MV / LV cabins maintenance The operation and maintenance of the cabins are meant to ensure high reliability (i.e. the early detection of anomalies, the failure prevention and monitoring functional) and to ensure safety. Personnel training is given responsibility for the proper application periodic checks. The following description defines the basic operations for the maintenance of MV / LV bearing in mind that the booths presenting a great diversity in their composition the procedure goes applied from time to time according to the equipment present. Obviously, if there are any equipment not mentioned in the cards following, the same will be built or upgraded. The scheduled maintenance must be carried out always circuit is not energized by performing the procedures for commissioning safety of the system and the display of related warning signs. Regular checks are: Cabin N Daily Weekly Monthly Every 3 1 Remove any materials not related plants and perform the cleaning of the premises. 2 Integrity Control ventilation grille cleaning of the same. 3 Check for devices protection equipment and fire suppression. 4 Upload etinguishers 5 Check for warning signs and documentation system 6 Run the control of the state of preservation of the protection structures against direct contact nets, gates, pleiglas, etc. 7 Painting outside cabin and reconstruction waterproof cover MV Isolators Perform cleaning and visual inspection integrity of the insulators. Verify the effectiveness of interlocks mechanical and / or electrical disconnect between line and earthing. Run the tightening control of electrical connections to the insulators. Verify the efficiency of locking devices that prevent access to live parts. Check the efficiency of mechanical signaling position Check the efficiency of the ground
connections of the ground Check the continuity of conductors made grounded metal structures and installed equipment. Fuses 1 Visual check to be carried 2 Check of the project electrical characteristics SF6 Switches Visual inspection equipment integrity and cleaning Check the pressure on the pressure switch (if present) for any gas leaks. Perform five mechanical closing and opening Visual inspection of the poly (resin parts). Visual inspection of the command and transmission Check the tightness of the ground Check the tightness, contacts isolated (only for withdrawable circuit-breaker). Verify the supply voltage of the electrical accessories of the command. Measure the insulation resistance every 5 years For auiliary circuits control the operation of the reports and motor control (if equipped). Checking the functionality of the interlocks Check the springs and replace if damaged Grease with suitable points loading of the springs of the command, the points of loading of the opening spring and latches and opening. Protection power relay Visual inspection equipment integrity and cleaning Visually check the calibration values of electrical parameters with those design. Simulate the operation of the protection act mechanically on the release device switch
For overcurrent protection (50-51), of ground (50N-51N) and minimum voltage, type indirect: Visually check the calibration values of electrical parameters with those design. Check the correct operation of the protections overcurrent and ground with the appropriate instrument. Before commissioning, check that the voltage current circuits are not left open. Resin transformer room temperature sensors feature PT 100 / PTC Control unit Cleaning from dust, dirt deposits, any foreign bodies on the windings Hardware link to star / delta and terminals MV / LV Control winding insulation between them and to earth Centering control wraps. MV / LV core- Magnetic meter Control plates registry blocks suspension with a torque wrench Oil transformer room Perform eternal visual inspection for eternal verify the integrity of the equipment. Where available to perform a visual inspection of the supply pipes. Check the condition of the painting conservator, radiators and boes cable entry, and if there are signs evidence of corrosion, program a etraordinary intervention for painting partial or total. Perform cleaning of insulators passers, check the integrity, the absence of
