Electrical motor protection
These must be in conformity with the standards applicable and be set according to the nominal current (displayed) for the speed used.
Control by fan cycling
All possible measures should be taken to prevent the motors short-cycling.
Number of cycles allowed: 20 start-ups per hour, allowing 30 seconds between 2 start-ups.
4-
START-UP OPERATIONS
PRELIMINARY CHECKS
At reception of material, make sure that material is under pressure with the help of a manometer.
Ensure that all the threads are fully tightened on fans (jolting during transportation could cause them to loosen), and the tightening of
fans connectors.
Check also if there are any breaks in the piping (breaks could occur during transportation).
LEAKAGE TESTING
It will pressure the whole circuit with a neutral gas (nitrogen R) completed a tracer (non-liquid and non-staining) to a minimum pressure
of 10 bar.
A systematic leak detection with a suitable detector will be undertaken on gascooler.
DEHYDRATION OF CIRCUITS
This operation must be carried out with all valves open (including solenoid valves) with connection to a vacuum pump of the HP and LP
sides.
The quality of drying should not be judged by the speed at which the level of vacuum is reached but on the effective time it is
held (24 hours at 0.7 mbar is a good standard).
The total increase in pressure during that period should not be more than 2.6 mbar.
The residual moisture in the system should be less than 10ppm.
When the installation is under vacuum, an insulation check of the motor should not be carried out nor should the compressors be
started before at least 1 bar of fluid pressure is reintroduced. (To prevent motor windings damage).
FAN CHECKS
Check that the fans are rotating in the correct direction, i.e. aspiring on the coil.
Fanoperation
Gascoolers fans are fitted with EC motors also called Brushless motors. All fans starts and shutdown simultaneously.
Current
Please measure the current absorbed by each motor and compare with the nominal current (displayed), taking into account the network
current.
5-
MAINTENANCE
RECOMMENDATIONS
A periodic visual check of the following is recommended:
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Cleanliness of the coil
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Position of axial fans in their collar
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State of each axial fan (tightness to shaft, mechanical state of blades etc)
If the unit is stopped for long periods of time, the fan motors should be run for at least two hours each week.
