Machine Protection


The GRE170 is a fully numerical multi-function machine protection device designed for medium and small capacity generator and motor protection applications, drawing on proven technologies developed over more than 100 years, and providing a comprehensive range of protection and control functions.

  • • Protecting generator and motor
  • • Basic machine protection and comprehensive backup protection including directional and non-directional overcurrent and earth fault protection, thermal overload and optional current differential protection and RTD input for temperature measurement.
  • • Feeder manager device with CB control function, 43R/L switch and comprehensive supporting functions
  • • Compact and cost-effective design
  • • Elementary, environmentally-friendly, easy to use and enhanced product concepts

GRE170 has three models which differ according to the number of analog inputs and type of neutral current inputs.

The second digit of the model identifies input type for neutral current input. For example of model *0*, normal zero-phase current is input, and model *2* is equipped with a sensitive earth fault current input.

For each model, there are three different types which differ depending on the number of binary inputs and outputs. Combined 1A/5A current inputs and wide auxiliary supply ranges simplify type selection.

All models include multiple, high accuracy generator and motor protection elements such as overcurrent protection elements (for phase and/or earth fault) with inverse time and definite time delay functions, in accordance with the IEC 60255-151 standard, directional overcurrent protection, negative sequence overcurrent protection, voltage protection, motor status monitoring, locked rotor protection, number of starts limitation, start/stalled protection and thermal protection based on IEC 60255-8. Control functions such as two-step operation of circuit breakers are also provided.

Sensitive earth fault protection or current directional protection functions is available according to model type.

Table 1 - GRE170 Models

Model 100 Three phase current input
Model 200 Three phase current and four phase voltage input
Model 300 Model 200 + three phase current input for current differential protection
Model Configuration
GRE170-**0 6 x Bls, 4 x BOs and Fail BO
GRE170-**1 12 x Bls, 10 x BOs and Fail BO
GRE170-**2 18 x Bls, 16 x BOs and Fail BO

All models provide continuous monitoring of internal circuits and of software. External circuits are also monitored, by trip circuit supervision, CT and VT supervision, and CB condition monitoring features.

A user-friendly HMI is provided through a backlit LCD, programmable LEDs, keypad and menu-based operating system. PC access is also provided, either for local connection via a front-mounted USB port. The communication system allows the user to read and modify the relay settings, and to access data gathered by the relayĆ¢s metering and recording functions.

Data available either via the relay HMI or communication ports includes the following functions: metering, fault, event and disturbance recording.

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