Lennox INNOV DM R Series Application Manual page 51

7.3 Checks during operations
Check the phase sequence relay (only DX versions) 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.
7.4 Checking the refrigerant charge (DX versions)
·
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 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.
·
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.
Warning: TREF units are design for R410A refrigerant.
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.
Warning: The air cooled (split) unit are Factory pre-charge with Nitrogen
INNOV@ ECFAN DHR -AGU-0912-E • 19 •