Daikin JEHBSCU0200M1 Technical Manual page 27

9.13 Running the unit
• Run the unit and check compressor and condenser fan operation.
• Check system pressures and temperatures, gas charge and running currents of motors to
ensure correct operation.
• Check compressor superheat.
• Final adjustment of safety switches setting and fan speed controller.
• Check compressor oil level and adjust as necessary.
• Carry out final leak test and ensure all panels/covers are fitted and screws tightened.
• Log all information along with the system model and serial numbers for future
reference.
• Ensure that the customer / responsible person are provided with basic operating
instructions and where electrical isolators are situated in case of emergency.
Important Information!
Compressor operation
Scroll compressors are designed to run only in one direction. This is not an issue with single
phase compressors as they will always run in the correct direction. Three phase scroll
compressors however can run in either direction depending on the connection of the three
phases to the unit. Correct rotation can be determined by a drop in suction pressure and a rise
in discharge pressure when the compressor is energized. Running the compressor for a short
period of time in reverse direction will have no negative impact but prolonged running in
reverse direction may cause premature failure. To reverse the rotation on a three phase scroll
compressor, simply swap connection of any two of the three compressor phases and recheck
operating pressures.
Vacuum operation:
Do not operate scroll compressors in a vacuum condition, as this will cause the scrolls to
overheat very quickly causing premature failure.
System charge:
Ensure an adequate liquid charge has been introduced to the high side of the system before
starting to ensure a minimum operating pressure on the suction side of 0.5 bar is maintained,
otherwise overheating of the scrolls and subsequent damage may occur.
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