Air Purge; Additional Refrigerant Charge - Mitsubishi SRK21CNS-S6 Technical Manual

Air purge

①
Tighten all flare nuts in the pipings both indoor and
outside wall so as not to cause leak.
②
Connect operation valve, charge hose, manifold valve
and vacuum pump as is illustrated right.
③
Open manifold valve handle Lo to its full width, and
perform vacuum or evacuation.
Continue the vacuum or evacuation operation for
15 minutes or more and check to see that the vacuum
gauge reads -0.1MPa.
④
After completing vacuum operation, close the Lo handle
and stop operation of the vacuum pump.
⑤
After completing vacuum operation, fully open
operation valve (Both gas and liquid sides) with
hexagon headed wrench.
⑥
Check for possible leakage of gas in the connection
parts of both indoor and outdoor.
•
Since the system uses check joints differing in diameter
from those found on the conventional models, a charge
hose (for R22) presently in use is not applicable. Please
use one designed specifically for R410A.
•
Please use an anti-reverse flow type vacuum pump adapter
so as to prevent vacuum pump oil from running back into
the system. Oil running back into an air-conditioning
system may cause the refrigerant cycle to break down.

Additional refrigerant charge

♦
Additional refrigerant
Insulation of connecting portion
① Cover the connection portion of the refrigerant piping with the
pipe cover and seal them.
If neglecting to do so, moisture occurs on the piping and water will
drip out.
② Finishing and fixing
ⓐ Tie up the piping with wrapping tape, and shape it so that it conforms
to which the pipe is attached.
ⓑ Fix them with clamps as right figure.
How to relocate or dispose of the unit
•
In order to protect the environment, be sure to pump down (recovery
of refrigerant).
•
Pump down is the method of recovering refrigerant from the indoor
unit to the outdoor unit when the pipes are removed from the unit.
<How to pump down>
① Connect charge hose to check joint.
② Liquid side : Close the liquid valve with hexagon wrench key.
Gas side : Fully open the gas valve.
Carry out cooling operation. (If indoor temperature is low, operate
forced cooling operation.)
③ After low pressure gauge become 0.01MPa, close the gas valve then
stop cooling operation.
RMA012A076A_En.indb 37
Operation valve
(two-way valve)
Securely tighten the operation valve cap and the check joint blind nut after
adjustment.
Less than 15m : Not required
More than 15m : 20g/m
Compound pressure gauge
Operation valve cap
-0.1MPa
(-76cmHg)
Handle Lo
Operation valve
(three-way valve)
Operation valve
cap
Check joint
Charge hose (Designed specifically for R410A)
Operation valve size Operation valve cap
(mm) tightening torque (N·m)
φ
6.35 (1/4")
20 ~ 30
φ
9.52 (3/8")
φ
12.7 (1/2") 25 ~ 35
φ
15.88 (5/8") 30 ~ 40
To cover the connecting portion with insulation
materials, cut upper portion and then seal it
Vinyl tape
with insulation materials.
Insulation
Refrigerant piping
Electrical wiring
Covering tape
Drain hose
Tapping screw
• Forced cooling operation
Turn on a power supply again after a while after turn off a power supply.
Then press continually the ON/OFF button 5 seconds or more.
21 Series
26 Series
– 37 –

- -
'14•SRK-T-164
Pressure gauge
Gauge manifold
(Designed specifically for
R410A)
Handle Hi
Charge hose
(Designed specifically for R410A)
Vacuum pump adapter
(Anti-reverse flow type)
(Designed specifically for R410A)
Vacuum pump
Check joint blind nut
tightening torque (N·m)
10 ~ 12
Cover the exterior portion with cov-
ering tape and shape the piping so it
will match the contours of the route
that the piping to take. Also fix the
wiring and pipings to the wall with
clamps.
Unit ON/OFF button
Unit ON/OFF button
22-Jan-14 09:00:41