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.
<Operation Sound>
<Switching Procedure to Noise Reducing Control>
(1) Remove the 3 screws fixing the inspection panel and remove the inspection panel. (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)
When this function is used, the cooling ability is slightly degraded. Therefore,
when this function is to be enabled, make sure to receive the approval of the client.
1. In the test operation, high-power operation, defrost operation or low ambient cooling
operation (to be cancelled at the outside temperature of 57 °F(14 °C) or less, or 63 °F(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 500rpm.
Also, the maximum frequency (Hz) is controlled in the cooling (30Hz) or heating
operation (30Hz).
<In Cooling Operation>
Specifications
Cooling Cooling
55 dB-A 47 dB-A
Noise Reducing Control
(Fan's motor speed : 500rpm)
Normal Operation
Normal Operation or
Noise Reducing Operation is kept.
(Initial setting is the normal operation.)
Noise Reducing Operation
Outdoor Air Temp. °F(°C)
91(33)
82(28)

Noise Reducing Control (Outdoor Unit)

Fig.2 View from front
Fig.3 Control P.C.Board
SW01
Dip switch (SW01)
ON
12
Power lamp
NOTE
NOTE
Control P.C.Board
Inspection panel
Slide downward
33