ABB VD4 Series Instruction Manual - page 33
Instruction manual 534/01 | VD4 Vacuum-circuit-breaker 33
8.3.3 Breaker pole
The breaker pole with the vacuum interrupter is maintenance-
free up to reaching the permissible number of vacuum inter-
rupter operating cycles in accordance with section „Permissi-
ble number of vacuum interrupter switching operations“.
The working life of the vacuum interrupter is defined by the
sum current limit corresponding to the equipment data in
individual cases in accordance with section „Permissible num-
ber of vacuum interrupter switching operations“:
- When the sum current limit is reached, the complete
breaker poles are to be replaced.
Note:
Dismantling and Replacement of the complete breaker poles
should only be carried out by ABB after-sales service person-
nel or by specially trained personnel, particularly as proper
ad just ment is necessary.
For testing the vacuum without dismantling the circuit-breaker
you may use:
- Vaccuum tester VIDAR, from Programma Electric GmbH,
Bad Homberg v.d.H.
The following test values have to be set for checking of the
internal interrupter chamber pressure with the VIDAR vacuum
tester:
Rated voltage of
DC test voltage
the circuit-breaker
24 kV
60 kV
Testing must always be performed with the device switched
off:
- 24 kV: with rated contact distance
Procedure for vacuum interrupter testing for stationary
mounted switching devices:
- Isolate and secure the working area in accordance with the
Safety Regulations to DIN VDE / IEC.
- Open the circuit-breaker.
- Earth all poles of the circuit-breaker on one side.
- Connect the earthed test lead of the the VIDAR vacuum
checker conductively to the station earth.
- Connect the high voltage test lead of the VIDAR vacuum
checker with phase L1 of the unearthed pole side and test
the vacuum interrupter chamber with the circuit-breaker con-
tact gap open. Repeat for phases L2 and L3.
Note:
Connected cables may lead to a “detective“ indication on the
vacuum checker as a result of their cable capacitance.
In such cases, the cables are not be removed.
8.4
Repair
8.4.1 VD4 circuit-breaker run-on block
In case of any irregularity in the area of the inner control
mechanism and of the charging function of the stored-energy
spring mechanism, the run-on block disables the immediately
subsequent switching operation.
This is a protective measure to prevent damage to the circuit-
breaker
Release of the run-on block is described in instruction manual
BA 383/E.
8.4.2 Replacement of circuit-breaker parts and accesso ries
Only remove and reassemble circuit-breaker parts and accesso-
ries when the breaker has been switched off and the working
area is to be isolated and secured against reclosing. The
spring energy storage mechanism must be discharged.
All supply voltage sources must be disconnect ed and secured
against reclosing during the removal and installation work.
8.4.3 Touch up of surfaces
- Sheet steel parts, painted:
- Remove rust, e.g. with a wire brush.
- Grind off paint coat and degrease.
- Apply anti-rust primer and top coat.
- Use top coat paint in the standard colour RAL 7035.
- Sheet steel parts, with zinc surface and passivated func-
tional parts:
- Remove white rust with a wire brush or cleaning pad
(e.g. Scotch-Brite white).
- Remove loosely adhering particles with a dry cloth.
- Apply zinc spray or zinc dust primer.
- Functional parts, phosphated:
- Remove rust with a wire brush or cleaning pad
(e.g. Scotch-Brite white).
- Clean with a dry cloth.
- Grease with Isoflex Topas NB 52.
8.4.4 Circuit-breaker in general
- Check that the bolt connections at the contact points in
the busbar system are tight, and that the isolating contact
system functions correctly.
- Regrease the contact points and mechanism of the with-
drawable part insertion system as necessary, or, when
lubrication is inadequate or missing, thoroughly clean the
areas concerned and regrease with Isoflex Topas NB 52
lubricant.
- Where required, regrease or thoroughly clean slide plates
and bearings in the panel and regrease them with Isoflex
NB 52 lubricant.
8.4.5 Replacement of contact systems
(Cover illustration of „Maintenance“ section)
Remove the contact system for thoroughly cleaning as descri-
bed below (Figures):
- Slide the two inner annular tension springs facing the
breaker pole to a position beside the other two outer an-
nual tension springs, thus releasing contact system, and
remove the contact system from contact arm.