Operating Life; Procedure For Discharging The Capacitor/S; Mechanism And Transmission System - ABB VM1 Installation And Service Instructions Manual

8.3. Operating life

All vacuum circuit-breakers are characterised by simple,
sturdy construction and long useful life. Frequent operation of
the service and shortcircuit 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, maintenancefree 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
- up to 50,000 operating cycles for all the circuit- breakers
with 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 1000 handling operations can be
carried out in the case of normal activation and with regular
inspections.
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.
8.4. Procedure for discharging the
capacitor/s
Before accessing the circuits in the control box, it is
compulsory to make sure that the capacitor is discharged.
Even without auxiliary power supply, more than about ten
minutes are needed to completely discharge the capacitor/s.
Activate the circuit-breaker.
Disconnect the power supply voltage.
Operate the circuit-breaker by pressing the pushbuttons with
the following cycle: O-C-O.
The luminous "Ready" signal turns off when the operation
cycle has been completed, i.e. when the circuit-breaker is no
longer ready for operations.
After 10 minutes have passed, the capacitor voltage drops to
a value of less than 15 V.
It is avalaible on request the Rapid Discharging Device that
allows the waiting time to be reduced to just one minute and
guarantees safe access to the circuits which might be live.
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8.5. Mechanism and transmission
system
The mechanism requires visual inspection of hardware,
lubrication and operation during routine inspection.
Remove the front cover by unfastening its screws and
correct any loose or missing hardware.
Always lubricate the working surface of the moving parts.
Verify lubrication on the connections of the actuator and
lever arm. Remove any grease on the circuit-breaker frame.
Use only ISOFLEX TOpas NB52 (ABB GCE007249P0100/PL
CRM). If the grease becomes caked and dirty, remove with a
clean cloth and reapply lubrication.
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.
high SPeed MeChaniCal PaRtS.
SeRiouS injuRy May oCCuR.
keeP handS and toolS
CleaR of the MeChaniSM
duRing oPening and CloSing
oPeRationS and anytiMe
the CaPaCitoRS oR oPening
SPRingS aRe ChaRged. befoRe
MaintenanCe veRify "Ready"
laMP iS off. oPening SPRingS
aRe alwayS ChaRged when
the CiRCuit-bReakeR iS
CloSed.
dangeR