Basler Electric BE1-67N – Directional Overcurrent Relay for Ground and Phase Protection

The Basler Electric BE1-67N is a solid‑state directional overcurrent relay that combines overcurrent sensing with directionality to provide selective protection for radial and looped power systems. It is particularly effective for detecting ground faults and phase‑to‑phase faults in generator, transformer, and feeder circuits.

Operating Characteristics

This relay measures both current magnitude and phase angle relative to a polarising voltage or current. The directional element ensures that tripping occurs only when fault current flows in the forward direction, preventing unnecessary operations for reverse faults. The overcurrent unit offers a wide range of pickup settings and time‑current characteristics, including inverse‑time, definite‑time, and very‑inverse curves.

• Current pickup: 0.5–20 A (phase) and 0.1–4 A (ground)

• Time dial: 0–10 (adjustable in 0.1 steps)

• Directional sensitivity: ±2° accuracy at rated voltage

• Output: two Form‑C contacts, 5 A at 250 V AC

• Power supply: 120/240 V AC or 125/250 V DC

• Temperature range: –20 °C to +65 °C

Application Scenarios

The BE1-67N is commonly deployed as the main protection for medium‑voltage feeders, generator step‑up transformers, and capacitor banks. Its directional supervision prevents false tripping on downstream faults, while the ground‑fault element provides high‑sensitivity detection for arcing or high‑impedance faults. The relay is compatible with both solidly grounded and resistance‑grounded systems.

Installation and Testing

Housed in a standard draw‑out case, the relay allows quick insertion and removal without de‑energising wiring. Front‑panel test points and switches enable functional testing and simulation of fault conditions. The BE1-67N includes a target indicator that latches on trip, aiding fault analysis.

Proven Reliability

Basler Electric’s BE1 series is known for its robust analog circuit design and high surge withstand capability. The BE1-67N meets or exceeds ANSI/IEEE C37.90 requirements, offering dependable operation in substation environments. Its long service life and minimal maintenance make it a cost‑effective protection solution.

In summary, the Basler Electric BE1-67N directional overcurrent relay delivers precise, selective fault protection for critical power system assets.