Operation Control; Cooling Operation - Panasonic CU-3E19RBU-5 Service Manual

11. Operation Control

11.1 Cooling Operation

11.1.1 Outdoor fan control

When cooling operation is enabled, based on outdoor ambient temperature, fan motor control will be adjusted
according to figure below:
11.1.2 Annual Cooling control

This control is to enable cooling operation when outdoor ambient temperature is low.

Control start conditions:
Cooling operation is activated with compressor ON.
o
Outdoor ambient temperature is less than 59°F (15°C).
o

Control contents:
When the above conditions are fulfilled, based on outdoor pipe temperature, the outdoor fan motor will
o
operate according to figure below:

To improve the judgment accuracy during annual cooling control, outdoor ambient temperature sampling for
2 minutes will be activated every 35 minutes under designated fan speed.

Control stop conditions:
When either one of the start conditions are not complied.
o
11.1.3 Cooling Powerful Operation 1

During cooling operation, this control is to concentrate outdoor unit capability to the powerful operation enabled
indoor unit by temporary stop the capability supply to low load demand indoor units.

Operation start condition:
Powerful operation ON for targeted indoor unit.
o

Operation content:
If other indoor units (where Powerful operation are OFF) achieve setting temperature continuously for
o
1 minute after received powerful command from indoor unit, then capability supply to other indoor units are
stopped for minimum 3 minutes.
Capability supply stop period follows powerful operation period.

Operation stops when comply either one of the following conditions:
When other indoor units (where Powerful operation are OFF) is demand for capacity.
o
When the powerful operation is OFF for all indoor units.
o
When Quiet operation received from 1 indoor unit.
o
When protection control starts.
o
RPM free
59.0°F (15°C)
RPM controlled
8.6°F (-13°C)
Stopped
OD temp.
RPM up
93.2°F (34°C)
RPM unchanged
75.2°F (24°C)
RPM down
66.2°F (19°C)
Stopped
OD Pipe temp.
51
55.4°F (13°C)
91.4°F (33°C)
73.4°F (23°C)
64.4°F (18°C)