Mitsubishi Electric PKA-RP1.6GAL Service Technical Manual page 66

Special function
(a) Low-level sound priority mode (Local wiring)
Unit enters into Low-level sound priority mode by SW7-1, 2 and external signal input setting.
Inputting external signals to the outdoor unit decreases the outdoor unit operation sound 3 to 4 dB lower than that of usual.
Adding a commercial timer or on-off switch contactor setting to the CNDM connector which is optional contactor for Demand
input located on the outdoor controller board enables to control compressor operation frequency. In Low-level sound priority
mode, the maximum outdoor fan steps is regulated to 8 and the maximum operation frequency of the compressor is
regulated to specified range in cool mode. In heating mode, the maximum compressor operation frequency is regulated to
specified range.
W The performance is depends on the load of conditioned air of the room.
How to wiring
<Low-level sound priority mode circuit>
Insulate this point securely as
this is not used.
Purchased at local
Relay
supply
~
SW1
X
SW1 : Switch
X : Relay (Contact spec. : DC1mA)
1) Make the circuit as shown above with Adaptor for external signal input(PAC-SC36NA).
2) Turn SW1 to on for Low-level sound priority mode.
Turn SW1 to off to release Low-level sound priority mode and normal operation.
(b) On demand control (Local wiring)
Demand control is available by external input. In this mode, the outdoor unit stops and indoor unit operates with fan mode.
W The setting of SW-7 is not required for the demand control.
How to wiring
Basically, the wiring is the same.
Connect an SW 1 which is procured at field to the between Orange and Red(1 and 3) of the Adaptor for external signal
input(PAC-SC36NA), and insulate the tip of the brown lead wire.
(c) Refrigerant collecting (pump down)
Perform the following procedures to collect the refrigerant when relocating or replacing the indoor or outdoor units.
1Before collecting the refrigerant, first make sure that the all of the SW5 DIP switches for function changes on the control
board of the outdoor unit are set to OFF. If all of the SW5 switches are not set to OFF, record the settings and then set all of
the switches to OFF. Now, start refrigerant collecting operation. After moving the unit to a new location and completing the
test run, set the SW5 switches to the previously recorded settings.
2Turn on the power supply (circuit breaker).
wWhen power is supplied, make sure that "CENTRALLY CONTROLLED" is not displayed on the remote controller. If
"CENTRALLY CONTROLLED" is displayed, the refrigerant collecting (pump down) cannot be completed normally.
3 Close the liquid stop valve.
4 Set the SWP switch on the outdoor controller board to ON. The compressor (outdoor unit) and ventilators (indoor and
outdoor units) start operating and refrigerant collecting operation begins. LED1 and LED2 on the control board of the
outdoor unit are lit.
wSet the SWP switch (push-button type) to ON in order to perform refrigerant collecting operation only when the unit is
stopped. However, refrigerant collecting operation cannot be performed until compressor stops even if the unit is stopped.
Wait three minutes until compressor stops and set the SWP switch to ON again.
5Because the unit automatically stops after the refrigerant collecting operation is conducted for around 2 to 3 minutes, make
sure to close the gas stop valve immediately. LED1 is not lit and LED2 is lit at this time. If LED1 is lit and LED2 is not lit at
this time, please repeat the procedure from 2.
6Turn off the power supply (circuit breaker.)
Adaptor for external
signal input
(PAC-SC36NA)
X
Max. 10 m including local wiring
<Outdoor unit controller board>
Outdoor unit
controller board
Red
3
Brown
2
Orange
1
CNDM
Pump down
66
<Outdoor unit controller board>
3
CNDM
2
1