Installation Manual and Owner's Guide
Cover
Outdoor Unit 
Wiring Diagram 
is located on 
the inside of the 
wire cover on 
the outdoor unit.
Fig. 8.2
Page 34
mrcool.com
Electrical Connections
Appliance
Amps(A)
AWG
35
45
8
6
27K
36K
Model Series
Minimum Wire Gauge
 for Power Cables
USE THE RIGHT CABLE 
• See table below for gauge requirements
ALL WIRING MUST BE PERFORMED STRICTLY
IN ACCORDANCE WITH THE WIRING 
DIAGRAM LOCATED AS SHOWN IN FIG 8.2.
1. Unscrew the electrical wiring cover and remove it.
2. Unscrew the cable clamp below the terminal block 
and place it to the side.
3. Match the wire colors / labels with the labels on 
the terminal block, and firmly screw the u-lug of each 
wire to its corresponding terminal.
4.  After checking to make sure every connection is 
secure, loop the wires around to prevent rain water 
from flowing into the terminal. 
5. Using the cable clamp, fasten the cable to the 
unit. Screw the cable clamp down tightly.
6. Insulate unused wires with PVC electrical tape. 
Arrange them so that they do not touch any electrical 
or metal parts.
7.  Replace the wire cover on the side of the unit, and 
screw it in place.
The air conditioner’s circuit board (PCB) is 
designed with a fuse to provide overcurrent 
protection. The specifications of the fuse are 
printed on the circuit board.
EXAMPLE Indoor unit: T3.15AL/250VAC, 
T5AL/250VAC, T3.15A/250VAC, T5A/250VAC, etc. 
EXAMPLE Outdoor unit: 
T20A/250VAC(<=18000Btu/h units), 
T30A/250VAC(>18000Btu/h units), etc. 
 NOTE ABOUT FUSE SPECIFICATIONS
Connect signal and power cables
The outside unit’s terminal block is protected by an 
electrical wiring cover on the side of the unit. A com-
prehensive wiring diagram is printed on the inside of 
the wiring cover.










