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DESCRIPTION
The Voltage
Measurement and Protection Relay (VMPR) has been designed to
measure the line or phase RMS voltages under normal conditions
or under disturbances. This information is internally
processed by the microprocessor, to take the voltage
protection actions defined under ANSI or IEC standards.
Additionally the operational conditions of the breaker or
disconnector are also signalized. The different functions
provided by the VMPR may be classified into the following
groups:
Applications:
- Protection of generators,
motors and transformers against adverse system voltage
conditions.
- Supervision of automatic
transfer switching schemes.
Protection:
- Selection of protection curves
a definite time.
- Two (2) inputs monofase or
trifase of voltage (VT1 and VT2).
- Timed and instantaneous
Undervoltage (ANSI 27t/27i).
- Residual Undervoltage (ANSI
27r).
- Timed and instantaneous
Overvoltage (ANSI 59t/59i).
- Homopolar Overvoltage (ANSI
59N).
- Voltage unbalance (ANSI 46).
- Overfrequency and
Underfrequency (ANSI 81).
- Phase reversal (ANSI 47).
- Five (5) output relay
programmable.
- Loss of control volts relay.
- 4 contact inputs from external
devices (breaker # 1 status, breaker #2 status, external
reset and input 1).
Digital
Measurement:
- RMS line or phase voltages.
- Line or phase voltage
unbalance.
- Average voltage.
- Supply frequency.
- Phase sequence.
Signaling and
Programming:
- LED and LCD display
indication.
- Touchpad programming.
- Indication and storage of
fault conditions and their values.
- Indication of the breaker or
disconnector position (open or close).
Communication:
- Remote digital communication
to a PC or PLC, via RS422 or RS485.
- Remote adjustment of
protection and relay characteristics.
- Storage of faults and events
for further statistical treatment.
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