Start-Up Operations - Profroid GSB Notice D'instructions

ELECTRICAL CONNECTIONS
General information
The machine is designed in accordance with EN60204-1.
All cabling on site must conform to the legal standards in force in the relevant countries and to EN60204-1.
Except for special operation, the nominal current must be:
power circuit: 400V/3/50Hz + Earth
control circuit: 230V/1/50Hz (pressure switches – crankcase heaters).
Cabling is determined according to:
- Maximum nominal intensity
- The distance between the unit and its power source.
- The protection at the source
Electrical motor wiring
Certain models are designed for a Part Winding Start or PWS. The commutation delay between these 2 start-ups must be 1s ± 0.1s.
When connecting the motors, the order of the phases must be observed on the two windings (L1 L1 - L2 L2 - L3 L3).
However, the motors can also be started Direct-on-Line, as can the other models in this range.
The compressor motors are fitted with an anti-short cycle mechanism allowing a maximum of 6 start-ups per hour..
Important
: the maximum imbalance between phases is 2% in voltage and 10% in current per motor.
ADDITIONAL SAFETY CONTROLS
Safety Features
Some safety features stop the compressor instantly.
Crankcase Heaters
Crankcase heaters must operate when compressor is stopped
AUTOMATIC MECHANICAL DEVICES
As we do not design the installation, we are responsible only for the electrical layout and refrigeration equipment.
Nevertheless, we recommend:
- providing a pump down or pump out control to close the system down
- providing for an automatic closure of one or more refrigerant fluid solenoid
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START-UP OPERATIONS

PRELIMINARY CHECKS AND OPERATIONS
General information
Ensure that all the threads are fully tightened on connection flanges, flexible connections and cable (jolting during transport could
cause screws and bolts to loosen).
Check also, for same reasons, if there are any breaks in the piping.
Ensure that the flexible connections are not in contact with metal parts. Vibrations from the compressor can cause wear in these
until they rupture at the point of friction.
Switch on crankcase heaters 24 hours before start-up.
Before starting up a machine with pressurised tanks, all service valves must first be opened upstream and downstream and all
external valves closed..
Leakage testing
Pressurise the whole system using a neutral gas (Nitrogen R) with a (non-liquid, non-colouring) tracer, at a minimum pressure of 10
bars and at a maximum pressure of less than 20.5 bars, isolating the LP (low pressure) switches.
Important
: If the LP circuit is fitted with a safety valve (e.g.: on the suction accumulator) the test pressure on that part of the
circuit should be approx. 20% below the operating pressure of this valve.
Thorough leakage detection using a suitable detector should be carried out on the unit.
After these tests, the gas must be removed. Fit the drier cartridges in their casing.
Dehydration of circuits
This operation must be carried out with all valves open (including solenoid valves) with connection to a vacuum pump:
of the low pressure side
-
of the high pressure side
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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 20ppm.
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.
valves during a safety cut-out on the compressor.
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