Commissioning; Start-Up Sequence; Check Immediately - CIAT condenciat CD Instruction Manual

15 - COMMISSIONING

● Fill the system with refrigerant:
● Close the liquid outlet valve
● Connect the refrigerant bottle to the charging valve. Do not tighten it.
● Open the valve on the bottle momentarily to drain the coupling. Retighten the coupling
● Open the charging valve
● Open the tap on the refrigerant bottle
● Keep the low pressure switch closed
● Set the compressor control switch (marked on the wiring diagram) to ON. The compressors must start up after the short-
cycle protection time delay.
● Activate the compressors in series.
● Top up the charge from time to time, close the tap on the refrigerant bottle and open the liquid outlet tap.
● Check the fluid flow in the sight glass and top up the charge gradually.
● Make sure the charge is correct by monitoring the overheating and the subcooling, remove the charge devices, making sure
that tap on the refrigerant bottle is properly closed and that the liquid outlet valve is fully open (seat at the rear).

15.1 Start-up sequence

● Run the cold or heat emitters to provide a thermal load so that the cooler can operate.
● Close the switch (marked on the wiring diagram).
● Once the cabinet has been electrically connected and the main switch closed, the crankcase heater is under voltage. The
compressor must be started up a few hours (6 hours) after the heater has been powered up.
● The unit's internal safety devices are activated. If a safety device is deactivated, find the fault and reset the safety device (in
the case of a safety device with manual reset).
● The control stages should operate in series, depending on the request.
NOTE 1: Use either of the following to turn off the unit in non-emergency situations:
- The switch marked on the wiring diagram.
- A potential-free (dry) contact on the automatic operation control.
Do not use the master switch as the electrical panel must remain under voltage (crankcase heaters).
NOTE 2: During the months when the system is in use, the electrical panel must be permanently under voltage so that the
crankcase heater(s) are under voltage when the compressor(s) are stopped.

15.2 Check immediately

● That the condenser fan(s) are turning in the right direction (if not, swap two general supply wires)
● That the discharge is heating (using a contact sensor)
● That the input current is normal (see table and value affixed to the compressors)
● Check the operation of all the safety devices (see table for setting value)
NOTE: When a condensation unit starts to operate, a number of problems may be caused by insufficient suction pressure or
excessive condensation pressure:
The main scenarios are as follows:
Suction pressure too low
- Insufficient air flow on the direct expansion coil (the fans are turning in the wrong direction, operating pressure too low,
filter fouled)
- Temperature of conditioned air too low (insufficient thermal load)
Excessive condensation pressure
- Poor condenser ventilation (suction or discharge blocked, fans turning in wrong direction)
- Suction air too hot (recirculation)
IMPORTANT
As SCROLL compressors rotate in a specific direction, immediately check the following:
1/ The discharge temperature rises quickly
2/ The pressure in the high pressure switch rises and the pressure in the low pressure switch drops
In the event of a problem, check the unit's power supply and reverse the order of the phases on the main power cable.
NA06.130 C EN - 8