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All the
measures incorporated should achieve repair times just minutes
and MTBF more than years. The most important protection
functions (overcurrent and overspeed) are
also duplicated hard-wired devices acting
as back-up for the software protection
functions. Tests are performed various stages
during production addition the extensive
final tests (heat run, combined, and burn-in
tests are conducted request).
Supply
transformer:
Oil temperature and
level and Buchholz
in the case oil-
immersed types,
respectively winding
temperature the
case dry types.Protection and diagnostics
The protection and supervisory functions
ensure that the mechanical and thermal
operating limits the drive are not exceeded. leading supplier drive
systems, ABB achieves the highest reliability
by ensuring that complies with the quality
standards and procedures specified ISO
9001.
Numerous protective and supervisory
functions are available. For example, thyristor can be
replaced without having interrupt the cooling water circuit.
Motor:
Overvoltage, undervoltage, stalled rotor,
winding and bearing temperatures, over-
speed and set
speed deviation. Trips and alarms are transmitted
to the relevant devices shut down or,
should become necessary, trip the drive
completely.
Converter:
Supply over and
undervoltage,
overcurrent, ground
fault, failure of
auxiliaries, cooling
water temperature,
level, flow and
conductivity, respec
tively air flow the
case air-cooled
units, and excitation
and control system
failure. cooling pump or
fan and essential parts the control system)
can provided which enormously increases
reliability and availability while enabling
maintenance intervals extended to
4 years and more.
The following are the minimum included with
the standard MEGADRIVE-LCI.
Attention has also been paid the simple replacement all
components,units and assemblies.g.
Reliability must!
Reliability and availability are the utmost
importance power plants and industrial
processes. Redundancy
of crucial components (e. Should the drive fail spite all these
precautions, fault location and corrective action are made easy by
the failure indication system which points the precise component.
7
. Faults are displayed plain
language the control panel the door of
the control cubicle and any remote control
panel with clear indication the first fault.
They are implemented the application
program running the micro-processor of
the programmable high-speed controller and
their signals are evaluated the diagnostic
system.
Where appropriate, functions are physically isolated from each
other the interest greater reliability.
Also components are conservatively rated and more than adequate
safety margins are allowed.
A special design feature MEGADRIVE-LCI its ability ride
through brief supply interruptions that most cases they pass
unnoticed the process
