ABB MNS R - Maintenance Program

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1TTS900001M0902
GENERAL INSPECTIONS
1. Circuit breakers connections
(cables or busbars)
• Contactsurfacesblackening
• Loosenedscrews
• Cleanwithclothandsolvent
• Tightenaccordingtothe
tightening torque indicated in
Appendix A.
2. Earth busbar joints and related
connections
• Copperoxide • Removetheoxidebymeans
of a file or an emery cloth
• Cleanwithclothandsolvent
• Loosenedscrews Tighten according to tightening
torque
3. Insulating busbar keepers Dust Remove the dust by means of a
vacuum cleaner
• Crack
• Dischargemarks
Replace the damaged busbar
keepers (address to ABB Sace)
4. Ventilation grids Dust or dirt Remove by means of a vacuum
cleaner
5. Circuit breakers See the related installation,
operation and maintenance
instructions
Carry out the suggested
maintenance procedures
6. Main power feeding busbars,
distribution busbars, connections
between busbars and circuit breakers
Discharge or smoke marks Clean with solvent. If necessary
replace the damaged part
(address to ABB Sace)
INSULATION RESISTANCE INSPECTION
Measure the insulation resistance in accordance with the same procedures indicated for the start. Measured
values should not be very different from those detected during the start. If the insulation level is notably less,
carry out voltage tests. It is better to perform the insulation resistance measurement before the voltage tests,
and in case of insulation resistance decrease it is necessary to search the crush point.
5.3 Maintenance Program