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4.- MAINTENANCE
4.1.- PREVENTIVE MAINTENANCE
- GENERAL STATE OF THE CASING:
Furniture, paint, damage due to shocks, rust spots, levelling and supporting, condition of the shock absorbers, if installed, screwed panels, etc.
- ELECTRICAL CONNECTIONS:
State of hoses, tightness of screws, earthing, current consumption of the compressor and fans and check that the unit is receiving the correct voltage.
- COOLING CIRCUIT:
Check that the pressures are correct and that there are no leaks. Check that there is no damage to the pipe insulation, that the condition of the coils
is good and that they are not blocked by bits of paper or plastic drawn in by the air flow, etc.
- COMPRESSOR:
If a sight glass is fitted, check the oil level.
Check the condition of the silentbloc mountings.
- FANS:
Check that fans turn freely and in the correct direction without excessive noise.
- CONTROL:
Check Set Points and normal operation.
4.2.- CORRECTIVE MAINTENANCE
MAKE SURE THAT THE UNIT IS FULLY DISCONNECTED FROM THE POWER SUPPLY WHEN CARRYING OUT
If any component in the cooling circuit is to be replaced, follow these recommendations:
- Always use original replacement parts.
- If the component can be isolated, it is not necessary to remove the entire refrigerant charge, if the component cannot be isolating and the refri-
gerant charge is removed, it should be removed through the Schrader valves located in the outdoor section. Create a slight vacuum as a safety
measure.
- Regulation prohibits the release of refrigerant into the atmosphere.
- If cuts must be made in the pipe work, use pipe cutters. Do not use saws or any other tools that produce filings.
- All brazing must be carried out in a nitrogen atmosphere to prevent corrosion forming.
- Use silver alloy brazing rod.
- Take special care that the flame from the torch is directed away from the component to be welded and cover with a wet rag to prevent overheating.
- Take very special care if 4-way or check valves are to be replaced since these have internal components that are very heat-sensitive such as plastic, teflon, etc.
- If a compressor is to be replaced, disconnect it electrically and un-braze the suction and discharge lines. Remove the securing screws and
replace the old compressor with the new one. Check that the new compressor has the correct oil charge, screw it to the base and connect the lines
and electrical connections.
- Evacuate above and below through the Schrader valves of the outdoor unit until -750 mm Hg is reached.
Once this level of vacuum has been reached, keep the pump running for at least one hour.
DO NOT USE THE COMPRESSOR AS A VACUUM PUMP.
- Charge the unit with refrigerant according to the data on the Rating Plate for the unit and check that there are no leaks.
PRECAUTIONS TO BE TAKEN WHEN USING OF R-410A Refrigerant:
R-410A refrigerant is used in the unit; the following standard precautions for this gas should therefore be taken:
- The Vacuum Pump must have a Check Valve or Solenoid Valve fitted.
- Pressure Gauges and Hoses for exclusive use with R-410A Refrigerant should be used.
- Charging should be carried out in the Liquid Phase.
- Always use scales to weigh-in charge
- Use the Leak Detector exclusive for R-410A Refrigerant.
- Do not use mineral oil, only synthetic oil to ream, expand or make connections.
- Keep pipes wrapped before using them and be very thorough about any possible dirt (dust, filings, burrs, etc.).
- When there is a leak, collect what remains of the charge, create a vacuum in the unit and completely recharge with new R-410A Refrigerant.
- Brazing should always be carried out in a nitrogen atmosphere.
- Reamers should always be well sharpened.
PREVENTIVE MAINTENANCE PREVENTS COSTLY REPAIRS.
THIS REQUIRES PERIODIC INSPECTIONS:
IMPORTANT
ANY TYPE OF WORK ON THE MACHINE.
Wet rag
Nitrogen
28
Direction of the flame
Silver alloy welding rod
Component to be welded
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