Power Supply Redundancy
Each controller has its own power supply.
In case of a failure of some power supply unit, the system will
tolerate it. The power supply for the valve electromagnet
is hot backed-up by a second power supply unit.
Diagnostics
Valve Diagnostics
The system monitors several temperature values at specific points,
which indicate for leakage presence. The valve position
indication value is also monitored. Should some of these
values become bigger than the preset values, an alarm signal together
with a specific signal are generated.
Valve Electromagnet
Diagnostics
The system monitors the availability of the control signal on
the electromagnet terminal. Option: The system can sense
the current through the electromagnet.
Qualification
The system is qualified as
a Safety Class 1E. The system meets the requirements of
the standards IEEE323 - Standard for Qualifying Class 1E Equipment
for Nuclear Power Generating Stations, IEEE 344 - Recommended
Practice for Seismic Qualification of Class 1E Equipment for Nuclear
Power Generating Stations. The system is rugged
to withstand harsh seismic requirements and has passed the tests
successfully. The test results are available for review.
Advantageous Selfdiagnostics
The system is capable of localizing a fault on
an unit level. By means of the LCD display of the Configuring
Unit (device for setting up the preset values and reading
of diagnostic messages) the maintenance personnel can get information
about the status of every controller, every analogue input, transducer,
output relay and the status of the output cabling to the electromagnet
of the valve. By simple removal, the faulty unit can be replaced
with a spare one. ON LINE Testing Due to the
fact that the protective action of the valve may not take place
for a long period of time, the system is capable of testing the
availability of the OUTPUT switch on line. For this purpose, the
designated specialist can implement a simple procedure by means
of the Configuring Unit.
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Availability and Reliability
The Calculated Availability,
based on Mean Time to Repair- 48h, is 0,999913227.
The careful selection of the components, the high professional
procedures of producing and treatment of the subassemblies and
systems are the guarantee of their high reliability.
Quality Assurance
The Design, Development and Production
of the products of the Company are based on the requirements of
ISO 9001. The careful selection, shock-in and burn
treatments of the components, the active subcontractor selection
strategy, as well as an ingenious design, ensure the conformance
of the systems to the very high requirements of the nuclear applications.
Ten years support and upward upgrading
and compatibility are a basic guideline of the Systems design
and development.
Some key electrical characteristics
The systems meet the requirements of the following
standards:
( 
Influence of Electromagnetic Field, 50 Hz
-withstands 100A/m continuously; -withstands 1000A/m for
a period of 3s.
(
Immunity on repetitive electrical fast transients:
Power circuit- withstands 4kV; Analog I/Os- withstand
2kV; Discrete I/S- withstands 1kV Immunity to
Electrostatic Discharges; -withstands Contact Discharges-
8kV; -withstands Air discharges- 12kV.
(
50746-95) Stability on Power Supply
Dips and Interruptions: The system withstands
Power Interruption: 500mS; Dips: -30% continuously
+20% continuously. Custom design and flexibility
The systems can be adjusted to the customer's requirements, without
sacrificing the quality.
is trademark os Echelon Corporation registeredin
the Unated States and other countries.
Reference for this product
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