Toshiba MMD-AP0071SH-C Service Manual page 42

7
REFRIGERANT PIPING
• Projection margin in flaring :
B (Unit : mm)
Rigid (Clutch type)
R410A tool used Conventional tool used
Outer diam. of
copper pipe
R410A R22 R410A R22
6.4 0 to 0.5 (Same as left) 1.0 to 1.5 0.5 to 1.0
9.5 0 to 0.5 (Same as left) 1.0 to 1.5 0.5 to 1.0
12.7 0 to 0.5 (Same as left) 1.0 to 1.5 0.5 to 1.0
Imperial (Wing nut type)
Outer diam. of copper pipe R410A R22
6.4 1.5 to 2.0 1.0 to 1.5
9.5 1.5 to 2.0 1.0 to 1.5
12.7 2.0 to 2.5 1.5 to 2.0
Connection of refrigerant pipe
Connect all the refrigerant pipes with flare connecting
work.
• Since the atmospheric pressure only is sealed
as the sealing gas, it is not abnormal that
"Pushu..." sound is not heard when the flare
nut is removed.
• Be sure to use a double spanner for pipe
connecting work of the indoor unit.
Work using double spanner
• Refer to the following table for tightening torque.
Connecting pipe Tightening torque Re-tightening
outer dia. (mm) (N•m) torque (N•m)
Ø6.4 14 to18 (1.4 to 1.8 kgf•m) 18 (1.8 kgf•m)
Ø9.5 33 to 42 (3.3 to 4.2 kgf•m) 42 (4.2 kgf•m)
Ø12.7 50 to 62 (5.0 to 6.2 kgf•m) 62 (6.2 kgf•m)
• Tightening torque of flare pipe connections
B
Pressure of R410A is higher than that of R22 by
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 a trouble of the
refrigerating cycle.
REQUIREMENT
If an excessive torque is applied, the nut
may crack depending on the installation
conditions.
Airtight test/Air purge, etc.
For airtight test, air purge, addition of refrigerant, and
gas leak check, follow the Installation Manual attached
to the outdoor unit.
REQUIREMENT
Be sure to use the tool such as charge hose
exclusive to R410A.
Do not turn on the power until the airtight test and
the vacuuming have finished. (If turning on the
power, the incorporated PMV is closed fully and
the period until the vacuuming finishes elongates.
Open fully valves of the outdoor unit
Gas leak check
Check with a leak detector or soap water whether gas
leaks or not, from the pipe connecting section or cap
of the valve.
REQUIREMENT
Use a leak detector manufactured exclusively for
HFC refrigerant (R410A, R134a, etc.).
8
ELECTRIC WORK
1. Using the specified wires, ensure to connect the wires, and fix wires securely so that the
external strength of the wires do not transmit to the connecting part of the terminals.
Incomplete connection or fixation may cause a fire, etc.
2. Be sure to connect earth wire. (Grounding work)
Do not connect the earth wire to gas pipe, city water pipe, lightning rod, or the earth wire of telephone.
Incomplete grounding causes an electric shock.
3. For electric work, strictly follow to the Local Regulation in each country and the Installation
Manual, and use an exclusive circuit.
Capacity shortage of power circuit or incomplete installation may cause an electric shock or a fire.
Be sure to install an earth leakage breaker.
If an earth leakage breaker is not installed, an electric shock may be caused.
REQUIREMENT
• For power supply wiring, strictly conform to the Local Regulation in each country.
• For wiring of power supply of the outdoor units, follow to the Installation Manual of each outdoor unit.
• Never connect 220V power to the terminal blocks (A, B, U1, U2, X, Y, etc.) for control wiring.
(Otherwise, the system will be failed.)
• Perform the electric wiring so that it does not come to contact with the high-temperature part of the pipe.
The coating may melt resulted in an accident.
• After connecting wires to the terminal blocks, provide a trap and fix wires with the wire clamp.
• Store the refrigerant piping line and control wiring line in the same line.
• Do not turn on the power of the indoor unit until vacuuming of the refrigerant pipes completes.
WARNING
CAUTION