Troubleshooting Guide

Table Of Contents
MRCOOL Universal Service Manual
19
Outdoor unit:
Model: MDUO18036MDUO18060
Mainboard
No.
Printing
Interface
No.
Printing
Interface
1
AC-L
Live wire input
11
H-PRESS
high pressure sensor
interface
2
AC-N
Neutral wire input
12
LPP
System low pressure
protection interface
3
HEAT_TI
E_B
Chassis electric
heating belt
13
HPP
System high pressure
protection interface
4
HEAT_TI
E_C
Compressor electric
heating belt
14
T_SENSOR2
2. Outdoor tube temperature
sensor interface
4. Outdoor ambient
temperature sensor interface
6. Discharge temperature
sensor interface
5
4WAY
4-way valve
15
T_LAC
Low temperature cooling
temperature sensing