ABB HD4/R, Installation And Operating Instructions Manual

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9. Routine inspections
Before proceeding with any operation,
always make sure that the springs of the
operating mechanism are discharged and
that the apparatus is in the open position.
9.1 General information
During normal service, the circuit-breakers are maintenance-
free. Any interventions required basically depend on the se-
verity of the service conditions, i.e. to various different factors
such as the frequency of the operations, the interrupted current
values, the relative power factor and the installation site.
For precautionary reasons, an inspection schedule is given in
the table in the following section, along with the frequency with
which the equipment must be checked.
As far as this latter is concerned, it is advisable to comply with
the specifications in the table, at least during the first inspec-
tion.
Optimal time limits for carrying out successive operations can
be established on the basis of the results obtained during the
routine inspections.
9.2 Inspection schedule
Inspection Frequency Criteria
1 Perform five mechani-
cal closing and opening
operations. Once a year The circuit-breaker must
function normally, without
stopping in intermediate
positions
2 Visual inspection of the
poles (resin parts) Once a year
or after
every 5,000
operations The resin parts must be free
from any built-up dust, dirt,
cracks, discharges or traces
of surface discharges
3 Visual inspection of the
operating mechanism
and transmission Once a year
or after
every 5,000
operations The elements must not be
deformed in any way.
Screws, nuts, bolts, etc.,
must be tight
4 Measurement of the
insulation resistance Every 5
years or after
every 5,000
operations See sect. 8.1 point 1
5
Checking interlock
operation Every 5
years or after
every 5,000
operations The interlocks provided must
function correctly
Warning!
Contact the ABB Assistance Service and have the circuit-
breaker completely overhauled after 10,000 operations or after
10 years.
9.3 Troubleshooting
The shunt opening and/or shunt closing release remains energized
Faults
The shunt opening and/or shunt closing undervoltage releases are insufficiently energized
Release coils interrupted or burnt, gearmotor winding inerrupted
The circuit-breaker fails to open
The circuit-breaker fails to close
Flashovers
Possible causes Inspections and remedies
•
Operating or accept contacts locked closed
Check the condition of the contacts in series with the
release
• • •
Supply votage of the auxiliary circuits too low
Measure the voltage: it must not be less than 85% of the
rated voltage
• •
Supply voltage different from the value indicated on the
nameplate for these releases Check the voltage indicated on the nameplate of the
releases
• • • • •
Faulty switching circuit
Check the connections, fuses, interlocks, protection
switches and accept contacts
• • •
Loose wire clamping screws Make sure that the wire clamping screws are tight
• • • • •
Incorrect electrical connections in the power supply circuit Check the connections with the relative functional diagram
• • •
Release coils interrupted Replace the coils
•
Conductive dust on the insulating parts
Clean carefully. Check the insulation resistance with a 2500
V Megger (sect. 8.1.)
• • •
Operating mechanism locked
Operate in the manual mode. Contact ABB if the fault
persists
•
Key not inserted in the key lock of the operating mechanism Insert and turn the key
•
Undervoltage release not energized Check the relative supply circuit
•
Shunt opening release remains energized
Check the supply circuit and the relative contact in series
with the release coil