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10. OPERATOR RESPONSABILITIES
It is important that the operator is properly trained and familiar with the equipment before working on the unit. In
addition to reading this manual, the operator must study the manual operation of the microprocessor and the
wiring diagram to understand the sequence of start- up, operation, shutdown sequences, and the criterion of
operation of all safety devices. During the initial start-up of the unit an authorized technician is available to answer
any questions and educate on the proper functioning. We recommend the operator to maintain a record of the
operating data for each unit installed and all maintenance activities and periodic service. If the operator observes
abnormal or unusual operating conditions, consult the authorized service technician.
11. START-UP PRELIMINARY PROCEDURES
o
STARTING CHECK
Before starting the unit, even only momentarily, all the machinery supplied by the chilled water, like the air
handling units, pumps, etc. have to be checked. The pump auxiliary contacts and the flow switch have to be
connected to the control panel as indicated in the electrical diagram. Before carrying out interventions on the
valve regulations, loosen the relevant valve gland. Open the discharge valve of the compressor. Open the liquid
shutoff valve placed on the liquid line. Measure the suction pressure. If it is lower than 0.42 MPa jumper and strain
the solenoid valve on the liquid line. Bring the suction pressure to 0.45 MPa, then remove the jumper. Charge all
the water circuit progressively. Starts up the water pump of the evaporator with the calibration valve shut and then
slowly open it.
Discharge the air from the high points of the water circuit and check the direction of the water flow. Carry out
calibration of the flow by using a measurer (if present or available) or by means of a combination of the readings
of the manometers and the thermometers. In the starting phase calibrate the valve on the pressure difference
read on the manometers, carry out drainage of the tubes and then carry out fine calibration on the temperature
difference between the water in and the water out. The regulation is calibrated in the factory for water in the
evaporator at 12°C and water out at 7°C. With the general switch open, check that the electrical connections are
tightly clamped. Check for any possible refrigerant leaks. Check that the electrical data on the label correspond to
those of the mains supply. Check that the thermal charge available is appropriate for starting.
o
REFRIGERANT SEALS CONTROL
Trane units are sent with the complete charge of refrigerant and are at a sufficient pressure to check the seal after
installing. If the system were not under pressure, blow refrigerants (vapour) into it until pressure is reached and
look for leakage.
After having eliminated the leakage, the system has to be dehydrated with a vacuum pump up to at least 1mm Hg
- absolute pressure (1 Torr o 133.3 Pa). This is the minimum recommended value to dehydrate the plant.
CAUTION Do not use the compressor to vacuum the system.
o
REFRIGERANT CHARGE CHECK
Trane units are supplied with a complete charge of refrigerant. If bubbles can be seen through the peephole with
the compressor running with a full charge and steadily, it means that the refrigerant charge is insufficient.
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