breakage, cracks and signs of shock surface that may cause undesired efficiency. Check the tightness of power cables on for loops with torque wrench as to the manufacturer's instructions and check the tightening the bolts, cleaning connections and the continuity of the conductor grounding and replace any terminals conductors and deteriorate. Remove any oidation from the terminals power and protect the same product with specific. Perform a sample of oil tested strength. Check that the oil level is below the minimum, if any replenishments have to be made with dielectric oil of the same type and try it and see that there is no loss of oil. Check the Bucholz relay make cleaning and visual inspection to check the status of conservation apparatus. After re-fed auiliary circuits cause the intervention of alarm and lock instrument, acting on the button proof. Verify that the intervention of the various levels cause the intervention of alarm and / or opening switches upstream and downstream in the transformer as provided by the manufacturer. For the thermostat to perform the cleaning and the visual inspection to check the status of conservation apparatus. After re-fed circuits MV METERS in the room Visually inspect the eternal verify the integrity of the cabinets. Where accessible perform visual inspection of the supply lines. Perform internal and eternal cleaning of paintings by compressed air and vacuum Check the condition of structures protection against direct contact (screens metal, etc..). Check the tightness of bolts, cleaning
the connections and the continuity of the conductor grounded and replace the any damaged terminals and conductors. Verify the efficiency of the devices block that prevent access to parts voltage. Check the efficiency of lighting internal framework if present. Check the efficiency of the resistors condensation and thermostats (if any). Check tightness of connections power Program maintenance 6/9 Check and replace the door seals. Visually check the good state of conservation of protections (fuses, relays, circuit breakers). To verify the characteristics of the fuses Electrical project For checking the settings of overload relays project. Per of circuit breakers checking the settings and features Electrical project. For the protection of indirect (where eist) to verify the correct operation of the overcurrent protection and earth fault using the tool. For the relays and circuit breakers verify proper operation using the tool. Visual verification of the information given on ' switch relay 'min. voltage Verify the integrity 'of the grounding equipment Terminal tightening electrical and strikethrough Check calibration of relays' maimum current For auiliary circuits: 1. Check the tightness of electrical connections of auiliary circuits. 2. Check the integrity of the switches checking with the tester and the actual opening closure. 3. Check the integrity, functionality and the efficiency of switches, buttons, lights, etc. occurring circuits that are enabled under the project. 4. Check the integrity and function of measuring instruments by acting on the voltage switch for voltmeters and
load variation for the ammeters. 5. Check the efficiency of the Auiliary equipment and feeding them where possible, or to perform the check with the tester. N Daily Weekly Monthly Every 3 Check the condition of structures protection against direct contact (screens metal, etc..). Check the equipment inside the program maintenance 7/9 framework rifas. and measure absorption. condensation. For capacitors perform the visual inspection to verify the integrity of the equipment, make the cleaning of the capacitors and check the state of the electrical wiring, isolators and terminal and the status of torque. Check the continuity of conductors ground structures. metal and equipment installed Verify the efficiency of the devices block Check tightening power terminals Continuity groups Visual inspection and cleaning and replacing batteries if necessary. Check autonomy uninterruptible for about one hour Make full charge of the battery rectifier and the group. quotas. Check the battery fluid level if necessary Make sure the plug holes are free from impurities' Check the good condition of the connections electrical Check the density 'of the electrolyte if necessary
F.M. SYSTEM OF LIGHT NORMAL, EMERGENCY AND SAFETY AIR ETRACTOR Checking the status of the lamps both internal and outside of the cab with possible replacement of components that have obvious signs of overheating and / or corrosion and defective lamps or aged. Confirm the lighting of lighting Safety causing a lack of voltage Program maintenance 8/9 normal supply perform a download of the lamps of emergency for a few minutes Driving force for the system test the integrity and with the appropriate tool presence of voltage. (CEE sockets 400 V- 230 V) For the system driving force control the Tightening of the electrical connections and commissioning to the ground. Check for proper operation ejector and make clean the fan Grounding system Every two years, measurements of the ground Verify the integrity 'of links to Earth plate Check tightness of connections in accessible points. Replace parts that show obvious signs of oidation or corrosion. TESTS AND MEASUREMENTS N Daily Weekly Monthly Every 3 1 Every three years, measurements of continuity of all protective conductors and equipotential 2 Every three years, measure insulation resistance 3 Every three years to measure the impedance
Zg of the fault loop at the bottom of circuit, ie at the point farthest from the relative the protective device and verify the relationship according to CEI