APFC Relays

L&T offers you a wide range of Power factor Correction Relays suitable for all standard applications. Their intelligent adjustment interface ensures balanced usage of capacitors based on the number of switching operations and the connection time of each step, thus ensuring long life for switchgear and capacitors.

    etaCON L Series:

  • Available steps: 3, 5, 7, 8, 12
  • Compact size (96 × 96 mm) in 3, 5, 7 steps version
  • Automatic recognition of current flow direction
  • Auto / Manual Control
  • Online display of PF, Voltage, Current, kVAr, capacitor overload and Panel temperature
  • Average weekly power factor measurement
  • Capacitor over-current and panel over-heating protection
  • No-voltage release protection function
  • Last two can be programmed for Capacitor switching / Alarm / Fan Control
  • Keypad locking function


PGR 8800 provides effective arc flash protection using optical point and fiber sensors. The system generates a trip within 1 millisecond of arc detection. Thus, power may be disconnected within 40-50 milliseconds before it can cause significant damage.


  • Combination of optical point and fiber sensors
  • Redundant internal trip path
  • Continuous health monitoring of sensors
  • Optional current based protection to avoid nuisance tripping
  • Plug –n-play configuration software
  • Easy to retrofit in LV, MV switchboards
  • Provision of back up battery

Discrete Protection Relays

    T4500: Auto synchronizer

  • Automatic synchronization with relay outputs for speed control
  • Adjustable delta frequency and delta voltage
  • Adjustable breaker make time
  • Visual indication of bus voltage, generator voltage, closing signal, delta voltage, increase and decrease signals
  • Automatic voltage matching
  • Operating temperature range: -20°C to +70°C
  • Vibration test up to 4g (5 - 100Hz)
  • Certified by major classification societies
  • Flame retardant enclosure
  • DIN rail or screw mounting

MC12A - 1 Ph O/C + E/F relay

1 phase, non-directional, Over Current or Earth Fault Relay

The relay can be used for feeder protection in all low voltage, medium voltage sub-stations. The relay has a built in high set facility. DIP switches are provided on the front panel for pick up and time delay settings


  • Dual CT Rating
  • Draw out type construction
  • Micro controller based design
  • 7 types of trip time characteristics available

nX Series

nX Series offer you numerical type 3 phase overcurrent & Earth Fault Relay. Its microcontroller based design offers you to choose from various field selectable IDMT & definite curves.


  • Dual CT rating Relay has a unique provision whereby, it can be made suitable for operation from either 1 Amp CT or 5 Amp CT secondary.
  • Large 35mm graphical LCD Display with bigger font size provides excellent viewing for various lighting conditions.
  • Recording of last 15 trip events separately for O/C & E/F with Date and Time stamping
  • Wide range of TMS
  • Universal Auxiliary Supply : 24 to 240 V AC/DC
  • Password Protection

MD32 G Generator Differential and REF

MD32-G is three-phase percentage biased differential protection relay for generators and rotating machines, with stator earth fault or restricted earth fault element.


  • Harmonic Restraint
  • Phase Overcurrent protection
  • Phase Differential protection
  • Dual slope programmable percentage bias curve
  • Earth Fault or Restricted Earth Fault protection
  • Breaker Failure protection
  • Modbus Communication Protocol
  • Maximum Demand and Inrush Recording


MG30 / MG30-I is Multifunction Microprocessor Relay for protection of medium/large synchronous generators. The relay measures the RMS of three-phase currents and voltages and computes the positive and negative sequence components of the Current system.


  • Voltage-controlled overcurrent protection
  • Thermal image element with prealarm level
  • Reverse power protection
  • Loss of Field protection
  • PT s' fuse failure protection
  • Modbus Communication Protocol
  • Breaker Failure protection
  • Inadvertent C/B closure protection
  • Blocking Output and Blocking Input for pilot wire selectivity coordination

MRP11 Reverse Power Relay

MRP11 is micro controller based single phase, reverse power relay with one measuring element. Relay operates for pure active reverse power only and will not cause spurious tripping due to PF fluctuations in the system. Relay can work as a reverse reactive power relay with an addition potential transformer.


  • 0.5% sensitivity
  • Four Quadrant operations
  • Reactive power option
  • Voltage Input: 110 / 415 V AC (Field Selectable)/li>


The relay can be used protection of generators from reverse power conditions or in grid islanding systems for detecting mains failure or prevention of power flow from small generators to grid.

SC14S Instantaneous Earth Fault Relay

SC14S is a self-powered, single-phase, non-directional, Earth fault relay with one measuring element.


  • Micro-controller based design
  • Draw out facility
  • Built in Third Harmonic Filter. It helps to avoid spurious tripping in harmonic rich power systems
  • Instantaneous time delay or delay of 100 ms, 200 ms can be set


MM10 Relay is a microprocessor based Motor Protection Relay with 4 digits LED Display


  • 4 Digit LED display
  • Measurement of RYB, Zero Sequence current and Thermal capacity.
  • Separate LED’s for indication of Motor operational, Trip & Thermal OL/ pre-alarm status.
  • Programmable thermal OL time constant right from 1 sec to 40 sec.
  • 2 nos. of C/O output contacts.
  • Relay testing facility
  • Trip data recording Fault current or cause of last trip is displayed.

MM30 Comprehensive Motor Protection

MM30 is a Microprocessor based Comprehensive Motor Protection Relay designed for Medium and Large Motors


  • Auto setting of parameters
  • Draw out enclosure
  • 8 digit alpha numeric display
  • Real Time Measurements
  • Measurement and display of actual & trip data recordings.
  • 8 LED’s for fault indication.
  • Control on number of starts of motor
  • Starting sequence control. During start-up of the motor, the unit can control an output contact to automatically manage the starting transition.
  • RS485 port for communication with Modbus Protocol.

MPR300 Mini Motor Protection Relay

MPR300 is a Microprocessor based LT Motor protection relay. The relay has got inbuilt CTs for motor sizes up to 50KW (i.e 88 A current)


  • LED’s for trip indication.
  • Inbuilt CTs available
  • 4 selectable trip time curves for thermal overload
  • Test facility through front push button.
  • Manual reset facility through front push button.
  • With / Without fail safe mode