technical & service manual dc inverter multi-system air conditioner

7-3. Special Functions
7-3-1. Noise Reducing Control (Outdoor Unit)
The noise reducing control is the function used for silent operation of the air conditioner by means of
setting the dip switch on the outdoor unit P.C.Board to control the fan and compressor's motor speed.
NOTE
When this function is used, the cooling or heating ability is slightly degraded. Therefore,
when this function is to be enabled, make sure to receive the approval of the client.
Specifications
Noise Reducing Control
(Fan's motor speed : 550rpm)
Cooling Heating Cooling Heating
50 dB-A 53 dB-A 47 dB-A 47 dB-A
Outdoor Air Temp. [°C]
33
28
NOTE
Normal Operation
Normal Operation or
Noise Reducing Operation is kept.
(Initial setting is the normal operation.)
Noise Reducing Operation
1. In the test operation, high-power operation, defrost operation or low ambient cooling
operation (to be cancelled at the outside temperature of 14 °C or less, or 17 °C or
more), the noise reducing control is not available.
2. In the noise reducing operation, the fan's maximum motor speed is limited to 550rpm.
Also, the maximum frequency (Hz) is controlled in the cooling (42Hz) or heating
operation (40Hz).
(1) Remove the 3 screws fixing the right front cover and remove the right front cover. (Fig. 2)
(2) When the switch No. 1 of the dip switch (SW01) on the control P.C.Board is turned ON,
the noise reducing control is enabled. (Fig. 3)
Slide downward
Fig.2 View from front
Outdoor Air Temp. [°C]
15
10
Control P.C.Board
Right front cover
24
Noise Reducing Operation
Normal Operation or
Noise Reducing Operation is kept.
(Initial setting is the normal operation.)
ERR0
ERR1
ERR2
ERR3
Normal Operation
Power lamp
SW01
SW02
Fig.3 Control P.C.Board
SW01
ON
1 2
Dip switch (SW01)