|
DESCRIPTION
The Voltage
Protection Relay (VPR-A) 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. The different functions provided
by the VPR-A 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.
- 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.
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.
- Undervoltage/overvoltage/unbalance/frequency
pickup indicators for calibration testing.
|
