Maintenance; General Precautions - Mitsubishi Electric MECH-iS-G07 Instructions For Installation, Use And Maintenance Manual

9 MAINTENANCE

9.1 General precautions

Maintenance operations are fundamental to keep the refrigeration system in perfect working order, not only for purely functional reasons
but also for saving energy and ensuring safety.
Maintenance activities may only be carried out by personnel with the necessary qualifications in accordance with the local laws in force.
It is also reminded that in Europe it is mandatory to comply with EU Regulation 517/2014 (F-Gas) on the prevention of emissions of
fluorinated greenhouse gases.
Precautions that must be taken during maintenance
Maintenance activities must only be carried out by technicians authorised by Mitsubishi Electric. Before any kind of maintenance is
carried out the following measures must be observed:
• The unit must be isolated from the electricity mains using the external main switch of the unit, suitable for the insertion of up to 3
padlocks, for locking in the "open" position.
• Hang a "Maintenance - do not switch on" sign on the main switch.
• Obtain the appropriate personal protective equipment (overalls, safety gloves, safety helmet, safety glasses and safety shoes);
when working on electric and electronic components, make sure to have available dielectric gloves, shoes and visor and
dielectric tools.
• Use tools that are in good condition and be sure to be familiar with the instructions before putting them into practice.
Whenever measurements must be taken or checks performed with the machine running, it is necessary to:
• Make sure that any remote control systems are disconnected; be aware that the PLC on the machine controls these and can enable
and disable the components, posing a degree of danger (for example, by powering and running the fans and their mechanical
systems, which can drag).
• Work on the open electrical panel for as short a time as possible.
• Close the electrical panel as soon as the single measurement or check has been performed.
• In case of units installed outdoors, do not work on them in case of adverse weather conditions such as rain, snow, strong wind, fog, etc.
Furthermore, the following precautions must always be taken:
• The cooling circuit contains pressurised refrigerant gas: all maintenance must be carried out by qualified personnel with the
authorisations or certifications required by the laws in force.
• The fluids in the cooling circuit must not be dispersed in the environment.
• Never keep the cooling circuit open, as the oil absorbs humidity and deteriorates.
• During venting operations, protect against possible fluid leaks at dangerous temperatures and / or pressures.
• When replacing an electronic card, always use tools suitable for the task (e.g.: anti-static bracelet).
• If replacing a motor, compressor, evaporator, condensation batteries or any other heavy component, make sure that the lifting
mechanism is suitable for the weight to be lifted.
• Before generating a vacuum in the cooling circuit, make sure to disconnect from the power supply all the phases of the electric motor
of the compressors by removing or disconnecting the electrical protections (fuses and/or automatic switch) upstream of the cooling
circuit; after performing the refrigerant charge, put the protections back in place with the power turned off before start-up..
• Contact Mehits whenever modifications must be made to the cooling circuit, hydraulic or electrical diagram of the unit, or its control logic.
• Only use original spare parts purchased directly from Mehits or from official dealers.
• Make sure that all tools, electrical cables or loose objects have been removed and that the machine has been connected perfectly
before closing and starting the unit again.
• It is not permitted to walk on or place objects on the machines. Any maintenance on the roof must be carried out using suitable
equipment to guarantee safety, such as bridging access platforms.
• Some maintenance operations in the unit pose the risk of trapping: appropriate precautions must be taken.
Installation, use and maintenance manual - Translation of the original instructions
Make sure to have read and understood the "Safety regulations" chapter, and in particular the "Residual
risks" section of this manual.
Preliminary
WARNING
EN
83