Outline Of Control; Outdoor Unit - Panasonic Urban Multi MX1R Series Service Manual

PACD011001C2

3. Outline of Control

3.1

Outdoor Unit

3.1.1 Compressor PI Control
Controls the compressor to maintain Te at constant during cooling operation and Te at constant during
heating operation to ensure stable compressor performance.
[Cooling operation]
Controls compressor capacity to adjust Te to achieve target value (TeS).
Te setting
Te: Low pressure equivalent saturation temperature (°C)
TeS: Target Te value
(Varies depending on Te setting, operating frequency, etc.)
[Heating operation]
Controls compressor capacity to adjust Tc to achieve target value (TcS)
Tc setting
Tc: High pressure equivalent saturation temperature (°C)
TcS: Target Tc value
(Varies depending on Tc setting, operating frequency, etc.)
3.1.2 Motorized Valve PI Control
Controls the motorized valves (EV1, EV2, EV3) to maintain the outlet superheated degree (SH) of the
outdoor heat exchanger (evaporator) at constant during heating operation.
SH = Th6 – Te
Te: Low pressure equivalent saturation temperature (°C)
Th6: Accumulator outlet temperature (°C)
Superheated degree target value (SHS)
„ Initial value at the start of motorized valve control: SHS = 5 °C
„ When Th6 – Te < 5: SHS (new) = SHS (current) + 1
„ When Th6 – Te > 10: SHS (new) = SHS (current) – 1
DSHi: Inverter discharge pipe superheat
Function UM Combination "MA1R Series" Using R-407C
M
L
(factory setting)
4.5 7.5
M
L
(factory setting)
45 48
However, when Th6 – Te < 5 and DSHi < 30: SHS = 7 °C (fixed)
H
10.5
H
51

Outline of Control

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