34
5.2.10. Repairs
Replacement of spare parts and accessories must only
be carried out by Abb personnel or suitably qualified and
specially trained personnel.
Always work with the circuit-breaker open and locked so that
it cannot be closed again, with the work area insulated and
made safe.
The drive springs must be discharged.
All power supply sources must be disconnected and made
safe against any reclosing during removal and installation
work.
SHOuLD MAINTENANCE bE
CARRIED OuT by THE CuSTOMER'S
PERSONNEL, RESPONSIbILITy FOR THE
INTERVENTIONS REMAINS wITH THE
CuSTOMER.
THE REPLACEMENT OF PARTS NOT
INCLuDED IN THE "LIST OF SPARE
PARTS/ACCESSORIES" MuST ONLy bE
CARRIED OuT by Abb PERSONNEL.
IN PARTICuLAR:
- COMPLETE POLE wITH buSHINGS/
CONNECTIONS
- ACTuATOR
- TRANSMISSION SySTEM.
CAUTION
5.2.8. Servicing details
•
If provided, turn off the spring charging motor power supply
and manually discharge the operating mechanism springs
by closing and opening the circuit-breaker.
•
Replace parts subject to high climatic or mechanical
stresses (contact an Abb service centre).
note
These operations can only be carried out by Abb personnel
or suitably qualified and specially trained personnel.
5.2.9. vacuum interrupters
The vacuum interrupters are maintenance-free up to the
maximum number of electrical operations.
The operating life of the vacuum interrupter is defined by the
sum of the ultimate currents corresponding to the specific
type of interrupter: when the sum of the ultimate currents is
reached, the complete VI must be replaced, for electrical life
ask to Abb.
note
Dismantling and replacement of the interrupter assembly
can only be carried out by Abb personnel or by qualified
and specially trained personnel, especially for the necessary
adjustments.
To carry out the interrupter test use the VIDAR vacuum
tester, of the Electric GmbH, bad Homberg v.d.H. company
Programme.
To check vacuum tightness of the interrupter, the following
test values must be set on the VIDAR tester:
Rated voltage of the circuit- breaker
dC test voltage
15 kV
40 kV
The test must always be carried out with the circuit-breaker
open with the contacts at the nominal distance.
Procedure for testing the degree of vacuum of the interrupter:
– cut off the voltage in the working area and make it safe
in accordance with the safety regulations specified in the
ANSI/NFPA 70/NEC Standards;
– open the circuit-breaker;
– earth a terminal of each circuit-breaker phase;
– connect the earth terminal of the VIDAR tester to the circuit-
breaker structure;
– connect the high voltage terminal of the VIDAR tester to the
terminal not connected to earth of the interrupter (L1 phase)
and carry out the test. Repeat the test for phases L2 and L3.
note
The tester connection cables can produce an indication due
to the capacitive effect. In this case the cables must not be
removed.
