Midea MDFA-76CRN2, Manual

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-UTSM-12
86
Manifold valve
-76cmHg
Filler hose
Filler hose
V
a
c
u
u
m
p
u
m
p
Hi -handle
Lo pressure valve
Multimeter manometer
Lo-handle
Fig-32

Loosen and remove the maintenance orifice nut of valve A, and connect the filler hose of the manifold valve
to the maintenance orifice of valve A (tighten both valve A and valve B).

Connect the filler 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 multi-meter indicate 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. Check whether the multi-meter points at
-1.0X10 Pa (-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.
5.3.1.5. Procedure of using stop valve

Open the spool until it touches the stop block. Do not attempt to open further.

Use a spanner or a similar tool to tighten the bonnet. The bonnet tightening torque is shown in Table 3
“
Tightening torque
”
.

Upon completion of installation, open all valves before trial run. Each unit has two valves of different sizes
located at the outdoor unit side. Of the two valves, one is gas valve and the other is liquid valve. The
procedure of opening/closing the valve is shown in the right figure (Fig-33).

Procedure of opening the valve: Open the square-head cover, use a spanner to capture the square head
and open it thoroughly. Then tighten the square-head cover.

Procedure of closing the valve: Same as the procedure of opening the valve, but rotate the spanner
clockwise thoroughly.