Mitsubishi Electric City Multi PQHY-P72 Service Handbook page 31

[ II Restrictions ]
SW4-7:OFF (Compressor ON/OFF, NIGHT MODE)
CN3D 1-3P
Open
Short-circuit
SW4-7:ON (STEP DEMAND)
CN3D 1-3P
Note the following steps to be taken when using the STEP DEMAND
(Example) When switching from 100% to 50%
Demand control
steps
If the step listed as the wrong example above is taken, thermo may go off.
The percentage of the demand listed in the table above is an approximate value based on the
compressor volume and does not necessarily correspond with the capacity.
Example of wiring connection
CN51
Remote controller board
Relay circuit
X
L
1
Y
L
2
Field-installed
L1 : Error indicator lamp/freeze prevention output
L2 : Compressor operation display lamp
X,Y : Relay (For 12V DC coil rating 0.9 W or below)
CN3D
Relay circuit
Remote controller board
SW1
X
SW2
Y
Field-installed
SW1 : NIGHT MODE command or Compressor ON/OFF
SW2 : Compressor ON/OFF command
X,Y : Relay (Rated contact DC 15 V 0.1 A or above
Minimum applied load 1 mA or below)
Compressor ON/OFF
OFF
ON
Open
Short-circuit
(Wrong) 100%
(Correct) 100%
Controller board on
outdoor (heat source) unit
5
X
CN51
4
Y
3
Maximum allowable wiring length = 10 m
Controller board on
outdoor (heat source) unit
1
X CN3D
2
Y
3
Maximum allowable wiring length = 10 m
CN3D 1-2P
Open
Short-circuit
CN3D 1-2P
Open
100% (not on the
on-DEMAND control)
0%
0% 50%
75% 50%
- 22 -
NIGHT MODE
OFF
ON
Short-circuit
75%
50%