Way Valve Adjustment Control - Panasonic U-120ME2U9 Service Manual

8. 4-Way Valve Adjustment Control

8. 4-Way Valve Adjustment Control
The purpose of this control is to change over the 4-way valve appropriately with big pressure difference.
This control is performed at the following conditions.
The first operation after turning on power supply to outdoor unit.
The first operation after all outdoor units stopped for 60 minutes.
The mode of the system changes.
Cooling operation
Control time
Outdoor units
1
Indoor units
2
* When the above operation is finished, normal operation starts at the horsepower determined by the indoor units
where thermostats are ON.
Heating operation
3
Control time
Outdoor units
MOV
4
RAP valve kit
Fan
5
* When the above operation is finished, normal operation starts at the horsepower determined by the indoor units
where thermostats are ON.
6
7
8
9
For 2 minutes
All outdoor units operate at the maximum capacity.
MOV at all indoor units operate at a fixed pulse according to the indoor unit
MOV
capacity.
RAP valve kit All indoor units operate in Cooling mode (OFF status).
・Stop and cooling (thermostat ON/OFF) operation of indoor units will be
followed the indoor unit control system.
Fan
・Fan operation of indoor unit is changed to LL.
Minimum 1 min - Maximum 20 min [until max. (pressure sensor temp.) 95°F (35°C)]
All outdoor units operate at the maximum capacity.
MOV at all indoor units operate at 250 pulses.
All indoor units operate in heating mode (ON status).
・As for heating thermostat ON indoor units, follow the indoor unit control system.
・Fan and heating (thermostat OFF) operation of indoor unit will be stopped.
・The fan speed of heating thermostat OFF Concealed Duct - High Static type indoor
unit (Type E1) is changed to LL.
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2WAY VRF SYSTEM
2WAY VRF SYSTEM
Control Functions
Control Functions