GFR4000 Ground Fault Monitor
The GFR4000 continuous ground fault monitor relay is specifically designed to provide complete motor protection without the problems associated with high sensitivity nuisance tripping. The GFR 4000 is unique because it has predictive as well as protective capabilities. The unit operates continuously in one of two modes, either on-line or off-line. The GFR4000 has metering output signals for use with a remote meter or PLC so that ground faults may be detected at an early stage.
The GFR4000 operates on grounded, high resistance grounded and ungrounded systems. The unit can be directly connected to supplies up to 1300V, 1PH or 3 PH, 50-60 HZ. For supplies from 1300 V to 5000 V, the GFR 4000 must be connected to the HTC 5000 high tension coupling unit.
On-Line Mode Under normal running conditions the GFR 4000 operates as a sensitive ground fault relay working in conjunction with a separately connected current transformer. The alarm range is adjustable with a 10 position range of fixed operating points between 10 mA and 3A. Time delay is adjustable between 0 and 1 seconds. When the preset response value is exceeded, the GFR4000 operates the output relay after the preset time delay. There is instant LED indication. The unit can be set for Active or Failsafe mode and has memory and auto reset facilities. The GFR 4000 also monitors the loop connection to the current transformer and provides LED indication should it detect a C.T. fault.
Off-Line Mode The GFR4000 automatically changes state by means of a small auxiliary contact on the main contactor when the motor (or load is switched off. The unit becomes a high performance insulation resistance monitor. It imposes a small DC current onto the network which thravesl throught the motor windins and interconnecting cable from the motor starter. A green LED indicates that the off-line moniotoring function is active. The insulation resistance function of the GFR has an adjustable alarm range from 250 kΩ – 2 MΩ. The red LED indicates “low resistance” and operates instantly when the trip relay is activated. The off-line feature also has an Active/Failsafe Mode and Memory/Auto Reset facilities. The metering output is 0-1mA FSD and relates to an insulation range of 0 to infinity.
Datasheet
- GFR4000 - Download PDF (127 KB)