Air Handler Installation 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

To a contact to control compressor

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

24 Volt Emergency (hot)

24 Volt (Common)

To a AC contact to control the indoor unit fan

Thermostat