Panasonic U-72MF2U9 Service Manual page 18

3. Compressor Control
Compressor Control Table
1
2
Evaporation temperature (Te) and condensation temperature (Tc) areas A, B, C and D are the same as for
evaporation temperature control and condensation temperature control.
(2) Increasing/decreasing the heat exchanger capacity (when the outdoor unit heat exchanger is functioning as a
condenser)
• Primarily when both the evaporation temperature (Te) and condensation temperature (Tc) are high
This occurs when the cooling capacity (heat intake) is low and the heating capacity (heat discharge) is high.
3
The outdoor heat exchanger capacity is increased, increasing the system condensation capacity and lowering
the condensation temperature (Tc). The amount of heat discharge at the outdoor unit heat exchanger is
increased, increasing the heat intake at the cooling mode indoor units and lowering the evaporation
temperature (Te).
• Primarily when both the evaporation temperature (Te) and condensation temperature (Tc) are low
4
This occurs when the cooling capacity (heat intake) is high and the heating capacity (heat discharge) is low.
The outdoor heat exchanger capacity is decreased, decreasing the system condensation capacity and raising
the condensation temperature (Tc). The amount of heat discharge at the outdoor unit heat exchanger is
decreased, decreasing the heat intake at the cooling mode indoor units and raising the evaporation
temperature (Te).
5
Outdoor Unit Heat Exchanger Control Table (when the outdoor unit heat exchanger is functioning as a
condenser)
6
A
7
42.8°F (6°C)
B
37.4°F (3°C)
32°F (0°C)
8
C
26.6°F (-3°C)
9
Low Condensation Temp. [Tc]
A
A UP
B slow_UP
C not_UP
Low ←
A
STAY
DOWN
B
not_UP
Target
DOWN
Condensation Temp. [Tc]
B
Target
1 - 10
3WAY VRF SYSTEM
Control Functions
High
C D
STOP
→ High
D
C
UP