Refrigerant piping, Connection of refrigerant pipe, Airtight test/air purge, etc – Toshiba MMU-AP0071MH User Manual

Page 16: Requirement, Heat insulating process

Advertising
background image

13

Set notching upward.

Main unit

Pipe side
(Required at the site)

Attached heat insulating pipe

Work using double spanner

• Projection margin in flaring :

B (Unit : mm)

Rigid (Clutch type)

Imperial (Wing nut type)

Connection of refrigerant pipe

Connect all the refrigerant pipes with the flare
connection method

• As the unit is sealed to atmospheric pressure.

It is not abnormal that no “Push....” sound will be
heard upon the removal of the flare nut.

• Ensure use of two spanners for the connecting of the

pipework to the indoor unit.

• Refer to the following table for tightening torque.

Airtight test/Air purge, etc.

For carrying out airtight test, air purge, gas leak check
and addition of refrigerant refer to the Installation
Manual supplied with the outdoor unit.

Open fully valves of the outdoor unit

Gas leak check

Using a leak detector or soapy water, check for gas
leaks at the connecting pipework and the caps on the
service valves.

REQUIREMENT

Use a leak detector designed specifically for HFC
refrigerant (R410A, R134a, etc.).

Heat insulating process

Fit heat insulation to the gas and liquid pipes
separately.

During cooling mode, the temperature of the liquid and
the gas pipes are reduced. Therefore ensure sufficient
insulation is fitted to prevent dew condensation.

• On the gas side ensure that the heat insulation used

is heat resistant to a minimum temperature of 120°C

• Using the supplied heat insulation. Insulate the

interconnecting parts of the indoor unit, ensuring that
there is no exposure of any refrigerant pipework.
As detailed in the below illustration.

REQUIREMENT

Apply the thermal 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.)

5

REFRIGERANT PIPING

B

Connecting pipe

outer dia. (mm)

Ш6.4

Ш9.5

Ш12.7

Ш15.9

Tightening torque

(N•m)

14 to 18

(1.4 to 1.8 kgf•m)

33 to 42

(3.3 to 4.2 kgf•m)

50 to 62

(5.0 to 6.2 kgf•m)

68 to 82

(6.8 to 8.2 kgf•m)

Re-tightening

torque (N•m)

18

(1.8 kgf•m)

42

(4.2 kgf•m)

50

(5.0 kgf•m)

68

(6.8 kgf•m)

Outer diam. of

copper pipe

6.4

9.5

12.7

15.9

R410A tool used

R410A

R22

0 to 0.5 (Same as left)

0 to 0.5 (Same as left)

0 to 0.5 (Same as left)

0 to 0.5 (Same as left)

Conventional tool used

R410A

R22

1.0 to 1.5

0.5 to 1.0

1.0 to 1.5

0.5 to 1.0

1.0 to 1.5

0.5 to 1.0

1.0 to 1.5

0.5 to 1.0

Outer diam. of copper pipe

6.4

9.5

12.7

15.9

R410A

R22

1.5 to 2.0

1.0 to 1.5

1.5 to 2.0

1.0 to 1.5

2.0 to 2.5

1.5 to 2.0

2.0 to 2.5

1.5 to 2.0

Advertising