Discharge Tube Accumulated Refrigerant Recovery Control - Panasonic U-72MF2U9 Service Manual

10. Discharge Tube Accumulated Refrigerant
Recovery Control
10-1. Start of Discharge Tube Accumulated Refrigerant Recovery Control
When any of them is completed, this control is implemented.
(1) More than 90 minutes, more than one indoor unit for judgment of discharge tube accumulated refrigerant
(2) More than 60 minutes, indoor unit for judgment of discharge tube accumulated refrigerant :
Indoor unit total amount ≥ 1/3 thermostat ON HP
(3) More than 30 minutes, indoor unit for judgment of discharge tube accumulated refrigerant :
Indoor unit total amount ≥ 1/3 thermostat ON HP
Judgment of discharge tube accumulated refrigerant
● Indoor unit operating mode with cooling thermostat ON
● Indoor unit electronic control valve opened more than 300 pulses
● Difference between suction temperature and discharge temperature is less than 5.4deg F (3deg C).
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10-2. Simplified Flow of Discharge Tube Accumulated Refrigerant Recovery Control
● Whole process
Discharge tube accumulated refrigerant recovery control shall be performed as the flow mentioned below.
(0) Normal operation
2
(1) Time before discharge tube accumulated refrigerant recovery control 3.0 minute stop
(2) Discharge tube accumulated refrigerant recovery control processing time *
(3) Time after discharge tube accumulated refrigerant recovery control 4 minute stop
(4) Normal operation
3
* 1 Discharge tube accumulated refrigerant recovery control process
This discharge tube accumulated refrigerant recovery control process is performed after outdoor units, indoor
units and solenoid valve kits are changed to the heating mode.
Control time
4
Outdoor unit
Expansion valve
All
5 Indoor Solenoid Valve Kit
Units
6
7
8
9
Minimum 1 minute – Maximum 5 minutes
(Until all outdoor unit's HPT ≥ 68°F (20°C))
Outdoor unit operates at maximum horsepower.
Valves at all indoor units operate at 250 pulses.
Valve kits at all indoor units operate in heating mode (ON status).
· As for stop and heating indoor units, follow the indoor unit control system.
Fan
· Fan and cooling indoor unit will be stopped.
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3WAY VRF SYSTEM
Control Functions