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11. Maintenance
Maintenance operations are aimed at keeping the apparatus working properly for the longest possi-
ble time.
In accordance with what is specified in the IEC 61208 / DIN 31 051 Standards, the following
operations must be carried out.
Inspection:
Determination of the actual conditions
Servicing:
Measures to be taken to maintain the specific conditions
Repairs:
Measures to be taken to restore the specific conditions.
11.1. General
Vacuum circuit-breakers are characterised by simple, sturdy construction and long life.
The drive is maintenance-free for its whole operating life and only requires functional inspections.
The vacuum interrupters are maintenance-free for their whole operating life.
Vacuum interruption does not produce harmful effects even when there are frequent trips at the
rated and short-circuit current.
The servicing interventions and their aim depend on the environmental conditions, on the se-
quence of operations and on the trips under short-circuit.
For maintenance work, respect the following Standards:
– the relative specifications indicated in para. 5.1 "Standards and Provisions" chapter;
– regulations for safety in the workplace indicated in the "Putting into service" chapter 10 and para.
10.2 "Circuit-breaker operations";
– regulations and specifications of the country where the apparatus is installed.
The maintenance operations can only be carried out by trained personnel who respect all the
safety regulations. Furthermore, is recommended that ABB service personnel should be called in,
at least to check the service performances, and for any repair work.
During maintenance work, turn the power supply off and put the apparatus under safe conditions.
Before carrying out any operations, make sure that the circuit-breaker is open, the capaci-
tor discharged and that it is not supplied (medium voltage circuit and auxiliary circuits).
11.1.1. Operating life
All vacuum circuit-breakers are characterised by simple, sturdy construction and long useful life.
Frequent operation of the service and short-circuit currents does not negatively affect the degree
of vacuum of the interrupters.
Typical useful life expectancy of a eVM1 vacuum circuit-breaker is determined by the following
factors:
• embedded vacuum interrupter, maintenance-free up to 30,000 mechanical operating cycles.
• drive with magnetic actuator, maintenance-free under normal service conditions
– up to 100,000 operating cycles for all the circuit-breakers with breaking capacity up to 25 kA
and rated current up to 1250 A
– up to 50,000 operating cycles for all the circuit-breakers with rated current d" 1600 A and/or
breaking capacity e" 31.5 kA
• control module and sensors, maintenance-free (excluding the auxiliary contacts)
• indication of ON/OFF position of the auxiliary contacts (optional) up to 30,000 operating cycles
• withdrawable truck: up to 1000 handling operations can be carried out in the case of normal
activation and with regular inspections.
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