Installation Guide

Page 16mrcool.com
Indoor Unit Installation
Step 6: Connect signal cable
A signal cable enables communication between the
indoor and outdoor units and provides power to the
indoor unit. The tables below are for reference.
NOTE: the rated amp (A) draw will be at the
condenser (outdoor unit) and a table is provided in
that section, showing the required power cable gauge
specific to each.
Minimum Cross-Sectional Area of
Power and Signal Cables
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.
Rated Current of
Appliance (A)
Nominal Cross-Sectional
Area (mm²)
> 3 and ≤ 6
> 6 and ≤ 10
> 10 and ≤ 16
> 16 and ≤ 25
> 25 and ≤ 32
> 32 and ≤ 40
0.75
1
1.5
2.5
4
6
Other Regions
North America
10 18
13 16
18 14
25 12
30 10
Appliance Amps (A) AWG
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.
1. Prepare the cable for connection:
a. Using wire strippers, strip the rubber
jacket from both ends of signal cable to
reveal about 1.57in (40mm) of the wires
inside.
b. Strip the insulation from the ends of the wires.
c. Using wire crimper, crimp u-type lugs on the
ends of the wires.
PAY ATTENTION TO LIVE WIRE
While crimping wires, make sure you clearly
distinguish the Live (“L”) Wire from other wires.
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. 3.9A on previous page for wiring diagram.
Wiring diagram also found inside lid of interior unit