Basler Electric BE1‑60 Solid State Protective Relay

The Basler Electric BE1‑60 is a solid‑state voltage balance relay that protects three‑phase motors, generators, and transformers from the damaging effects of voltage unbalance. Unbalanced voltages produce negative‑sequence currents that cause rotor heating, excessive vibration, and premature insulation failure. The relay monitors the ratio of negative‑sequence to positive‑sequence voltage (V2/V1) and trips when the imbalance exceeds a preset level for a selected time delay. Its precise measurement and adjustable settings ensure reliable protection in industrial and utility applications.

Measurement and Settings

The relay computes the V2/V1 ratio and compares it to an adjustable setpoint, typically from 2% to 15% unbalance. The time delay is adjustable from 1 to 30 seconds, allowing coordination with motor starting and transient conditions. A front‑panel potentiometer sets the pickup level, and a separate dial adjusts the delay. The relay includes a target indicator with manual reset and a test pushbutton for functional verification. An LED indicates the presence of unbalance.

Design and Construction

Housed in a rugged metal enclosure suitable for panel mounting, the BE1‑60 features solid‑state circuitry with high immunity to harmonics and transients. It includes one Form C output contact (rated 5 A at 250 VAC) for tripping or alarming. An integral power supply accepts a wide range of AC or DC voltages, simplifying installation.

Technical Specifications

Input voltage: 100‑480 VAC, 50/60 Hz, three‑phase. Pickup range: 2‑15% unbalance (adjustable). Time delay: 1‑30 seconds. Accuracy: ±2% of setting. Output contacts: 1 Form C, 5 A at 250 VAC. Power supply: 24‑250 VDC or 120‑240 VAC. Burden:<5 VA. Operating temperature: –20°C to +65°C. Meets IEEE C37.90 surge withstand.

Applications

The BE1‑60 is used in motor control centers, generator protection panels, and transformer monitoring. It protects large motors, generators, and sensitive equipment from voltage unbalance caused by unbalanced loads, single‑phasing, or transformer faults. It can also be used to alarm for preventive maintenance.

Installation and Commissioning

Mount the relay in a panel cutout. Connect the three‑phase voltage inputs and control power. Commissioning involves setting the pickup and time delay, then testing with an unbalanced voltage source. The relay includes a test jack for secondary injection. Regular calibration is recommended.

Reliability and Quality

Basler Electric’s BE1‑60 is built with high‑quality components and conformal coating. It is factory calibrated and tested for environmental endurance. The relay offers long service life with minimal maintenance.

Conclusion

The Basler Electric BE1‑60 solid‑state protective relay provides sensitive and reliable protection against voltage unbalance, safeguarding critical rotating equipment from thermal damage and ensuring system reliability.