Voltage Frequency Protection Relay
VPR-A
Voltage Frequency Protection Relay
The voltage protection relay VPR-A has been designed to measure the line or phase RMS voltage, frequency and unbalance 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 groups mentioned below.
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Applications
- Protection of generators, motors and transformer against adverse system voltage conditions
- Ground fault detection 59N
- Supervision of automatic transfer switching schemes
Digital Measurement
- RMS line and phase voltages
- Homopolar voltage
- Voltage unbalance
- Average voltage
- System frequency
- Phase sequence
Signalling
- LED and LCD display indication
- Touchpad programming
- Indication and storage of fault condition and their values
- Undervoltage, overvoltage, unbalance, frequency pickup indications
- System status
- Output relays status
Protection and Functionality
- (27t/27i) Timed and instantaneous undervoltage
- (27r) Residual undervoltage
- (46) Voltage unbalance
- (47) Phase reversal
- (59t/59i) Timed and instantaneous overvoltage
- (59N) Homopolar voltage
- (81) Underfrequency and Overfrequency
- Five programmable relay output contacts
- Control power drop or internal fault relay
Communication
- Remote communication using a PC or PLC by 1 RS232 or 2 RS485
- Remote programming of the setpoints
- Remote breaker opening or closing