ti1 < 113ºF, then the electrical heater
maintains its original state. If Ti1 ≥ 113ºF, then the electrical heater is turned off.
e)
The range of Ts is 60.8 - 86ºF.
f)
Indoor fan speed can be adjusted to low, medium, high and auto.
g)
When turned on, MTV2 requires 30 seconds before it is fully open.
h)
When turned off, MTV2 requires120 seconds before it is fully closed.
PRE-HEAT
Without Electrical Heater
a)
If Ti1 < 96.8ºF [or 82.4ºF depending on DIP setting], then MTV2 and AUX1 are turned on. Indoor fan
runs at 200RPM.
b)
If Ti1 ≥ 100.4ºF [or 86ºF depending on DIP setting], then MTV2 and AUX1 are turned on. Indoor fan
runs at set speed.
c)
If indoor coil temperature sensor is damaged, then the pre-heat time is set for 2 minutes. Indoor fan
runs at set speed.
