Stored-Energy Spring Mechanism; Scope Of Functional Testing; Breaker Pole; Run-On Block - ABB VD4X Instruction Manual

M A I N T E N A N C E

5.2.2 Stored-energy spring mechanism

Functional testing of the operating mechanism
is to be performed:
• after 5,000 operating cycles or
• during servicing work as set out in section
"Inspection, switching devices in general"
Prior to functional testing, switch the breaker
off and isolate the outgoing feeder.
Note
Isolate and secure the working area in accordance
with the safety regulations specified by DIN
VDE/IEC.

Scope of functional testing

• Perform several switching operations under
no-load, above all with circuit-breakers seldom
operated in normal service
• Switch off the charging motor (if fitted) and
discharge the spring energy storage
mechanism by ON/OFF switching operations
• Examine visual the condition of the lubrication
on rotary bearings, sliding surfaces, etc
• Check the proper mechanical/electrical sequence
of the individual functions

5.2.3 Breaker pole

No inspection of the breaker pole above and
beyond the stipulations of section "Inspection,
switching devices in general" is necessary.
5.3 Servicing
5.3.1 Switching devices in general
All parts which are located within the gas
compartment and are therefore inaccessible
require no maintenance.
5.3.2 Stored-energy spring mechanism
Servicing of the operating mechanism is to be
performed after 10,000 operating cycles.
Prior to servicing, open the circuit-breaker,
isolate and secure the outgoing feeder to
prevent reconnection.
Scope of servicing
• Switch off the charging motor and release the
spring energy storage mechanism by closing
and opening the breaker
• As a precaution, replace parts subject to high
climatic and mechanical stresses
• For replacement of highly stressed
parts, release the pretension of the
spiral spring, noting the
pretensioning dimension. Take care
when handling springs
• Relubricate pawls, support shafts,
sliding and rotating bearing surfaces.
Lubricant: Isoflex Topas NB 52
• Check the fit of fasteners (e.g. locking
pins) in cranks, pins, bolts etc. Check
the tightness of fastening bolts
• Always replace any spring lock
washers, split pins and other
fasteners removed during the work
with new parts when reassembling
the equipment
• Check the general condition of the
operating mechanism and recharge
the spring to the pre-tensioning
dimension noted
• Perform comprehensive mechanical
and electrical functional tests
(Observe the setting instructions)
Note
Above mentioned work may only be performed
by servicing personnel from ABB or adequately
trained specialist staff.
5.3.3 Breaker pole
The breaker pole with the vacuum interrupter is
maintenance-free up to the permissible number
of operating cycles as sent down in section
"Permissible number of vacuum interrupter
switching operations":
• When the permissible number of operating
cycles as a function of the breaking current has
been reached, the vacuum interrupters are to
be replaced (see section 2.3)
Note
The above activities may only be performed by
servicing personnel from ABB or adequately
trained specialist staff, as they require work on
the circuit-breaker itself.
5.4 Repair

5.4.1 Run-on block

Should irregularities occur in the area of the
internal control mechanism and the charging
function of the spring energy storage mechanism,
a run-on block blocks the next closing operation
in sequence.
This is a protective function to prevent damage
to the circuit-breaker.
Release of the run-on block may only be performed
by servicing personnel from ABB or adequately
trained specialist stuff.
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