SIL-G Generator Protection Relays

SIL-G Generator Protection Relays

The SIL-G is a relay for the protection of generators which is able to protect a generator by means of current, voltage and frequency functions. It is normally used with a circuit breaker as cutting element.


  • Protection functions available in SIL-G are the following:
    • 81R, 78, 81 U/O, 27P, 32/40, 59P, 59N, 25, 79, 50P, 50N/G, 67P, 67N, 46, 79, 50BF, 52, 49, 86,CLP, 49T, 74TCS, 37 and IRIG-B.
  • SIL-G monitors differences in voltage magnitudes, phase angles, and frequencies to perform synchronism checks across the circuit breaker. This function can be coordinated with the auto-reclose function (up to five recloses).
  • SIL-G is used with auxiliary power supply (110-230 Vac/ 90-300 Vdc and optionally 24-48 Vdc).
  • Two rear ports on the back for remote communication. Two communication protocols can be used simultaneously:
    • IEC 60870-5-103, IEC 61850, DNP 3.0 or IEC 60870-5-104
  • SIL-G has metallic box with high electromagnetic compatibility level (EMC) and wide range of operating temperature.
  • Direct signalling/control both of the circuit breaker (52 function), both of the recloser (79 function).
  • Its reduced size makes the SIL-G relay easy to install and its light weight helps the customer to save costs in transport.
  • 8 configurable inputs and 7 configurable outputs.
  • 2 Oscillographic records,  20 fault reports and non-volatile RAM memory: stores 1.000 events with date/time even without power supply thanks to its internal RTC.

It is the best solution for Cogeneration, it is normaly used in power stations from gas, steam, hydraulic turbine, or diesel driven generators.