Trane TTKE12SB5EAA, Owner'S Manual & Installation Manual

Page: 67 / 100

18 MCXE-IOM
Air Evacuation and Refrigerant Charge
R32
Caution
Check to make sure there is no refrigerant leak after
completing the installation work. If there is refrigerant leak,
ventilate the area immediately and evacuate the system.
Fan coil installation should be 1.8 meters hight from the
floor. 1.
2.
Air and humidity and the enemy of the air-conditioning system
because humidity well react with R32 refrigerant and turns into
acid, which will corrode the wire coil and reduce the compressor
oil’s efficiency. Evacuation is a must to prevent refrigerant
system from air and humidity.
Do not use refrigerant in system to evacuation instead of
vacuum. Because it will take compressor oil (R32 is ester
type oil) have a chance to contamination with moisture cause
to damage to compressor. Make a vacuum unit until pressure
drop to 29.72 Hg.vac (5,000micron/660pa) or less than
76 cmHg and continue vacuum for 30 minutes.
Suction Line
Liquid Line
Service Hose
Electronic
Connection
Vacuum Pump
Fill up the refrigerant via valve at suction line until pressure
is around 120-150 psig (Don’t forget to evacuate air first).
Turn on evaporator and condensing unit.
Fill up the refrigerant into suction line at the proper quantity
while the unit is working.
Let machine run for at least 20 minutes. Read pressure from
pressure gauge “at low side”, and read current from amp-
meter. Usually, suction line pressure should be around
120-150 psig. •
•
•
•
If suction pressure is lower than normal and electric current
is far below full load ampere, it indicates that refrigerant is
inadequate. It need to add more refrigerant.
If suction pressure is higher than normal and electric current
is over the full load ampere, and you notice some water
spray holds on the compressor, it indicates over cooling
system. It need to release some refrigerant.
•
•
Evacuation
Normally, this needs to be done immediately after air evacuation
per the following steps.
How to fill up refrigerant
If the pressure readings of suction line are in the range stated
above and electric current reading is at full load ampere of
condensing unit, it indicates that refrigerant’s volume is sufficient.
Current checking
Caution
Connect the middle hose of service gauge to the vacuum pump,
then connect the hose at the low side to “service valve” of air-
conditioning at suction line. Connect the hose at the high side
to “service valve” at liquid line.
Evacuation Procedure
To fill up R32 refrigerant is the final step of installation. After
leakage check and power wiring, fill up R32 refrigerant to the
system.
Fill up refrigerant into the system
Suction
Pressure
R32 can charge both liquid and gas state.