PACD011001C2 Function
Function Urban Multi “MX1R, ME1R Series” Using R-407C 253
1.11 HR Changeover Control (ME1R Series)
The solenoid valve of the HR box is switched according to the indoor unit operating condition.
When the solenoid is operable, if the operating condition differs from the solenoid condition, the solenoid is
switched according to the above table.
However, the following conditions take precedence.
Condition 1
Normal operation Oil return, defrost
Cooling
Condition 2
Heating
Condition 3
Condition 4
Oil return, defrost
Oil return, defrost complete
Discharge defrost
Discharge oil return
Suction defrost
Suction oil return
(VF006)
Condition Indoor unit operating condition Y3S Y2S Y1S
ON: Open
OFF: Closed
1 Cooling
Heating stop
∗
1
OFF ON OFF
2 Heating thermostat OFF
Heating thermostat ON
ON OFF
∗
2
3 Discharge oil return OFF OFF OFF
4 Suction oil return
Defrost
ON ON OFF
∗
1 : Condition 2 results in heating stop units when no unit in the system is in cooling operation.
∗
2 : Condition 1 results when a unit connected to the HR box is in heating thermostat ON condition
during simultaneous cooling/heating operations.
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