MPR 6/3 DGF

MPR-6/3-DGF Motor Protective Relay

With Directional Ground Fault Function & 3 Thermal Sensors

The MPR-6/3 Motor Protection Relay is a new generation of microprocessor based relay designed to protect three phase induction motors.

The MPR-6/3 incorporates two main functions.

• Motor protection.
• Supervision and communication.

A comprehensive protection device is required to accurately create a Thermal Model for the motor to run safely up to its limits. This relay should protect the motor from abnormal conditions in the power supply, motor and cable faults as well as operator malfunctions.

The MPR-6/3 monitors three phase currents (true RMS line currents are measured at a sampling rate of 0.5 mSec). The MPR-6/3 monitors ground fault current (true RMS) and zero sequence voltage (3Vo), for Directional Ground Fault protection. The MPR-6/3 monitors three temperature (RTD or PTC/NTC Thermistor) inputs. Finally, the MPR-6/3 provides a comprehensive protection package.

Protection

• Too many starts
• Maximum start time
• Undercurrent
• Load Increase
• Thermal level (Overload) - Two Levels
• Over-current Jam / Stall & Short circuit - Two Levels
• Unbalanced current - Two Levels
• Directional Ground fault current
• Phase Sequence
• Temperature (3 Sensors)- RTD Pt.100 or 3 PTC/NTC Thermistor - Two Levels
• External fault 1- N.O/N.C contacts
• External fault 2 - N.O/N.C contacts

Inputs

• 3, 5A Phase C.T.'s (1A is also available)
• 2, Programmable Discrete inputs
• 1, Residual Ground Current Input
• 1, Open Delta Voltage Input
• Control Voltage Supply (115,230VAC 50/60Hz,110VDC)
• 3, RTD/Thermistors

Outputs

• 1, Alarm Relay fail safe (8A/250V)
• 1, Trip Relay trip/trip-fail safe (8A/250V
• 2, Programmable (8A/250V)
• 1, Programmable Analog Output

Display - LCD

• 2, Lines Illuminated LCD
• 4, LED's

Communication

RS485 Serial Link With Modbus / Profibus Protocol at baud rate of 1200 to 9600 bit/sec.

Actual Data

• I 1, I 2, I 3 Phase Currents
• T 1, T 2, T 3 RTD's Temperatures
• % of Motor FLC
• Unbalance Current
• I 0 Residual Current, 3V 0 Zero Sequence Voltage
• Thermal Capacity
• Time to Trip
• Time to Start

Statistical data

• Total run time
• Total number of starts
• Total number of trips
• Last start time period
• Last Start Max. Current
• Trip I 1 , I 2 , I 3
• Trip I 0 , 3V 0
• Trip T 1 , T 2 , T 3
• Last Alarm Thermal Level 1
• Last Trip Thermal Level 2