37
1
Medium voltage circuit
With a 2500 V megger, measure the insulation resist-
ance between the phases and the exposed conduc-
tive part of the circuit.
Auxiliary circuits
With a 500 V megger (if the apparatus installed allows
this), measure the insulation resistance between the
auxiliary circuits and the exposed conductive part.
Check that the connections to the control circuit are
correct: proceed at the relative power supply.
Carry out a few closing and opening operations (see
chap. 6). N.B. Supply the undervoltage release and
the locking magnet on the operating mechanism at
the relative rated voltage (if provided).
Supply the spring charging geared motor at the rela-
tive rated voltage.
Carry out a few closing and opening operations.
N.B. Supply the undervoltage release and the locking
magnet on the operating mechanism at the relative
rated voltage (if provided).
Supply the undervoltage release at the relative rated
voltage and carry out the circuit-breaker closing
operation.
Cut off power to the release.
Close the circuit-breaker and supply the shunt open-
ing release at the relative rated voltage.
Open the circuit-breaker and supply the shunt clos-
ing release at the relative rated voltage.
The insulation resistance should be at least 50 Mohm
and in any case constant over time.
The insulation resistance should be a few Mohm and
in any case constant over time.
Operations and signals normal.
The operations and the relative signals take place
normally.
The springs are charged normally.
The signals are normal.
With the springs charged, the geared motor stops.
The geared motor recharges the springs after each
closing operation.
The circuit-breaker closes normally.
The signals are normal.
The circuit-breaker opens.
The signal changes over.
The circuit-breaker opens normally.
The signals are normal.
The circuit-breaker closes normally.
The signals are normal.
Insulation resistance.
Auxiliary circuits.
Manual operating mechanism.
Motor operator (if provided).
Undervoltage release (if provided).
Shunt opening release and addi-
tional shunt opening release (if pro-
vided).
Shunt closing release (if provided).
8.
Putting into service
8.1. General procedures
All the operations regarding putting into
service must be carried out by ABB per-
sonnel or by suitably qualified customer
personnel with in-depth knowledge of
the apparatus and of the installation.
Should the operations be prevented, do
not force the mechanical interlocks and
check that the operating sequence is
correct.
The operating forces which can be ap-
plied for racking-in withdrawable circuit-
breakers are indicated in paragraph 7.5.
ITEM INSPECTED
PROCEDURE
POSITIVE CHECK
2
3
4
5
6
7
Before putting the circuit-breaker into service,
carry out the following operations:
– check tightness of the power connections to
the circuit-breaker terminals;
– establish the setting of the primary electronic
overcurrent release (if provided);
– check that the value of the power supply volt-
age of the auxiliary circuits is between 85%
and 110% of the rated voltage of the electrical
accessories;
– check that no foreign bodies, such as bits of
packing, have got into the moving parts;
– check that there is a sufficient exchange of air
in the installation place to avoid overtempera-
tures;
– also carry out the checks indicated in table T3.
T3
Summary of Contents for VD4 12
Page 1: ...VD4 Installation and service instructions 12 24 kV 630 2500 A 16 31 5 kA ...
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Page 46: ...44 Notes ...
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