@DNOVA THS_R410A-IOM-1304-E
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6.5
Checks during operation
Check the phase sequence relay on the control board to verify whether the phases occur in the correct sequence: if
they do not, disconnect the unit from power supply and invert two phases of the incoming three-pole cable.
Never
attempt to modify internal electrical connections: any undue modifications will immediately invalidate the
warranty.
6.6
Checking the refrigerant level
After a few hours of operation, check whether the liquid level indicator has a green ring: a yellow colour indicates the
presence of humidity in the circuit. In such a case the circuit must be dehumidified by qualified personnel.
Large quantities of bubbles should not appear through the liquid level indicator. A constant passage of numerous
bubbles may indicate that the refrigerant level is low and needs to be topped up.
Make sure the overheating of the cooling fluid is limited to between 5 and 8 °C: to this end:
1 ) read the temperature indicated by a contact thermometer placed on the compressor intake pipe;
2 ) read the temperature indicated on the scale of a pressure gauge likewise connected to the intake side; refer to
the pressure gauge scale for the refrigerant R410A.
The degree of overheating is given by the difference between the temperatures thus determined.
Make sure that the Sub-cooling of the cooling fluid is limited to between 3 and 5°C, to this end:
1 ) read the temperature indicated by a contact thermometer placed on the condenser outlet pipe;
2 ) read the temperature indicated on the scale of a pressure gauge connected to the liquid inlet at the condenser
outlet; refer to the pressure gauge scale for the refrigerant R410A.
The degree of Sub-cooling is given by the difference between the temperatures thus determined.
Warning:
All THS units are pre-charged with nitrogen. Any top-ups must be made using the
same type of refrigerant. This operation is to be considered extraordinary
maintenance work and must be performed by qualified personnel only.
Warning:
The refrigerant R410A requires “POE“ polyolester oil of the type and viscosity
indicated on the compressor rating plate.
For no reason should oil of a different type be introduced into the oil circuit.
