Draw-out Ground Fault Relay


  • Provides safety for miners
  • Protects customer’s equipment underground
  • Maximizes mine production


  • Collects Real-time data
  • Predictable failures
  • Secure Settings


Becker has redefined the mining market by developing a new Ground Fault Relay with innovative state of the art technology. The Becker Mining America new SGF-25 Sensitive Ground Fault Relay is a .025- .5 amp Ground Fault Relay that is capable of very sensitive high accuracy ground current and look-ahead protection.

It has the ability to “look ahead” and determine a configurable ground resistance condition before the motor power circuit is energized. A graphical touch screen display is now provided in the single relay assembly, providing real time data, configuration, data log and a help menu.

The new SGF-25 is used to protect electrical cables and motors from phase to ground faults as well as preventing the electrician from closing the circuit into a fault. When the preset level of the fault current and time delay are exceeded, the relay will initiate a trip action. The new SGF25 system uses a current transformer connected in a zero sequence or a ground return sensing method.


  • The new SGF-25 Relay is used for critical 4160 volt applications where very sensitive
  • high accuracy ground current protection with high degree of nuisance tripping immunity is important.
  • This relay is required to properly protect large horsepower circuits.

Existing Features

  • Very sensitive, high accuracy current measurement (.025 to .500 amps)
  • High degree of nuisance trip immunity
  • Time delay tripping range 0 to 250 milliseconds
  • Look ahead circuit that verifies condition of power circuit before energization (Range: 100K to 10M ohm)
  • Accepts CT test winding
  • Remote 120 VAC test trip
  • Remote 120 VAC reset
  • Failsafe design - Output relay coils are energized during non-fault conditions
  • Requires BMA/SMC high noise rejection CT’s

New Features

  • Touch screen VGA display
  • Draw-out relay with mine duty connectors
  • Ethernet capable for writing to a .CSV file or web part
  • USB flash drive connector to upload data log and download firmware
  • Field replaceable lithium battery and VGA display
  • Password protected configuration


Supply Voltage 120 VAC, 50/60 Hz Ground-Current Sensitivity 25, 50, 75, 100, 125, 150, 200, 300, 400, 500 mA Ground-Current Trip Delay 0, 50, 75, 100, 125, 150, 175, 200,225,250 mSec Cable Resistance Sensitivity 100K, 250K, 500K, 750K, 1Meg ohms 2 Form C Contacts 250 VAC, 10 Amps make, 2000 VA break

Part Numbers

SGF-25 Ground Fault Relay Part No. 500-1800 SGF-25 3” CT Part No. C4310-003 SGF-25 5” CT Part No. C4310-005 SGF-25 HV Coupler Part No. C4310-010