Starting Up; Preliminary Checks; 6.2 Starting Up For The First Time - Lennox Adnova THS Series Installation, Operating And Maintenance Manual

6

Starting Up

6.1

Preliminary checks

• Check that the electrical connections have been made properly and that all the terminals are securely tightened.
This check should also be included in a periodic six-month inspection.
• Check that the voltage at the RST terminals is 230± 5% or 400 V ± 5% and make sure the yellow indicator light of
the phase sequence relay is on. The phase sequence relay is positioned on the electric control board; if the
sequence is not duly observed, it will not enable the machine to start.
• Make sure there are no refrigerant leaks that may have been caused by accidental impacts during transport
and/or installation.
• Check the power supply to the crankcase heating elements (where present).
The heating elements must be turned on at least 12 hours before the unit is started.
They are automatically activated when the main switch is put on. Their function is to raise the T of
the oil in the sump and limit the quantity of refrigerant dissolved in it.
To verify whether the heating elements are working properly, check the lower part of the compressors: it should be warm
or in any case at a temperature 10 - 15 °C higher than the ambient temperature.
Fig. 6 Charles' law diagram
Pressure
The diagram above illustrates a specific property of gases (Charles' Law), which are more soluble in liquids as the
pressure increases but less soluble as the temperature increases: if the oil in the sump is held at a constant pressure, an
increase in temperature will significantly reduce the amount of refrigerant dissolved in it, thus ensuring that the desired
lubricating function is maintained.

6.2 Starting up for the first time

Instructions for THSI units and THSC units
Refrigerant connection between two units (THSI + THSC)
• THSI and THSC units are both pre-charged with nitrogen.
• Following here-attached refrigeration diagram instructions (pay attention in particular to IN/OUT) start refrigeration
connections between THSI and THSC units.
• Make the vacuum in refrigerant line between in/out of the two units.
@DNOVA THS_R410A-IOM-1304-E
T oil
T2
T1
T0
% of R410A in oil
14