Low Hz High Pressure Limit; Outdoor Electronic Expansion Valve Control - Daikin SUPER MULTI NX CTXS07JVJU Service Manual

Control Specification

3.11 Low Hz High Pressure Limit

Outline
The system controls the upper limit of the frequency to prevent abnormal high pressure while the
frequency is low.
Control is carried out according to three zones.
Detail
Note: Dropping: The system stops 2 minutes after staying in the dropping zone.

3.12 Outdoor Electronic Expansion Valve Control

Outline The following items are included in the outdoor electronic expansion valve control.
Outdoor electronic expansion valve is fully closed
1. Outdoor electronic expansion valve is fully closed when turning on the power.
2. Pressure equalizing control
Room Distribution Control
1. Gas pipe isothermal control
2. SC (subcooling) control
3. Liquid pipe temperature control (with all ports connected and all rooms being air-conditioned)
4. Liquid pipe temperature control for stopped rooms
5. Dew prevention control for indoor rotor
Open Control
1. Outdoor electronic expansion valve control when starting operation
2. Outdoor electronic expansion valve control when the frequency changes
3. Outdoor electronic expansion valve control for defrosting
4. Outdoor electronic expansion valve control for oil recovery
5. Outdoor electronic expansion valve control when a discharge pipe temperature is abnormally
6. Outdoor electronic expansion valve control when the discharge pipe thermistor is disconnected
7. Outdoor electronic expansion valve control for indoor unit freeze-up protection
Feedback Control
1. Target discharge pipe temperature control
63
A
Highest indoor
heat exchanger
temperature
among
operating rooms
A
B
C
high
Dropping zone
Reset zone
Keep
zone
18 class 24/32 class
140°F (60°C) 134.6°F (57°C)
138.2°F (59°C) 132.8°F (56°C)
132.8°F (56°C) 127.4°F (53°C)
SiUS12-928_B
B
C
(R14587)
Function and Control