Installation Manual
Page 15 mrcool.com
Indoor Unit Installation
BEFORE PERFORMING ANY ELECTRICAL WORK, TURN OFF ALL POWER TO THE SYSTEM.
 BEFORE PERFORMING ELECTRICAL WORK, READ THESE REGULATIONS 
1. All wiring must comply with local and national electrical codes, and must be installed by a 
 licensed electrician.
2. All electrical connections must be made according to the Electrical Connection Diagram located 
 on the panels of the indoor and outdoor units.
3. If there is a serious safety issue with the power supply, stop work immediately. Explain your 
 reasoning to the client, and refuse to install the unit until the safety issue is properly resolved.
4. Power voltage should be within 90-110% of rated voltage. Insufficient power supply can cause a 
 malfunction, electrical shock, or fire.
5. Circuit, including any switches, should have a capacity 1.5 times the maximum unit 
 current (amps).
6. If connecting power to fixed wiring, the qualified technician must use an approved circuit 
 breaker or switch that disconnects all poles and has a contact separation of at least 
 1/8 in (3 mm). It must be incorporated into the fixed wiring.
7. Make sure to properly ground the air conditioner.
8. Every wire must be firmly connected. Loose wiring can cause the terminal to overheat, 
 resulting in malfunction and possible fire.
9. If the unit has an auxiliary electric heater, it must be installed at least 40 in (1 meter) away 
 from any combustible materials.
10. To avoid getting an electric shock, never touch the electrical components soon after the power
 supply has been turned off. Always wait 10 minutes or more before touching the electrical 
 components once the power has been turned off.
11. If connecting power to fixed wiring, a surge protector and main power switch should be installed.
 DO NOT connect another appliance to the same circuit. Only connect the unit to an individual 
 branch circuit outlet.
 DO NOT let wires touch or rest against refrigerant tubing, the compressor, or any moving parts 
 within the unit.
Fig. 4.7a










