Use the tightening torque levels as listed in the
following table.
Outer dia. of
Tightening torque
connecting pipe
(ft•lbs (N•m))
(inch (mm))
1/4" (6.4)
10.1 to 13.0 (14 to 18)
3/8" (9.5)
24.6 to 30.4 (34 to 42)
Tightening torque of flare pipe connections.
Pressure of R410A is higher than that of R22.
(Approx. 1.6 times) Therefore, using a torque
wrench, tighten the flare pipe connecting sections
which connect the indoor and outdoor units of the
specified tightening torque.
Incorrect connections may cause not only a gas
leak, but also an issue with the refrigeration cycle.
CAUTION
Tightening with an excessive torque may crack the
nut depending on installation conditions.
Piping with outdoor unit
Shape of valve differs according to the outdoor unit.
For details of installation, refer to the Installation
Manual of the outdoor unit.
25-EN
Airtight test / Air purge, etc.
For airtight test, air purge, addition of refrigerant,
and gas leak check, refer to the Installation Manual
attached to the outdoor unit.
REQUIREMENT
Do not supply power to the indoor unit until the
airtight test and vacuuming are completed.
(If the indoor unit is powered on, the pulse motor
valve is fully closed, which extends the time for
vacuuming.)
Open the valve fully
Open the valve of the outdoor unit fully.
For details, refer to the Installation Manual attached to
the outdoor unit.
Heat insulation process
Apply heat insulation for the pipes separately at liquid
side and gas side.
For the heat insulation to the pipes at gas side,
be sure to use the material with heat-resisting
temperature 248°F (120°C) or higher.
Using the attached heat insulation material, apply the
heat insulation to the pipe connecting section of the
indoor unit securely without gap.
REQUIREMENT
Apply the heat insulation to the pipe connecting
section of the indoor unit securely up to the root
without exposure of the pipe. (The pipe exposed
to the outside causes water leak.)
Wrap heat insulator with its slits facing up (ceiling
side).
Wrap the pipe with the attached heat
insulator without any gap between the
indoor unit.
The seam must be faced upward
Indoor unit
(ceiling side).
Flare nut
Heat insulator
of the pipe
Heat insulation
Banding band
pipe (Accessory)
(Locally procured)
Union
– 13 –
7
Electrical connection
WARNING
1. Use predefined wire and connect them
certainly.
Keep the connecting terminal free from
external force.
Improper wire connection or clamping may result
in exothermic, fire or malfunction.
2. Connect ground wire. (grounding work)
Incomplete grounding cause an electric shock.
Do not connect ground wires to gas pipes, water
pipes, lightning rods or ground wires for telephone
wires.
3. Install appliance in accordance with national
wiring regulations.
Capacity shortage of circuit breaker or incomplete
installation may cause an electric shock or a fire.
CAUTION
Consult local building codes, NEC (National
Electrical Code) or CEC (Canadian Electrical
Code) for special requirements.
If incorrect / incomplete wiring is carried out, it will
cause an electrical fire or smoke.
Install circuit breaker is not tripped by shock
waves.
If circuit breaker is not installed, an electric shock
may be caused.
Use the cord clamps attached to the product.
Do not damage or scratch the conductive core and
inner insulator of power and control wires when
peeling them.
Use the power cord and control wire of specified
thickness, type, and protective devices required.
Do not connect 208/230V power to the terminal
blocks (U1, U2, A, B etc.) for control wiring.
(Otherwise, the system will fail.)
Perform the electric wiring so that it does not come
to contact with the high-temperature part of the
pipe.
The coating may melt resulting in an accident.
Do not turn on the circuit breaker of the indoor unit
until vacuuming of the refrigerant pipes completes.
REQUIREMENT
For power supply wiring, strictly conform to the
Local Regulation in each country.
Run the refrigerant piping line and control wiring
line in the same line.
Power supply wire and
control wires specifications
Power supply wire and control wires are locally
procured.
For the power supply specifications, follow the table
below. Low capacities should be avoided due to the
risk of overheating or burnout.
Indoor unit power supply
For the power supply of the indoor unit, prepare the
exclusive power supply separately from that of the
outdoor unit.
q Power supply
Power supply
208/230-1-60
Control wiring, Central control wiring
2-core with non-polarity wires are used for the
control wiring between indoor unit and outdoor unit
and Central control wiring.
To prevent noise trouble, use 2-core shielded wire.
The length of the communication line means the
total length of the control wire length between indoor
and outdoor units added with the central control wire
length.
26-EN