Way Valve Adjustment Control - Panasonic U-8ME1E81 Service Manual

8. 4-Way Valve Adjustment Control

8. 4-Way Valve Adjustment Control
This control is to change over the 4-way valve appropriately with big differential pressure.
8-1. Start of 4-way valve adjustment control
When the microcomputer is initialized immediately after power-ON.
After warning output occurs
After a set amount of time has elapsed 60 minutes when all outdoor units are stopped.
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8-2. Simplified flow of 4-way valve adjustment control
8-2-1. Whole Process
Tube refrigerant recovery control shall be performed as the flow mentioned below.
(0) Stopped
(1) 4-way valve adjustment control processing time
(2) Post-processing time of 4-way valve adjustment control for non stop operation
(3) Normal operation
8-2-2. 4-way valve adjustment control Process
(1) Control when the outdoor unit heat exchanger is acting as a condenser
Control time
Outdoor units
All Indoor Units
* When the above operation is finished, normal operation starts at the horsepower determined by the indoor units
where thermostats are ON.
(2) Control when the outdoor unit heat exchanger is acting as an evaporator
Control time
Outdoor units
Electronic control valve
All Indoor Units
Fan
* When the above operation is finished, normal operation starts at the horsepower determined by the indoor units
where thermostats are ON.
Electronic control valve
Fan
Minimum 1 minute – Maximum 21 minutes (Until Tc
All outdoor units operate at maximum horsepower.
Valves at all indoor units operate at 250 pulses.
As for heating thermostat ON indoor units, follow the indoor unit
control system.
The fan speed of the heating thermostat OFF high static pressure
ducted type indoor unit (Type E1) is changed to LL.
Fan and/or heating (thermostat OFF) operation of indoor unit will be
stopped.
2 minutes
All outdoor units operate at maximum horsepower.
Valves at all indoor units operate at a fixed pulse according to
the indoor unit capacity.
Fan operates at the set fan speed depending on the indoor unit
operation mode.
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2WAY SYSTEM
2WAY SYSTEM
Control Functions-Outdoor Unit Control Functions - Outdoor Unit
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35°C)