Basler Electric BE159N – Multifunction Solid‑State Protective Relay

The Basler Electric BE159N (model BE159N-0, style A7ED1JC0S0F) is a compact solid‑state relay that integrates overvoltage (ANSI 59), undervoltage (27), and frequency (81) protection in a single unit. It is designed to protect generators, motors, and feeders from abnormal voltage and frequency conditions that could cause equipment damage or system instability.

Protection Elements

The relay monitors three‑phase voltage inputs and provides independent settings for each element. The overvoltage element trips when any phase voltage exceeds the set threshold, while the undervoltage element trips when voltage falls below a minimum level. The frequency element detects both overfrequency and underfrequency conditions, with separate pickup and time delay settings. All elements are adjustable via front‑panel controls, and the relay includes a seal‑in target for trip indication.

• Voltage inputs: 120/240 V AC, 50/60 Hz

• Overvoltage pickup: 100–130% of nominal, adjustable

• Undervoltage pickup: 70–95% of nominal, adjustable

• Frequency pickup: 45–65 Hz, adjustable

• Time delays: 0.1–10 seconds per element

• Accuracy: ±2% for voltage, ±0.05 Hz for frequency

• 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, alarm, and trip per element

• Mounting: panel draw‑out case

• Operating temperature: –20 °C to +65 °C

Application Areas

This relay is widely used in generator protection panels, motor control centres, and transformer feeders. It provides backup protection for over‑excitation, loss‑of‑field, and system frequency deviations. Its compact size and multiple functions reduce panel space and simplify wiring.

Installation and Configuration

Mounting is via a standard panel cutout with all settings accessible on the front face. Each element has its own potentiometer and DIP switches for pickup and time delay. A test jack allows verification without live power.

Reliability and Standards

Built with Basler's proven analog and digital hybrid technology, the BE159N offers high surge immunity and thermal stability. It complies with IEEE C37.90 and IEC 60255 standards, ensuring reliable protection in industrial and utility environments.

In summary, the Basler Electric BE159N provides comprehensive voltage and frequency protection in a single, reliable package, essential for safeguarding critical power equipment.