Maintenance; General - ABB VM1 Instruction Manual

7

Maintenance

Maintenance serves to preserve trouble-free operation and
achieve the longest possible working life of the switchgear. In
accordance with DIN 31 051 and IEC 61208, it comprises the
following closely related activities:
Inspection: Determination of the actual condition
Servicing: Preservation of a functional condition
Repair: Measures to restore the functional condition
7.1

General

All VM1 vacuum circuit-breakers are characterised by a simple
and robust construction. They have a long life expectancy.
There is no adverse effect on the vacuum, even from frequent
switching of operating and short-circuit currents.
The typical life expectancy of a VM1 vacuum circuit-breaker is
determined by:
- Maintenance-free, potted vacuum interrupters for up to
30,000 mechanical operating cycles.
- Magnetic actuator mechanism, maintenance-free under
normal service conditions:
- up to 100,000 operating cycles for all breakers with a
breaking current ≤ 25 kA and a rated current ≤ 1250 A,
- up to 50,000 operating cycles for all breakers with a
rated current of ≥ 1600 A,
- up to 50,000 operating cycles for all breakers with a
breaking current ≥ 31.5 kA.
- Maintenance-free control module with sensors and without
auxiliary switches.
- Auxiliary switch ON/OFF position signalization (optional) up
to 30,000 switching cycles.
- Withdrawable part: With careful operation and appropri-
ately performed inspection work, up to 1000 movement
operations can be achieved.
See also IEC 60298.
Concerning detailed information about the maintenance of the
VM1 circuit-breaker please contact the ABB service.
The service life data fundamentally apply to all components
which are not directly influenced by the operator.
Components operated manually (movement of the withdraw-
able part, etc.) may deviate, depending on how they are
handled.
The servicing intervals and scope are determined by the envi-
ronmental influences, the switching frequency and the number
of short-circuit breaking operations.
Note:
The following must be observed for all maintenance work:
- The relevant specifications in section 1.2.2.
- Notes on safety at work in section 6.1
- Standards and specifications in the country of installation.
Maintenance work may only be performed by fully
trained personnel, observing all the relevant safety
regulations. It is recommended that ABB after-sales
service personnel should be called in, at least during
the performance of servicing and repair work.
While the work is in progress, and if the work permits,
all supply voltage sources must also be disconnected
and secured to prevent re-connection.
Note:
In order to prevent accidents (particularly injury to
hands!) extreme care should be taken during all repair
work on the operating mechanism, especially with
front plate 1.1 removed.
The energy of the storage capacitor can be released
uncontrollably during incorrect handling!
Procedure for capacitor discharge:
1. Switch circuit-breaker on.
2. Switch supply voltage off (m.c.b.).
3. Switch circuit-breaker by pressing push-buttons 3
and 4 with cycle: OFF/ON/OFF.
The "READY" lamp will go out when this switch-
ing cycle is completed, i.e., the switch is no longer
ready for switching operations.
4. After the following waiting times the storage capac-
itor will have discharged down to lower than 15 V:
- after approx. 4 minutes for breaking currents up
to 25 kA
- after approx. 8 minutes for breaking currents of
31.5 kA and above.
Where appropriate in individual cases, further
information can be found in the technical docu-
mentation appurtenant to the switchgear system
(e.g. agreed special operating conditions)
in addition to this operating manual.
Instruction manual 504/05 | VM1 Vacuum circuit-breaker 15