TCM MMCUT18AS2, Service Manual, Page: 13 / 127

13
4.5 Adding Refrigerant after Long-Term
System Operation
Procedure
1) Connect the charge hose to the 3-way service
port and open the 2-way and 3-way valve.
Connect the charge hose to the valve at the
bottom of the cylinder. If the refrigerant is R410A,
place the cylinder bottom-up to ensure liquid
charge.
2). Purge the air from the charge hose.
Open the valve at the bottom of the cylinder and
press the check valve on the charge set to purge
the air (be careful of the liquid refrigerant).
3) Place the charging cylinder onto the electronic
scale and record the weight.
4) Turn on the air conditioner in cooling mode.
5) Open the valves (Low side)on the charge set and
charge the system with liquid refrigerant.
6).When the electronic scale displays the proper
weight (refer to the gauge and the pressure of the
low side), disconnect the charge hose from the 3-
way valve’s service port immediately and turn off
the air conditioner before disconnecting the hose.
7). Mount the valve stem caps and the service port.
Use torque wrench to tighten the service port cap
to a torque of 18N.m(13.27 ft·lbs).
Be sure to check for gas leaks.
4.6 Procedure when servicing the indoor
unit refrigeration circuit.
1. Collecting the refrigerant into the outdoor
unit
Procedure
1). Confirm that both the 2-way and 3-way valves
are set to the opened position
Remove the valve stem caps and confirm that the
valve stems are in the opened position.
Be sure to use a hexagonal wrench to operate the
valve stems.
2). Connect the charge hose with the push pin of
handle lo to the 3-way valves gas service port.
3). Air purging of the charge hose.
Open the handle Lo valve of the manifold valve
slightly to purge air from the charge hose for 5
seconds and then close it quickly.
4). Set t
e 2-way valve to the close position.
5). Operate the air conditioner at the cooling cycle
and stop it when the gauge indicates 0.1MPa.
6)
. Set the 3-way valve to the closed position
immediately
Do this quickly so that the gauge ends up indicating
0.3 to 0.5Mpa.
Disconnect the charge set, and tighten the 2-way
and 3-way valve’s stem nuts.
Use a torque wrench to tighten the 3-way valves
service port cap to a torque of 18N.m.
Be sure to check for gas leakage.
2. Air purging with vacuum pump