Hitachi RAS-3-HVNC - Piping Connection for Outdoor Unit; Ras-(2-2.5)Hvnp; Ras-3 Hvnc

3. Piping work and refrigerant charge
56
SMGB0079 rev.0 - 01/2013
3.2 Piping connection for outdoor unit
3.2.1 RAS-(2-2.5)HVNP / RAS-3HVNC
1 Take the piping cover away from the unit. Then fetch the pipes through the rear side and route piping according to the
installation place as shown in the gure. Make holes by cutting along the guideline at the rear of the cover or punching
with a driver. Remove the burr with a cutter, and place a insulation (eld supplied) to protect cables and pipes.
Pipe cover
Rear side
piping
Stop valve
Direction to remove pipe cover
Connecting
piping
2 Attach the pipe cover in order to prevent rainwater from entering inside the cabinet.
3 Use a pipe bender for pipe bending work when connecting pipes.
4 Check to ensure that the stop valves are completely closed before connecting pipes.
5 Connect the eld supplied refrigerant pipes to the indoor unit and outdoor unit. Apply the oil thinly at the seat are nut
and pipe before tightening.
The required tightening torque is as follows:
Pipe Size Tightening Torque (Nm)
Ø 6.35 mm (1/4) 20
Ø 9.52 mm (3/8) 40
Ø 12.70 mm (1/2) 60
Ø 15.88 mm (5/8) 80
Ø 19.05 mm (3/4) 100
Use two spanners
here for pipe con-
nection
Do not work with
two spanners
here.
Refrigerant
leakage shall
occur
6 After connecting the refrigerant piping, seal the open space between knockout hole and refrigerant pipes by using
insulation material.
Unit Side
Nº Description

Insulation Material

Insulation Material

Field Supplied

Insulation Material
7 Operation of stop valve should be performed according to the Outdoor unit stop valve explanation.