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INSTALLATION INSTRUCTIONS
5.9. Circuit sealing
Before Charging with refrigerant, systematically search for leaks on all fittings, and seal them if necessary.
5.10. Evacuation
Evacuate the installation to reach a residual pressure of about 200 micrometres of mercury (0.27 mbar), guaranteeing a good quality of vacuum.
It is advisable to drain the HP and BP circuits simultaneously in order to reduce the operation time and ensure an identical level of vacuum
throughout the circuit.
6. REFRIGERANT CHARGE, POWERING UP AND MAINTENANCE
If the following manipulations are performed in potentially explosive atmospheres, Tecumseh recommends referring to Standard EN 378. Part 4
prescribes the general safety guidelines and provides guidelines for interventions in equipment using flammable refrigerants..
6.1. General recommendations
The electrical boxes will be properly installed and closed before charging the refrigerant and switching on installation.
HFO levels in the air will be monitored throughout the whole refrigerant charge and maintenance period.
The work area will be ventilated throughout the procedure.
6.2. Refrigerant charge
The provisions in Parts 2, 3 and 4 of EN 378 must apply to prevent the risk of refrigerant emission during refrigeration system filling and emptying
operations.
Limit the refrigerant load so that the pressures are in the operating window defined by Tecumseh.
Never start the compressor if the vacuum is not broken in HP and BP.
The components will be grounded before starting the refrigerant charge.
Load the installation only with the refrigerant or one of the refrigerants for which the compressor was designed (see nameplate).
The refrigerant charge will always be in liquid form, to keep the mixture in the right place.
Do not add any additives or dyes.
6.3. Risk of refrigerant Over Charge
If the main parts of the compressor are submerged due to excess refrigerant charge, this can cause the compressor housing to burst. Immersion
of the crank case, connecting rod, piston and cylinder in the liquid creates a hydraulic blockage preventing the compressor from starting: this is
therefore a blocked rotor situation. If, for some reason, the compressor protector does not intervene quickly enough, a high current in the motor
winding will create a rapid rise in temperature. This will cause the liquid to vaporise and the pressure in the compressor housing to increase rapidly.
6.4. Checks when commissioning
• Calibrate electrical protective devices, adjust the set/cut points of the regulatory and safety devices.
• Fully open the service valves.
• Check the operation of the oil heater, if present.
Tecumseh compressors are protected by an external or internal over load protector , the principle of which is based on a temperature/current
combination. Like any protective device, it is normal for the compressor to trip on overload protector when it is operating outside the Tecumseh's
recommended application window.
When operating conditions are stabilised, do the following checks:
• Tension(Voltage) and intensity ( Current) absorbed by the compressor;
• HP and BP pressures from the installation;
• Overheating, undercooling, return gas temperature, discharge temperature;
• Search for leaks;
• Carry out a general inspection of the installation (cleanliness of installation, abnormal noise, etc.). Visually inspect the refrigeration system
For installations operating with a flammable refrigerant, check if the leak detection equipment is working properly.
Do not add oil unless the pipes exceed 20 m; in this case, use the oil recommended by Tecumseh.
6.5. Maintenance
Tecumseh recommends securing the maintenance area in accordance with EN 378 Part 4
Below is a non-exhaustive list of recommendations:
• Obtain a permit for high-temperature work (if necessary);
• Ensure that no flammable material is stored in the work area and that there are no sparks in the work area;
• Switch off electrical appliances;
• Keep heat sources away to avoid explosions;
• If a heat source is present in the workplace, make sure a fire extinguisher is available;
• Ensure that the work area is properly ventilated, before intervening on the refrigeration system or before welding or tender brazing work;
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