Service manual

44
11
Outline of Control
Outdoor Units
Item Operation explanation and applied data, etc. Remarks
9. Compressor
winding
heating control
This control is to prevent stagnation of refrigerant in
the compressor case by a supply of current to heat the
windings while the inverter compressor is off. This
control is executed by the inverter outdoor unit only. If
the supply of current is not turned on for a specified
time before trial operation, when installation work has
finished, a fault of the compressor may occur. If the
power source is interrupted for a period of time it is
necessary to switch power to the system for a minimum
of 24 hours before commencing system operation
(1) Control conditions
Compressor stops and TD<35°C.
(2) Contents of control
This control is executed by temperature detected by
TK3 sensor as shown in the following figure.
NOTE:
Switching may be heard during heat winding
operation, but it is not an error/fault.
10. Crank case
heater control
This control is executed by the fixed-speed unit only.
(1) Control contents
• This control is switched off when TK3 sensor
detected 40°C or higher temperature, and
switched on when TK3 sensor detected 35°C or
lower temperature.
• After the compressor status changed from OFF to
ON, ON status continues for 10 minutes.
A zone B zone C zone
Intermittent
Continuous switch-on power No
switch-on power ON: 10 minutes switch-on power
OFF: 5 minutes
TK3
40°C
34°C
25°C
C zone
B zone
A zone