Periodic Checking - ABB VD4 Addendum Manual
Vacuum cb cradle solutions for retrofitting sf6 gas cb hpa36
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Also See for VD4:
- Installation and service instructions manual (73 pages) ,
- Product manual (56 pages) ,
- Instruction manual (44 pages)
Table of Contents
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Periodic checking
CAUTION
Before carrying out any operation, make sure
that the operating mechanism springs are
discharged, and that the apparatus is in the
open position.
General
During normal service, the circuit-breakers are
maintenance free.
Table 2.1
Subject of the
Procedure
inspection
Medium voltage circuits
1
Insulation
resistance
With a 2500 V megger, measure the insulation resistance between phases
and exposed conductive part of the circuit.
Auxiliary circuits
With a 500 V megger (installed equipment permitting) measure the
insulation resistance between the auxiliary circuits and the exposed
conductive part.
2
Auxiliary
Check that the connections to the control circuit are correct; proceed with
circuits
relative supply.
3
Manual
Carry out a few closing and opening operations. N.B. Supply the u/v
operating
release and the locking magnet on the operating mechanism at the relative
mechanism
rated voltage
4
Motor
Supply the geared motor for spring charging at the relative rated voltage.
operator*
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)
5
Under voltage
Supply the undervoltage release at the relative rated voltage and carry out
release*
the circuit-breaker closing operation. Disconnect the power supply to the
release.
6
Shunt opening
Close the circuit-breaker.
release and
Supply the shunt opening release at the relative rated voltage.
additional
shunt opening
release*
7
Shunt closing
Open the circuit-breaker. Supply the shunt closing release at the relative
release*
rated voltage.
8
Key lock*
Open the circuit-breaker Turn the key and remove it
Attempt the circuit-breaker closing operation
Insert the key again and turn it 90°
Carry out the closing operation
9
Locking
With the circuit-breaker open, springs charged and locking electromagnet
electromagnet
not supplied, attempt to close the circuit-breaker both manually and
(RL1)*
electrically.
10 Auxiliary
Insert the auxiliary contacts into suitable signaling circuits. Carry out a few
contacts in the
closing and opening operations.
operating
mechanism
11
Racking device
With closed circuit-breaker try to operate the lever.
with lever on
the unit
The frequency and sort of inspections basically depend on
the service conditions. Various factors must be considered:
frequency of operations, interrupted current values, relative
power factor and the installation ambient.
The following paragraph gives the checking program table,
showing the relevant time intervals.
As far as the time interval between these operations is
concerned, it is advisable to comply with the specifications
given in the table, at least during the first check. On the
basis of the results obtained during the periodic
inspections, set the optimal time limits for carrying out the
operations listed in table 2.2 (see page 16).
Positive check
The insulation resistance should be a few MΩ
and, in any case, constant over time.
The insulation resistance should be at least 50
MΩ and, in any case, constant over time.
Normal switching and signaling.
The operations and relative signals occur
correctly.
The springs are charged correctly. The signals are
correct.
The geared motor cuts off when the springs are
charged.
The geared motor recharges the springs after
each closing operation.
The circuit-breaker closes correctly. The signals
are correct.
The circuit-breaker opens. The signal changes
over.
The circuit-breaker opens correctly. The signals
are correct.
The circuit-breaker closes correctly. The signals
are correct.
Neither manual nor electric closing takes place.
Both electric and manual closing take place
correctly; in this position the key cannot be
removed.
Closing is not possible.
Signals occur correctly.
The lever cannot be operated and the racking-out
are not possible.
17
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