Startup Preliminary Procedures - Trane CGCN Installation Operation & Maintenance

Start-Up preliminary procedures
Initial controls
Before starting the unit, even only momentarily, all the units 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.
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 to 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.
Refrigerant seals control
Trane units are delivered with the complete charge of refrigerant and are at a sufficient pressure to check the
seal after installing. If the system is not under pressure, blow refrigerants (vapors) 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
refrigerant circuit.
WARNING! Do not use the compressor to vacuum the system.
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.
WARNING! While refrigerant is being added do not exclude any control system and let the water circulate in the
evaporator to avoid the formation of ice.