Hitachi SET FREE MINI SERIE Manual De Instrucciones página 19

REFRIGERANT PIPING & REFRIGERANT CHARGE
6 Mount the piping cover in order to avoid water entering into
the unit. Seal the holes where pipes and wires are inserted,
by using a insulator and rubber bushes as shown below.
Rubber bush (Accessory)
Add cross cutting to the center of the rubber bushing.
Attach rubber bushing to the hole of wiring.
In case that conduit tube is used, rubber bush is not
Piping
necessary.
cover
Gas pipe
Power source and operating wiring
Liquid pipe
Insulation (Accessory).
Attach insulation to the pipe as shown in the figure and space shall not
exist at the piping hole.
Cut the insulation as shown in the figure when attaching work is difficult.
7 If the field-supplied piping is connected with stop valves
directly, it is recommended use a tube bender.
8 Check to ensure that the stop valves are closed completely
before connecting pipes.
9 Connect the field supplied refrigerant pipes to the indoor unit
and outdoor unit. Apply the oil thinly at the seat flare nut and
pipe before tightening.
10 After connecting the refrigerant piping, seal the open space
between knockout hole and refrigerant pipes by using
insulation material. Operation of stop valve should be
performed according to the figure below.
Closed upon factory shipping
8.3 BRAZING WORK
!
C A U T I O N
• Use nitrogen gas for blowing during pipe brazing. If oxygen, acetylene
or fluorocarbon gas is used, it will cause an explosion or poisonous
gas.
9 PMML0389B rev.1 - 07/2016
Nº Description
Cap

Allen wrench Fig.A: Hex 4 mm / Fig.B: Hex. 5 mm

Refrigerant Piping Field Supplied

Flare nut

Refrigerant pressure To Outdoor Unit

Seat Surface Fully closed position

Check Joint Only the charging hose can be connected

Cap

O-Ring Rubber

Open – Counterclockwise
Spindle valve

Close – Clockwise
Tightening Torque (Nm)
Valve type Model
Fig.A Liquid valve (4~6)HP
Fig.B Gas valve (4~6)HP

Outdoor unit stop valve
Do not apply two spanners
at this position. If applied,
leakage will occur.
Use two spanners
here for pipe
connection
Do not work with
two spanners
here.
Refrigerant
leakage shall
occur
Spindle type
!
C A U T I O N
• At the test run, fully open the spindle.
• If not fully opened, the devices will be damaged.
• Do not attempt to turn service valve rod beyond its stop.
• Do not loosen the stop ring. If the stop ring is loosened, it is dangerous
since the spindle will hop out.
• An excess or a shortage of refrigerant is the main cause of trouble
to the units. Charge the correct refrigerant quantity according to the
description of label at the inside of service cover.
• Check for refrigerant leakage in detail. If a large refrigerant leakage
occurs, it will cause difficulty with breathing or harmful gases would
occur if a fire was being used in the room.
• A lot of oxidation film will occur inside of tubes if no nitrogen gas
blowing is performed during brazing work. This film will be flecked
off after operation and will circulate in the cycle, resulting in clogged
expansion valves, etc. This will cause bad influence to the compressor.
• Use a reducer valve when nitrogen gas blowing is performed during
brazing. The gas pressure should be maintained within 0.03 to 0.05
MPa. If a excessively high pressure is applied to a pipe, it will cause
an explosion.
Remarks
A B C D
7-9 33-42 33-42 14-18
9-11 30 60 9
Stop valve
Flare nut
Don not apply two
spanners work here
Position to apply
spanners
Ball type