Safety Devices (Fig. 5) - Arneg HP3 Guia De Instalacion

Filling with coolant
Before beginning the filling process, it is important to be sure that:
- the system is perfectly sealed and that the pressure test and vacuum test have been carried out
- the safety devices are all operational and appropriately calibrated
- the oil level is as required
- the condenser is operating regularly
This operation must be carried out after the system has been tested to have a perfect seal.
- Connect the tank (creating a vacuum in the connection tubing as well) to the high pressure circuit,
using the connector found between the condenser and the liquid reserve.
- Fill using the connector with the contents of the tank in a liquid state.
- Fill, replacing the tank when empty, until the pressure between the tank and the system is equalized.
When the pressures are equalized, it will no longer be possible to fill from this connector.
- With tanks with two connectors, do not turn the tank upside down.
- Connect the liquid stage of the tank to a connector from the intake line to finish filling.
- As it is impossible to create a vacuum in the tank section of tubing, connect the tubing making sure
that there is coolant inside the tube.
- Turn on a compressor so as to reduce the pressure in the intake line, open the tank tap, and complete
the filling process.
Warning!This step is the most dangerous, as excess coolant capacity could cause
backflow of excessive liquid to the compressor, damaging it.
Pay attention to the temperature of the compressor discharge (above 50°C) and the
temperature of the oil tank (10°K above evaporation temperature).
To reduce the risk, it is possible to fill the system using a connector located on the
liquid reserve, closing the tap on the reserve outlet.
In this way, with the compressor on, the section of tubing below the reserve will
reduce its pressure, allowing the liquid contained in the tank to move towards the
system. This operation may trip the high pressure switch -- pay attention to the
condensation pressure value.
- Continue the filling process until the liquid level indicator on the reserve outlet indicates that it is
completely full.
- Before starting the system, consult the manual for installation and use of the electronic control device.
Operation
Unit operation is controlled by a microprocessor control unit that maintains evaporation and
condensation pressures within the desired values, based on the operation temperatures.
The control unit is provided with a display that makes it possible to control all the operational and safety
parameters for the unit. Instructions for programming the electronic unit can be found in the manual for
installation and use of the electronic control device.

15.Safety devices (Fig. 5)

Devices intended to protect systems under pressure from values that exceed the system's safety limits
are known as "safety accessories."
Directive 9723/EC (PED = European directive for pressurized devices) describes two safety devices:
- device for limiting pressure, such as a safety valve, bursting disc safety devices, buckling rods,
controlled safety pressure release systems (CSPRS);
- limiting devices, which either activate the adjustment system, which closes or closes and shuts down
the system, such as switches activated by pressure, temperature, or fluid level, or safety related
measurement control and regulation devices (SRMCR).
The CSPRS safety valve is installed on the liquid container and is calibrated at 28 bar. The said valve
should be replaced every 5 years.
The pressure switches used by Arneg S.p.A. (SRMRC) are classified in Category IV of the PED
directive. A cartridge type safety pressure switch with fixed calibration and automatic reset is installed
on the high pressure side. A cartridge pressure switch with fixed calibration at 28 bar and manual
reset, which cannot be intercepted by the tap fitted on the compressor discharge, is installed on each
compressor.
The electrical panel contains the low pressure transducer, two variable calibration high pressure
switches to control the fans, and a variable calibration low pressure switch.
05060114 00 09/07/2010
HP3
English
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