Use and Care Manual
Page 22mrcool.com
Unit Installation
WARNING
1.  High and low voltage wires should be led through different rubber rings of the electric box 
cover.
2. Do not bundle the thermostat wires or lay them side by side, otherwise errors will occur.
3.  High and low voltage wires should be secured separately. Secure the former ones with large 
clamps and the latter ones with small clamps.
4.  Use screws to tighten the power cords and thermostat wires of the units on the terminal 
board. Improper connection may create a fire hazard.
5. If the power cords and thermostat wires are not correctly connected, the air conditioner may 
suffer damage.
6. Ground the units by connecting the ground wire. 
7. The units should comply with applicable local and national rules and regulations on power 
consumption.
8. When connecting the power cord, make sure the phase sequence of the power supply 
matches with the corresponding terminals, otherwise the compressor will get reversed and 
operate abnormally.
Electrical Connection
Connecting the Power Cord & Thermostat Wire
Electrical wiring of Single-phase unit: MDUI18048/MDUI18060
Fig. 2.13
Terminals 
Code
Remarks
Y
To a contact to control compressor
B
To a contact to control the 4way valve. It is suitable for
four way valve working in heating mode.
W1 To a contact to control the auxiliary heater 1
R
24 Volt Emergency (hot)
C
24 Volt (Common)
G
To a AC contact to control the indoor unit fan
Thermostat










