Breaker Pole; Repair; Repair Of Surface Damage - ABB VM1 Instruction Manual

7.3.3

Breaker pole

The breaker pole with the vacuum interrupter is maintenance-
free up to the permissible number of operating cycles as sent
down in section 10.1.3.
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 10.1.3:
- When the sum current limit is reached, the complete
breaker poles are to be replaced.
Note:
Dismantling and replacement of the breaker poles should only
be performed by the ABB after-sales service or adequately
trained specialist staff, in particular with regard to the neces-
sity for precise setting.
The following equipment, for example, can be used to check the
vacuum (without dismantling the circuit-breaker):
VIDAR vacuum tester,
from Programma Electric GmbH
Bad Homburg v.d.H. Germany
The following test values have to be set for checking of the inter-
nal interrupter chamber pressure with the VIDAR vacuum tester:
Rated voltage of
the circuit-breaker
12 kV
17.5 kV
24 kV
Testing is to be performed at the rated contact distance in the
OFF condition.
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 VM1 circuit-breaker.
- Earth all poles of the VM1 circuit-breaker on one side.
- Connect the earthed test lead of the VIDAR vacuum tester
conductively to the station earth.
- Connect the high voltage test lead of the VIDAR vacuum
tester with phase L1 of the unearthed pole side and test
the vacuum interrupter chamber with the circuit-breaker
contact gap open. Repeat for phases L2 and L3.
Note:
Connected cables may lead to a "defective" indication on the
vacuum tester as a result of their cable capacitance. In such
cases, the cables are to be removed.
DC test voltage
40 kV
40 kV
60 kV
7.4

Repair

7.4.1

Repair of surface damage:

Circuit-breaker part in general
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 a top coat in the standard colour
RAL 7035 or the relevant special colour.
Sheet steel parts with aluminium-zinc surfaces and chromated
functional 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 lubricant.
Withdrawable circuit-breaker part in general:
- Where required, regrease or thoroughly clean slide plates
and bearings in the panel and regrease them with Isoflex
NB 52 lubricant.
Remove the contact system for thoroughly cleaning as
described below (Figures 9/24 and 9/25):
- Slide the two inner annular tension springs 34.2 facing
the breaker pole to a position beside the other two outer
annual tension springs, thus releasing contact system
34.1, and remove the contact system from contact arm
34.
- The contact pin of the contact system and the slot on the
contact arm are to be cleaned and greased.
- Fit the contact system back to front on the thin end of
arbor 39, and slide it forwards onto the thicker part of
the shank.
- Fit arbor 39 onto the relevant contact arm 34, slide the
contact system 34.1 over onto the contact arm, and
withdraw the arbor.
- Check all contact fingers and annular tension springs for
perfect fit.
Note:
The set installation position of contact arms 34 must not be
changed by the improper use of force.
Instruction manual 504/05 | VM1 Vacuum circuit-breaker 17