Periodic Checks - Arneg Mini Booster Guía De Instalación Y Manejo

Operation
The operation of the refrigeration unit is controlled by a microprocessor control unit that maintains the evaporation and
condensation pressures at the desired values depending on the operating temperatures.
The control unit features a display that allows for all the operating and safety parameters of the refrigeration unit to be
controlled. Make sure that the temperature in the compressor crankcase is above 30 °C.
The intake temperature must be higher than 10 K with respect to the evaporation temperature to prevent liquid from returning
to the compressor. The instructions for programming the control unit are in the "Control panel operation and programming"
Manual supplied with the machine.
In the event of an electronic malfunction, as an OPTIONAL, there is a back-up system that allows the refrigeration unit to
operate until technical assistance arrives.
Calibrating the main high pressure and safety pressure switch
"Safety accessories" are defined as devices designed to protect pressurised systems from values that exceed the safety
limits of the system.
The Directive 2014/68/EU (PED = European Pressure Equipment Directive) describes two safety devices:

pressure limiting device such as safety valves, rupture discs, crush bars, driven safety device (CSPRS);

limiting devices that activate the control systems, which close or close and shut down the system, such as switches
activated by pressure, temperature or fluid level, safety measuring, control and regulation safety devices.
The pressure switches used by Arneg S.p.A. are classified in category IV of the PED. The technical files indicate that the
maximum permissible pressure (PS) for the system is 120 bar.
According to EN 378-2, Tab. 2, the calibration pressure of the safety pressure switch (without discharge device) must be less
than or equal to the maximum permissible pressure (PS):
Pset = 115 bar
Therefore Pset < 115 bar is the calibration pressure for the safety pressure switch on the High pressure side of the system.
These pressure switches must be calibrated by the manufacturer.
In some cases, double pressure switches are used in which the low pressure control of the system is incorporated. Safety
concerns the high pressure side, while the low pressure side is considered to be control.
If the pressure switches are triggered due to high pressure, they must be reactivated manually by pressing the reactivation
button. If the system stops due to a power failure, the temperature of the CO
external temperatures in the place where the machine is installed) and therefore also its pressure. In the event that the
pressure of the CO exceeds the max PS of the system, the safety valves will discharge the excess CO
2
If there is a low refrigerant level error when the machine is restarted, it is necessary to top it up until the desired level has
been reached. Always have a quantity of CO
N.B. All these operations must only be performed by specialist technical personnel.

15. Periodic checks

Once a week, check the correct operation of the refrigeration unit in the following way:

Instruct the personnel involved in the periodic checks on the intervention procedure in the rooms;

Firstly check that the control panel is working efficiently and that no warning light is on;

Open the door, remaining in a protected position (lateral, behind the door), in order to avoid being hit by air or gas flows,
hot or cold;

Wait a few minutes before entering the room, in order to allow ventilation with the door open; if necessary activate
forced ventilation;

Check that there are no abnormal noises, remaining at the access threshold;

Wear the protective headphones and enter with caution;

If stains, liquid leaks or anything else indicate any malfunctions, SUSPEND THE INSPECTION AND EXIT THE
ROOM;

If there are no malfunctions, continue the inspection.

Check the CO level in the tank;
2

Check the condition of the pipes;

Check the CO compressor oil level;
2

If CO leaks during defrosting, check the solenoid valve.
2
05060197 00 09/2020
available to be able to deal with possible power failures.
2
Mini Booster
CO
in the system may increase (depending on the
2
Transcritical Rack
2
English
into the atmosphere.
2
25