Unit Start-Up; Decommissioning; Restart After Prolonged Shutdown - emmeti EH Série Manuel D'installation Et D'utilisation

Configuration parameters
Summer working temperature set point
Winter working temperature set point
Work temperature differential
Antifreeze temperature set point
Antifreeze temperature differential
Press. exclusion time of low pressure at start-up
Press. exclusion time water differential upon start-up
Circulation pump switch off time delay
Minimum time between 2 consecutive compressor start-ups
The units are tested in the factory, where they are also calibrated and
the default parameter settings are put in. These guarantee that the
appliances run correctly in rated working conditions. The machine
configuration is carried out in the factory and should never be altered.
II.8.2

UNIT START-UP

Before starting the unit, perform the following checks.
The electrical supply must comply with the specifications on the data
plate and/or the wiring diagram and it must fall within the following
limits:
variation of the power supply frequency. ±2 Hz;
variation of the power supply voltage: ±10% of the nominal voltage;
imbalance between the supply phases: <2%.
the electrical supply system must be able to supply adequate current
and be suitably sized to handle the load;
open the electric panel and make sure the terminals of the power
supply and of the contactors are tight (they may have come loose
during transport, which could lead to malfunctions);
Standard settings
7 °C
45 °C
2 °C
2,5 °C
2 °C
120"
15"
15"
360"
33
SECTION II: INSTALLATION AND MAINTENANCE
check that flow and return pipes of the hydraulic system are
connected in accordance with the arrows next to the machine water
inlet/outlet;
make sure that the air side heat exchanger is well ventilated and
clean;
Electrical connections must be made in compliance with the local
installation standards in force in the place where the unit is installed,
and with the instructions in the wiring diagram provided with the unit.
Refer to the wiring diagram to size the supply cables.
Starting the unit
This manual provides recommendations and general information
required for starting the unit. The electronic control manual also
describes all the operations required for running the unit.
Bleed the system, before starting the compressors. The uni-
ts are equipped with manual bleed valves inside the unit.
To facilitate the bleed, the pump can be activated manually from
control panel (see the control manual from the assistance menu).
The machine can be started by pressing the ON/OFF key on the
keyboard built into the machine. Using the MODE key, select an
operating mode (chiller or heat-pump). Any problems the system
encounters will be immediately shown on the display on the control
keyboard. At start-up, the first device to start in the system is the pump,
which has priority over the rest of the system. During this phase, the
minimum water flow differential pressure switch and the low pressure
switch are ignored for a pre-set time, to prevent variations caused by air
bubbles or turbulence in the water circuit or by pressure fluctuations in
the cooling circuit.
Once these time-delays are over, final consent is given to the machine,
followed after another safety time-interval by the compressor.
The compressor follows a start-up procedure with controlled
acceleration ramps. After a few minutes you can note that the
compressor will run at a speed of rotation which is proportional to the
thermal load.
IMPORTANT!
In this phase, it must be considered normal that the
flow temperature drops by a few degrees below the
set value, however remaining higher than the anti-
freeze set in the summer cycle.
II.8.3

DECOMMISSIONING

IMPORTANT!
If the unit is not used during the winter period, the
water contained in the system may freeze.
When the machine is out of use for long periods of time, it is necessary
to disconnect it from the mains by opening the master switch. All the
water contained in the circuit must be drained in time. During
installation, consider mixing the water in the circuit with the correct
proportion of ethylene glycol to guarantee protection against freezing
(see Protecting the unit from frost).
II.8.4

RESTART AFTER PROLONGED SHUTDOWN

Before starting up again, make sure that:
there is no air in the hydraulic system (bleed it if required);
water in the heat exchanger is circulating in the required amount.
the air side heat exchanger is well ventilated and clean.