Grounds in the field of a synchronous machine must be immediately detected, since the occurrence of a second ground might short circuit part of the field winding, and the resultant unbalance and vibration may damage the machine.
The DGF relay provides a reliable means for detecting grounds in the DC winding of the generator field. It uses a voltage divider consisting of a resistor and varistor connected across the field winding of the generator. The relay operating coil is connected from the mid-point of the voltage divider to ground. A ground in the generator field winding will cause current to flow through the moving coil of the DGF and operate the relay to trip or sound an alarm, as desired.
Why ABB?
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Long production life, ease of application and reliable protection
- High quality design
- 12 year warranty
- Short lead times
- Consistent on-time delivery
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24/7 customer support