Refrigerant Replenishment Quantity - Midea MTA1-76HR Technical Manual

Midea R22 T1 side-discharge duct manual

Use a vacuum pump to expel the air.

Loosen and remove the maintenance orifice nut of valve A, and connect the filter hose of
the manifold valve to the maintenance orifice of valve A. (Tighten both valve A
B.)

Connect the filter hose adapter to the vacuum pump.

Open the low pressure (Lo) handle of the manifold valve completely.

Start the vacuum pump to extract air. At the beginning of extracting air, slightly loosen the
maintenance orifice nut of valve B.

Check whether any air enters it (the vacuum pump noise changes, and the multimeter
indicaters from negative to 0). Then tighten this maintenance orifice nut.

Upon completion of vacuuming, tighten the low pressure (Lo) handle of the manifold valve
completely and stop the vacuum pump.

Keep extracting air for over 15 minutes, and check whether the multimeter points at
-1.0×10Pa(-76cmHg).

Loosen and remove the square-head cover of valves A and B. After opening valves A and B
completely, tighten the square-head cover of valves A and B.

Remove the filler hose off the maintenance orifice of valve A, and then tighten the nut.

3.6 Refrigerant replenishment quantity


If the connecting pipe length of indoor unit and outdoor unit is more than 10 meters, then it needs to
replenish refrigerant into the system for the unit normal operation.

The refrigerant for replenishment is R22.

The calculation for the replenished quantity of refrigerant is as the following formula:
Q =Qs× Lt
Q: The replenishing amount of refrigerant; Unit: kg.
Qs: Corresponding unit length of replenishing amount with different liquid pipe diameters; Unit: kg/m.
Diameter of liquid-side pipe
Lt: Total length of extend liquid pipe, it is also means to the total length of liquid pipe; unit: m.
24
Ф9.52mm
Quantity of refrigerant replenished
0.065kg/m
MCAC-RTSM-201301-01
and valve