Mitsubishi Heavy Industries SRK25GZ-L1 Handbook page 720

V MULTI
(b) Piping work
Request
¡ Use the pipe made of following material. Moreover, it is very convenient for you to use the separately sold piping kit.
Material: Phosphor deoxidized seamless copper tube (C1220T, JIS H3300)
¡ In the case of this unit, condensation water is also generated on the liquid piping. Insulate both of the liquid piping and gas
piping perfectly.
¡ In the case of heat pump type unit, the maximum temperature of the gas piping reaches approx. 120˚C, therefore use the
insulation material which has sufficient heat resistance.
¡ When bending the pipe, bend it with large radius as much as possible. Do not bend the same portion of pipe repeatedly.
¡ Do not let dust, chips or water enter the pipe while pipe working.
¡ The flared connection for refrigerant piping is required. Flare the pipe after inserting
the flared nut into the pipe.
¡ Tighten the flared connection firmly using 2 of spanners. Comply with the following
value for tightening torque of the flared nut.
ø 6.35: 16 to 20 (N·m),
(1.6 to 2.0 (kg·m))
¡ In the case of brazing connection, perform brazing while flowing nitrogen gas in the pipe to prevent generation of oxide film
inside the pipe without fail.
1) How to remove the service panel (Only case of FDC508HES3)
Remove screws on the service panel, pull down the panel toward
the arrow direction, and then remove the panel toward you.
2) Refrigerant pipe connection
a) The piping can be taken out to the right, left (FDC808, 1008 type)
front, rear and botton directions.
b) Cut the plate at the knockout portion on the piping penetration section
with necessary minimum size.
c) Mount the attached edging by cutting it to the appropriate length before connecting the pipe.
Model
Front side connection
¡ Take care so that the piping to be worked does not contact the parts contained in the unit.
IMPORTANT
If it contacts the inner parts, abnormal sound or vibration may occur.
(c) Leak test and air purge
Perform the procedure according to the following instructions.
¡ Perform the air purge of Indoor unit and refrigerant piping by vacuuming method without fail.
Request
Model FDC508HES3
Leak test
1) After tightening all flared nuts on the Indoor
unit and Outdoor unit, hold the service valves
(both of liquid and gas sides) of the Outdoor
unit in fully closed position and perform the
leak test from the charge port of service valve
to confirm that there is no leakage.
(
Use nitrogen gas for leak test. Execute
the test at the pressure of 3.0 MPa
(30kgf/cm G).
2
Hexagonal Head Wrench
(Size 4)
Open
718
Liquid service valve
ø 9.52, ø 12.7: 40 to 50 (N·m),
(4 to 5 (kg·m))
FDC508HES3
Rear side connection
Right side connection
Down side connection
Air purge
2) While holding the service
valves (both of liquid and gas
sides) of the Outdoor unit at
fully closed position, per-
form vacuuming at –0.1 MPa
(–76 cmHg) or under from
)
the service valve charge port.
ø 15.88: 90 to 120 (N·m), ø 19.05: 100 to 140 (N·m),
(9 to 12 (kg·m))
Models FDC808HES3, 1008HES3
Electric wires
{
Left
Liquid and
connection
gas piping
Electric wires
{
Front
Liquid and gas
connection
piping
3) After completion of vacuuming,
Handle
Pin
Gas service valve
(10 to 14 (kg·m))
Internal hook
Liquid piping Back
}
connection
Gas piping
Electric wires Right
}
Liquid gas piping
connection
Botton
connection
remove the cap nut for the valve
stem and fully open the service
valve (for both of liquid and gas)
as shown in the right illustration.
After confirming that the valve is
fully open, tighten the cap nuts (for
valve stem and charge port).
Open state