Basler BE3-25-1D1N4 9319100106 480V Relay
The Basler BE3-25-1D1N4, identified by part number 9319100106, is a solid‑state overcurrent relay designed for protection of industrial power systems at 480 VAC. This relay is part of the BE3 family, known for high accuracy, fast response, and reliable performance in motor, transformer, and feeder protection applications.
Relay Function and Principle
The BE3-25-1D1N4 continuously monitors the line current through an external current transformer. When the measured current exceeds a preset pickup level for a specified time delay, the relay activates its output contacts to trip a circuit breaker or initiate an alarm. The relay employs true RMS sensing to ensure accurate measurement even with distorted current waveforms, making it suitable for modern non‑linear loads.
Key Features
Adjustable pickup current: 1–10 A AC (secondary) via internal DIP switches.
Definite time delay: 0.1–60 seconds, field‑adjustable.
Inverse time characteristic options (selectable).
High accuracy: ±2 % of setting over the full temperature range.
Wide auxiliary supply: 24–250 VDC or 120/240 VAC.
Two independent output relays (SPDT) rated 5 A at 250 VAC.
Front‑panel LED for trip indication and power status.
Compact draw‑out case for easy replacement.
Technical Specifications
The relay operates at a nominal system voltage of 480 VAC (line‑to‑line) with a frequency of 50/60 Hz. The current input range is 1–10 A from a standard 5 A CT secondary. The relay burden is less than 0.5 VA per phase. The pickup accuracy is ±2 % of the set value, and the repeatability is ±1 %. The operating temperature range is -20 °C to +60 °C, with a humidity tolerance of 95 % non‑condensing. The insulation voltage is 2500 VAC for 1 minute between input and output.
Setting and Configuration
Configuration is performed using the front‑panel knobs and DIP switches. The pickup current is set by selecting the appropriate tap on the internal transformer and fine‑tuning with a potentiometer. The time delay is adjustable via a separate potentiometer, with a range from 0.1 to 60 seconds. The relay also offers an inverse‑time characteristic that can be enabled for better coordination with downstream devices. A manual reset button is provided on the front panel.
Installation and Wiring
Mount the relay in a standard 19‑inch rack or panel cutout. Connect the CT leads to the designated input terminals, observing polarity. The auxiliary supply must be connected to the appropriate terminals; polarity must be observed for DC supplies. The output contacts are wired to the trip coil of the circuit breaker or to an alarm circuit. Ensure all wiring is properly shielded and segregated from power cables to avoid noise interference.
Applications
The BE3-25-1D1N4 is commonly used for overcurrent protection of motors, transformers, distribution feeders, and generators. It is suitable for both industrial and utility environments, providing reliable protection against overloads and short circuits. The relay can also be used as a backup protection device in conjunction with differential or distance relays.
Testing and Commissioning
Before commissioning, perform a secondary injection test to verify the pickup current and timing. Inject a known AC current into the CT input and gradually increase it to the pickup point. Measure the time delay with a stopwatch. Adjust the settings if necessary. Also check the continuity of the output contacts and the auxiliary supply voltage.
Maintenance
Routine maintenance includes visual inspection for dust, corrosion, and loose connections. Test the relay annually using a secondary injection test set. Re‑calibrate the pickup and timing if the system configuration changes. The solid‑state design ensures long service life with minimal maintenance.
Comparison with Electromechanical Relays
Compared to electromechanical overcurrent relays, the BE3-25-1D1N4 offers higher accuracy, faster response, and better repeatability. Its true RMS sensing eliminates errors caused by harmonic distortion, and the solid‑state construction provides greater resistance to vibration and shock. The adjustable inverse‑time characteristic allows better coordination with other protective devices.
Compliance
This relay is designed to meet ANSI/IEEE C37.90 and IEC 60255 standards. It is UL listed and CSA certified. The unit also complies with RoHS and REACH directives.
Conclusion
The Basler BE3-25-1D1N4 9319100106 480V relay is a versatile and reliable overcurrent protection device. Its robust design, flexible settings, and high accuracy make it a preferred choice for industrial power system protection.
