Product Details

The RELIANCE 5280601, also known as 0-52806-1, is a discontinued tach loss and overspeed protection circuit board for Reliance Electric legacy analog DC drive systems, widely used in metallurgy, papermaking, rolling mill and other heavy-duty continuous production lines. It independently monitors the tachometer feedback signal from the motor shaft, works with the regulator control board to realize overspeed trip and tachometer loss fault protection, preventing motor runaway caused by speed feedback failure.

This board adopts analog comparison and fault latch circuit design. It continuously receives voltage pulse signal from the tachometer generator, calculates actual motor speed and compares it with preset overspeed threshold. Once the speed exceeds the set limit or the tachometer signal is lost, it immediately latches the fault state and outputs hard interlock signal to shut down the drive. Two red LED indicators on the front panel separately display overspeed alarm and tach loss alarm, with manual reset button for fault clearing. It integrates signal filtering and surge suppression circuits to filter tachometer line noise and avoid false triggering from SCR commutation interference. It is a dedicated safety protection accessory for Reliance analog DC drive platform, cannot be directly replaced by other boards without tachometer voltage range matching, overspeed threshold calibration and interlock contact test. Multiple protection boards can be deployed for independent overspeed monitoring of multi-motor drive units.

It adopts rack plug-in installation structure with gold-plated edge connector and front terminal blocks for tachometer input and fault interlock wiring. The PCB layout adopts low-noise and anti-vibration design, adapting to harsh industrial sites with mechanical vibration and power switching noise. Users need to confirm matched regulator board and tachometer generator specification before replacement. This legacy RELIANCE 5280601 board is mainly used for maintenance and retrofit of old Reliance DC drive systems. Tach signal detection test, overspeed trigger point calibration and interlock shutdown sequence verification are required after installation. A conformal coated version is optional for high humidity and dusty industrial sites. This overspeed protection board is widely used in Reliance legacy DC drive renovation, motor overspeed safety protection and tachometer feedback fault monitoring.

This tach loss overspeed protection board obtains working power from the drive internal auxiliary power supply. The edge connector and terminal block support quick disassembly and replacement for convenient on-site maintenance and inspection. The optimal operating temperature range is 0°C to 55°C, storage temperature ranges from -40°C to +85°C, relative humidity 5% to 85% non-condensing. It complies with industrial shock, vibration and EMC standards and has CE certifications. It supports parameter backup for fast recovery after hardware replacement.

This RELIANCE 5280601 protection board is widely applied in Reliance legacy DC drive control systems. It undertakes tachometer signal monitoring, overspeed judgment and safety interlock output. As a reliable spare part for Reliance legacy drive systems, the 5280601 retains original fault detection and safety interlock performance, helping customers reduce maintenance cost of old industrial automation equipment.