Mitsubishi Electric EHST20C-VM6HB Service Manual page 64

Special function
(a) Low-level sound priority mode (Local wiring)
By performing the following modification, operation noise of the outdoor unit can be reduced by about 3-4 dB.
The low noise mode will be activated when a commercially available timer or the contact input of an ON/OFF switch is added to
the CNDM connector (option) on the control board of the outdoor unit.
• The ability varies according to the outdoor temperature and conditions, etc.
1 Complete the circuit as shown when using the external input adapter (PAC-SC36NA-E). (Option)
2 SW7-1 (Outdoor unit control board): OFF
3 SW1 ON: Low noise mode
SW1 OFF: Normal operation
A
X
X
F
SW1
B
OCH533D
C D
A Circuit diagram example
CNDM
Orange
(low noise mode)
1
Brown
B On-site arrangement
Red
C External input adapter
3
(PAC-SC36NA-E)
E
X: Relay
D Outdoor unit control board
E Maximum 10 m
F Power supply for relay
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