Installation Manual
Page 16mrcool.com
Indoor Unit Installation
Step 6: Connect signal cable
TAKE NOTE OF FUSE SPECIFICATIONS
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, such as: 
T3.15A/250VAC, T5A/250VAC, etc.
CHOOSE THE APPROPRIATE CABLE SIZE
The size of the power supply cable, signal 
cable, fuse, and switch needed is determined 
by the maximum unit current. The maximum 
unit current is indicated on the nameplate 
located on the side panel of the unit. Refer 
to this nameplate to choose the right cable, 
fuse, or switch.
NOTE: In North America, please choose the 
right cable size according to the Minimum 
Circuit Ampacity indicated on the nameplate 
of the unit.
1. Prepare the cable for connection:
2.  Open front panel of the indoor unit.
3. Using a screwdriver, open the wire box cover 
 on the right side of the unit. This will reveal the 
 terminal block.
4. Unscrew the cable clamp below the terminal block 
 and place it to the side.
5. Facing the back of the unit, remove the plastic
 panel on the bottom left-hand side.
All wiring must be performed in accordance 
with the wiring diagram Fig. 4.7a shown on 
the previous page. 
Terminal block
Wire cover
Screw
Cable clamp
Fig. 4.7b
See Fig. 4.7A on previous page for wiring diagram.
Wiring diagram also found inside lid of interior unit 
6.  Feed the signal wire (protected by conduit) through
      this slot, from the back of the unit to the front.
7.  Facing the front of the unit, match the wire colors 
 with the labels on the terminal block, connect the 
 u-lug and firmly screw each wire to its 
 corresponding terminal.
DO NOT MIX UP LIVE AND NULL WIRES
This is dangerous, and can cause the air 
conditioning unit to malfunction.
8. After checking to make sure every connection is 
 secure, use the cable clamp to fasten the signal 
 cable to the unit. Screw the cable clamp down 
 tightly.
9.  Replace the wire cover on the front of the unit, and 
 the plastic panel on the back.
THE WIRING CONNECTION PROCESS MAY 
DIFFER SLIGHTLY BETWEEN UNITS AND 
REGIONS. 
North America
Appliance
Amps(A)
3
Model
Series
(Indoor Unit)
MCA MOP
15
All Capacity Wall 
Mounted Air 
Handlers










