Hitachi UTOPIA RAS-4HVRP2E - Piping Connection for Outdoor Unit; Ras-3 Hvrc2

3 Piping work and refrigerant charge
Piping connection for outdoor unit
SMGB0136 rev.0 - 07/2021
46
3.2 Piping connection for outdoor unit
3.2.1 RAS-3HVRC2
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 connection
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 “3.2.3 Outdoor unit stop valve” explanation.