Midea MHC-V12W/D2N8-B - Page 38

M thermal Mono
36 200204
Midea M thermal Mono Service Manual
Table 4-2.1: Main PCB for hydronic system
Label in Figure
4-2.1
Code
Content
1
CN21
Port for power supply
2
S3
Rotary dip switch
3
DIS1
Digital display
4
CN5
Port for ground
5
CN28
Port for internal pump
6
CN25
Port for IC programming
7
S1,S2,S4
Dip switch
8
CN4
Port for USB
9
CN8
Flow switch
10
CN6
Port for temp. sensors (T2,T2B,TW_out,TW_in, T1,)
11
CN24
Port for temp. sensor(Tbt1, The balanced water tank of up temp. sensor)
12
CN16
Port for temp. sensor(Tbt2, The balanced water tank of up temp. sensor)
13
CN13
Port for temp. sensor(T5, domestic hot water tank temp. sensor)
14
CN15
Port for temp. sensor(Tw2, The outlet water for zone 2 temp. sensor)
15
CN18
Port for temp. sensor(Tsolar, Solar panel temp. sensor)
16
CN17
Port for internal pump
17
CN31
Control port for room thermostat (heating mode)(HT)/Control port for room thermostat (cooling
mode)(CL)/Power port for room thermostat(COM)
18
CN35
Port for smart grid (grid signal, photovoltaic signal)
19
CN36
Port for remote switch, temperature board
20
CN19
Communicate port between indoor unit and outdoor unit
21
CN14
Port for communication with the wired controller
22
CN30
Communicate port between indoor unit and outdoor unit, port for communication with the wired
controller, internal machine parallel
23
CN7
Port for antifreeze E-heating tape(external), additional heat source, compressor run/defrost run
24
CN11
Control port for tank booster heater, internal backup heater 1, input port for solar energy, Port for room
thermostat, SV1(3-way valve), SV2(3-way valve), SV3(3-way valve), zone 2 pump, outside circulation
pump, solar energy pump, DHW pipe pump,
25
CN2
Feedback port for external temp. switch(shorted in default)
26
CN1
Feedback port for temperature switch
27
CN22
Control port for backup heater/booster heater
28
CN41
Port for anti-freeze electric heating tape
29
CN42
Port for anti-freeze electric heating tape
30
CN29
Port for anti-freeze electric heating tape
31
IC39
EEPROM
Midea CAC Confidential