ABB SPAD 346 C3 Differential Voltage Relay

The ABB SPAD 346 C3 Differential Voltage Relay protects critical equipment by monitoring the voltage difference between two points. It senses imbalance in three‑phase systems or between bus sections. When the differential voltage exceeds a set threshold, the relay trips within a set time to isolate the faulted section. The adjustable pickup range from 10 V to 100 V allows tuning for different system voltages. Trip times can be set between 20 ms and 200 ms to match coordination requirements. This relay supports manual or automatic reset modes. In manual mode, an operator must clear the fault and press the reset button. In automatic mode, the relay resets once the voltages return to normal. The front panel provides three LEDs: green for normal operation, yellow for trip, and red for fault. These indicators let technicians see the relay’s status at a glance without tools.

The SPAD 346 C3 runs on a wide supply voltage range of 110 to 240 V AC or DC. It draws under 5 W during normal operation. It has built‑in surge protection and meets IEC 61000‑4 standards for immunity to electrostatic discharge and surge events. The relay resists harsh industrial environments with a temperature rating from –20 °C to +55 °C. It also stands up to vibration and shock. The housing is robust and seals to IP40 when mounted on panel. Connections use screw‑clamp terminals rated for 10 A continuous load. The device undergoes routine self‑tests every 100 ms to check internal circuits. If it detects a fault in its power supply or sensing inputs, it disables operations and flashes the red LED. Engineers can use test points on the board edge to quickly measure input voltages without removing the relay from the panel. The front‑panel firmware port allows field upgrades of trip curves and diagnostic logic.

Modern substations and process plants rely on differential relays to protect transformers, busbars, and generator windings. A 2025 power industry report highlights that differential protection installs are growing at over 8 percent per year as utilities upgrade aging grids. Facilities that deploy advanced differential relays report up to 25 percent fewer relay maloperations and faster fault isolation. The SPAD 346 C3 aligns with this trend by offering precise voltage sensing, fast trip times, and built‑in diagnostics. It integrates into SCADA and DCS networks by providing contact outputs for remote trip signals and fault alarms. Zhangzhou Fengyun Electric Equipment Co., Ltd. stocks this relay and other ABB protection products. The company offers full lifecycle support, from system design to on‑site commissioning and after‑sales service. With strong import/export channels and a large inventory of automation modules, Fengyun Electric delivers worldwide. Their technical team assists with integration, testing, and preventive maintenance. For more information visit their official site or explore detailed specs on the product page.

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