54
VM1
- USER MANUAL
—
11. Maintenance
Maintenance operations are aimed at ensuring
trouble-free operation of the apparatus for the
longest possible 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 specification conditions
Repairs:
Measures to be taken to restore
the specification 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 (see par. 11.3.2.).
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 sequence
of operations and on the trips under short-circuit.
Note
For maintenance work, respect the following Standards:
•
the relative specifications indicated in the “Standards and
Specifications” chapter;
•
regulations for safety in the workplace indicated in the “Putting into
service and operations” chapter;
•
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, always
make sure that the circuit breaker is open,
the capacitor 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 VM1 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
> 1600 A and/or
breaking capacity > 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 1,000 handling
operations can be carried out in the case of normal
activation and with regular inspections.
Also see the IEC 62771.200 Standard.
The data on the useful life are in principle applied
to all the components which are not directly
affected by the operator.
The useful life of the manually activated
components (movement of the withdrawable
truck, etc.) can vary according to the type of
handling.
The time intervals and amount of maintenance are
determined by environmental agents, by the
frequency of operation and by the number of trip
operations under short-circuit.
11.1.2 Instructions for capacitor life
The following instructions shall be observed in
order to guarantee the correct function of the
capacitor/s over time:
•
if the capacitor is kept on stock or warehouse for
more than 2 years without power supply feeding,
it is required to replace the capacitor.
•
if the capacitor is kept on stock or warehouse for
more than 1 year and less than 2 years in/out of
temperature tolerance range (-25 °C to +55 °C), the
reconditioning procedure of the capacitance by
reforming must be executed.
•
it is recommended to replace the capacitor every
10 years for both normal and stressed use (10000
operations) and for conditions of temperature
within-25 °C to +55 °C.
•
after 15 years the capacitor must be replaced.
•
for applications in which the capacitors are
installed in parallel (two, three or more), they
should belong to the same production batch
hence to have the same batch number
YYWWXXXXX (QR-CODE).
Summary of Contents for VM1
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