ABB VM1 Installation And Service Instructions Manual page 55

M E D I U M V O LTA G E P R O D U C T S
11.1.3. Procedure for discharging the capacitor/s
Activate the circuit breaker.
Disconnect the power supply voltage.
Operate the circuit breaker by pressing the
pushbuttons with the following cycle: O-C-O.
The luminous "Ready" signal turns off when the
operation cycle has been completed, i.e. when the
circuit breaker is no longer ready for operations.
After 8 minutes have passed, the capacitor
voltage drops to a value of less than 15 V.
If required in specific cases, further information
can be obtained from the technical
documentation regarding the switching apparatus
(e.g. any special service conditions agreed on), as
well as from this instruction manual.
11.1.4. Drive with magnetic actuator
The drive with magnetic actuator is maintenance-
free up to the number of operation cycles
indicated in paragraph 11.1.1.
11.2. Inspections and functional
tests
11.2.1. Interruption devices in general
• Carry out regular inspections to check that the
interruption devices are in good condition.
• Inspection at fixed intervals can be waived when
the apparatus is permanently monitored by
qualified personnel.
• Above all, the checks must include a visual
inspection to check for any contamination, traces
of corrosion and electrical discharge phenomena.
• Carry out more frequent inspections when there
are unusual operating conditions (including
adverse climatic conditions) and in the case of
environmental pollution (e.g. heavy contamination
or an atmosphere with aggressive agents).
• Visual examination of the isolating contacts.
Turning the system of contacts alternately is
recommended, in order to keep the internal
surface of the contact areas clean. The contact
areas must be cleaned if there are signs of
overheating (discoloured surface) (also see the
paragraph on "Repairs").
• If any anomalous conditions are found,
appropriate servicing measures must be taken
(see the paragraph on "Servicing).
11.2.2. Circuit breaker pole
No check is required apart from what has already
been specified in par. 10.3.
11.3. Servicing
11.3.1. Interruption devices in general
If cleaning is found to be necessary during the
inspections, as specified in par. 10.3., use the
following procedure:
• insulate the working area and make it safe by
following the safety regulations specified in the
IEC/DIN VDE Standards.
• general cleaning of the surfaces:
- dry and eliminate any light deposits of dirt using
a soft dry cloth;
- more resistant deposits of dirt can be removed
using a slightly alkaline household cleanser or
Rivolta BWR 210 type detergent.
• cleaning the insulating surfaces and conductive
components:
- light dirt: with Rivolta BWR 210 detergent;
- resistant dirt: with cold 716 type detergent.
After cleaning, rinse thoroughly with clean water
and dry carefully
Note
Only use halogen-free detergents and never trichloroethane,
trichloroethylene or carbon tetrachloride!
11.3.2. Actuator and transmission system
A functional test of the drive must be carried out:
• when the number the number of operating cycles
indicated has been exceeded, or
• during maintenance operations.
Before carrying out the functional test, open the
circuit breaker and
• take it to the test position (withdrawable circuit
breaker) or
• insulate the working area and make it safe in
conformity with the safety rules and according to
the regulations in force (fixed circuit breakers)
• follow the procedure for discharging the capacitor
• carry out a visual inspection of the state (removing
the front panel), e.g. of:
- lubrication of the ball bearings
- the operation counter
- assembly of the sensors
- the position indicator.
Functional test:
• Connect the power supply voltage.
• Carry out several no-load operations. This test
particularly applies to circuit breakers which are
rarely activated under normal conditions.
To check the capacitor, carry out a rapid O-C-O
cycle of operations of the circuit breaker, by
pressing the pushbuttons on the front of the
circuit breaker in rapid succession.
• The LEDs on the inductive sensors are activated as
soon as the circuit breaker has reached the closing
and opening limit positions
Note
These operations can only be carried out by ABB personnel or suitably
qualified and specially trained personnel.
55 55