Mitsubishi Electric ECOV-X37VA Manuel D'installation page 35

8-2-4. Procedures for stopping the vacuum pump
To prevent the backflow of vacuum pump oil to the unit, open the relief valve on the vacuum pump, or draw in air by loosening
the charging hose. Then stop operating the vacuum pump.
Use the same procedures when stopping a vacuum pump with a check valve.
8-2-5. Required precision of vacuum gauge
1)Use a vacuum gauge that can measure the vacuum pressure of 266 Pa and measure at 1 Torr (130 Pa) incre-
ments.
2)A general gauge manifold cannot measure the vacuum pressure of 266 Pa.
8-2-6. Operating the valve check joint
1)Procedure to operate the refrigerant service valve (three-way valve) <liquid> and the refrigerant service valve
(three-way valve) <injection>
• Remove the cap, and turn the valve rod with pliers. Turn
the valve rod counterclockwise to open the valve, and
clockwise to close it.
• Tighten the cap to a torque of 25 to 35 Nꞏm at the comple-
tion of valve operation.
Failure to replace the cap will lead to refrigerant leakage.
Do not damage the refrigerant sealing inside the cap.
• Fully open
Both the upstream and downstream pass refrigerant. Ser-
vice port does not.
• Half open
The upstream, downstream, and service port all pass re-
frigerant.
• Fully closed
The downstream and service port pass refrigerant. Up-
stream does not.
Refrigerant flow direction
Service port
Service port
Service port
Service port
35
Cap
Upstream
Downstream
Upstream
Downstream
Upstream
Downstream
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