Note: Temperature sensors for the Midea board are 10K @ 77F / 25C (NTC)
230-volt board shown as an example
Ref # |
Port code |
Content |
Port voltage |
1 |
CN42 |
DC outdoor fan drive port |
5V DC |
2 |
CN6 |
Filter board relay drive port |
12V DC |
3 |
CN12 |
Fan protection output port |
12V DC |
4 |
CN3 |
Power input of main board |
208~230V AC between L1,L2 and L3 |
5 |
CN17 |
Power input of induced draft blower |
208~230V AC |
6 |
CN4 |
Power input of transformer |
208~230V AC |
7 |
CN20 |
CCH-A port |
208~230V AC |
8 |
CN21 |
CCH-B port |
208~230V AC |
9 |
CN1 |
Outdoor fan in A system drive port |
208~230V AC |
10 |
CN11 |
Outdoor fan in B system drive port |
208~230V AC |
11 |
CN34 |
VFD drive port |
5V DC |
12 |
CN29 |
Outdoor fan in A and B system drive port |
24V AC |
13 |
CN24 |
Compressor, indoor fan drive port |
24V AC |
14 |
CN26 |
Electric auxiliary heater or 4-way-A valve port |
24V AC |
15 |
CN27 |
4-way-B valve port |
24V AC |
16 |
CN13 |
High pressure in A and B system |
12V DC |
17 |
CN16 |
Power output of transformer |
24V AC |
18 |
CN43 |
E-stop port |
24V AC |
19 |
CN32 |
R port |
24V AC |
20 |
CN33 |
C port |
0V AC |
21 |
CN9 |
Gas control board drive port |
24V AC |
22 |
CN25 |
24V wire controller power port |
24V AC |
23 |
CN19 |
24V wire controller drive port |
24V AC |
24 |
CN18,CN37 |
Economizer port |
24V AC |
25 |
CN35,CN36 |
OCCUPANCY port |
24V AC |
26 |
CN31,CN7 |
Extern protection port |
12V DC |
27 |
CN28,CN30 |
Extern protection port |
12V DC |
28 |
CN15 |
Reserved |
/ |
29 |
CN39 |
Reserved |
/ |
30 |
CN8 |
low pressure or compressor discharge temperature in A and B system |
5VDC |
31 |
CN40 |
Indoor pipe temperature sensor of A system(T2-A) connection and Indoor room temperature sensor(T1) connection |
0-5V DC (varying) |
32 |
CN5 |
Outdoor temperature sensor(T4) connection |
0-5V DC (varying) |
33 |
CN41 |
Indoor pipe temperature sensor of B system connection |
0-5V DC (varying) |
WARNING:
Information in this article is intended for use by individuals possessing adequate backgrounds of electrical and mechanical experience and who comply with all federal, state, and local laws, rules, orders, or regulations related to the installation, service, or repair of a heating or central air conditioning product. Any attempt to install, service, or repair a heating or central air conditioning product may result in personal injury and/or property damage. The manufacturer or seller cannot be responsible for the interpretation of the information contained herein, nor can it assume any liability in connection with its use.