Basler Electric BE1-87G – Generator Differential Relay (Style S1A‑A1C‑A0N0)
The Basler Electric BE1-87G (style BE187GS1AA1CA0N0) is a high‑speed percentage differential relay that protects generator stators from internal winding faults. It compares the currents at each end of the stator windings and trips when a fault current is detected.
Protection Principle
The relay measures the differential current and applies a percentage restraint characteristic to remain stable during external faults. The pickup and slope settings are adjustable to accommodate different generator sizes and CT characteristics.
Current inputs: 1 A or 5 A CT secondaries
Pickup setting: 0.1–2.0 A
Slope setting: 10–40%
Operating time: < 30 ms
Output contacts: 2 Form‑C relays, 5 A at 250 V AC
Power supply: 120/240 V AC or 125/250 V DC
LED indicators: power, trip
Mounting: panel draw‑out case
Operating temperature: –20 °C to +65 °C
Applications
This relay is used as primary protection for generators in utility and industrial power plants.
Installation and Settings
Mounting is via standard panel cutout. Front‑panel controls allow adjustment of pickup and slope.
Reliability
Complies with IEEE C37.91 and IEC 60255 standards.
In summary, the Basler Electric BE1‑87G provides fast, selective protection for generator stators.
