Mitsubishi Electric ECOV-X37VA Manuel D'installation page 12

Installation process and safety precautions for use with R744
<Steps for installation>
Determination of installation area
Check of condensing unit
specifications
Drawing of working diagrams
Installation of showcase/unit cooler
Refrigerant piping work
(Dry, clean, tight)
Drain piping work
Electrical wiring
Foundation work of condensing unit
Installation of condensing unit
Refrigerant piping work
Air tightness test
Heat-insulating work
Vacuum drying
Refrigerant charging
Electric wiring of condensing unit
Target evaporation temperature setting
Test run
Leakage check
Providing guidance on the usage
to the end users
WT09614X03_GB
<Safety precautions for use with R744>
• Check that the unit is intended for use with R744.
• Check the design pressure.
(High pressure 12.0 MPa, Low pressure 8.0 MPa)
• Use new pipes only.
• Check that the unit is intended for use with R744.
*1
• Check that the inside of the pipes is in proper condition.
• Braze the pipes under nitrogen purge.
• Use a torque wrench to tighten nuts.
• Carry an R744 leak detector.
Refer to *1.
• Do not allow the refrigerant oil to be exposed to air for more than 10 min-
utes, even during servicing.
• Install a safety valve on the high-pressure side.
• Perform an air tightness test.
(Design pressure for refrigerant pipes and indoor units 8.0 MPa) x 24 hours
The condensing unit has been subjected to an air tightness test prior to shipping.
• Perform vacuum drying for one hour after the vacuum level reaches 266 Pa
on the vacuum gauge.
• Use a specified vacuum pump with a check valve.
• Use the proper amount of refrigerant and the proper amount of additionally
charged refrigerant.
• Charge the system with liquid refrigerant only.
• Use a specified gauge manifold and a specified charging hose.
• Write down the amount of charged refrigerant on the nameplate on the front
of the unit.
• Check that the unit is not under short-cycling operation.
• Check that the target evaporating temperature is appropriate.
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