Sensitive Earth Fault Relay -Current Protection
Current Protection
Description
Features
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High sensitivity (0.1% of Is)
- 2nd & 3rd harmonic & HF noise suppression
- Tuned to 50 Hz or 60 Hz
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Optional reset functions: Instantaneous (Fast), definite time, count down
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40-300V DC aux. supply
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20-70V DC aux. optional
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Low CT burden & high thermal rating
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Optional 1A or 5A CT input
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Instantaneous pick up LED
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Configurable output contacts
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0-31s time delay (125ms steps)
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Push button / electrical flag reset
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Non-volatile trip indication
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Multi voltage inhibit / enable input
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Multi voltage flag reset input
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Auxiliary supply fail alarm
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Flush or rack mount draw out case
Description
The main earth fault protection relays in distributions systems, power stations & large manufacturing / processing plants can fail to detect a high impedance break down to earth causing hazard to human life & potential damage to plant & equipment. In these & other situations demanding extra sensitive earth fault protection, the 2C138 relay using solid state techniques, can be applied to detect earth currents down to 0.5% of the CT nominal current.
The relay is tuned to reject 2nd & higher harmonic frequencies to avoid problems under quiescent conditions. An adjustable time delay is built in to provide stability during switching & other transient disturbances & to allow adequate grading with other protection systems at high fault current levels.
