Basler BE1-87G Generator Differential Relay P/N 9170818100
The Basler BE1-87G, part number 9170818100, is a high‑performance generator differential relay that provides rapid and selective protection against stator winding faults. This specific variant is factory‑configured with a standard setting range and is widely used in medium‑to‑large generator installations worldwide.
Relay Functionality
Like the standard BE1-87G, this relay operates on the high‑impedance differential principle. It compares the currents entering and leaving the generator stator winding. Any internal fault creates a differential current that generates a voltage across the relay’s operating coil, causing it to trip. The high‑impedance design ensures that external fault currents do not cause maloperation.
Distinctive Features of P/N 9170818100
Pre‑calibrated pickup settings for common generator sizes.
Enhanced surge withstand capability for harsh electrical environments.
Wide auxiliary supply range (24–250 VDC) for versatile installation.
Front‑accessible test points for easy field verification.
Compact, draw‑out case with clear terminal identification.
Technical Data
This relay has a nominal pickup current range of 0.5–10 A AC, adjustable via internal jumper settings. The frequency response covers 50/60 Hz with minimal error. Operating time is less than 2 cycles at pickup current. The relay consumes less than 5 VA from the DC auxiliary supply. The stabilising resistor is included and rated for continuous power dissipation up to 50 W.
Application Scope
Ideal for generator protection in utility power stations, industrial cogeneration, and renewable energy plants. The relay can be used with any CT ratio and is suitable for both grounded and ungrounded generator systems. Its high sensitivity allows detection of low‑level faults that may escalate into catastrophic failures.
Installation Instructions
Mount the relay in a dry, dust‑free location with adequate ventilation. Connect the CT leads to the designated terminals, observing polarity markings. The stabilising resistor must be connected as per the wiring diagram. Use copper conductors of appropriate gauge for the CT secondary circuits to avoid excessive burden.
Calibration and Testing
Before energising the relay, verify the DC supply voltage and polarity. Perform a secondary injection test using a three‑phase current test set. Inject balanced currents and confirm no trip; then introduce a differential current and measure the trip threshold. Adjust the pickup setting if necessary using the internal DIP switches.
Operational Considerations
The relay includes a memory circuit that retains the trip indication until manually reset. This feature aids in fault diagnosis. The trip output is a heavy‑duty contact rated for 250 VAC/DC at 5 A, suitable for direct tripping of circuit breakers or connection to a control system.
Maintenance Schedule
Inspect the relay annually for visual damage and tightness of terminal connections. Clean the front panel and test jack. Re‑test the pickup and timing every five years or after any major system change. Keep a record of settings for future reference.
Reliability and Standards
This product is manufactured under ISO 9001 certification and complies with IEC 60255 and ANSI/IEEE standards for protective relays. It has undergone type tests for temperature, humidity, vibration, and electrical transients to ensure long service life.
Conclusion
The Basler BE1-87G P/N 9170818100 offers the same trusted protection as the standard model with the convenience of pre‑set parameters. Its robust design and proven performance make it a reliable choice for safeguarding critical generator assets.
