IOM / @DNOVA_THS-0508
13
5.
STARTING UP
a. 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 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.
The diagram above illustrates a specific proper
ty 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.
b. Starting up for the first time
Start-up instructions for THI 025-073 AND THC 025-073 units
Refrigerant connection between the two units.
THI 025-0473 and THC 025-073 units are both pre-charged with R407C refrigerant.
Following here-attached refrigeration diagram instructions (pay attention in particular to IN/OUT)
start refrigeration connections between THI and THC units.
Make the vacuum in refrigerant line between in/out of the two units.
Electrical connection
Open the frontal panel of the two units.
Turn THI unit QS main switch OFF.
Switch OFF THC unit Q01 automatic switch.
Insert 230/1/50 (main power) power supply cable using one of the special holes you can find on
THI unit sides and connect it to QS main switch.
Pressure
% R407C in oil
Oil T