RELIANCE 803456-3T

803456-3T is an original field excitation thyristor rectifier power module designed for RELIANCE FlexPak3000 series DC variable speed drives, upgraded based on the basic version 803456-3. The suffix T represents thermal optimized version with improved heat dissipation structure. Equipped with enclosed metal housing and single-phase phase-controlled rectifier circuit, this module provides adjustable stabilized DC excitation power for DC motor field winding. It is a discontinued OEM spare part and extensively applied for replacement maintenance and equipment renovation of aging DC speed regulating devices on conventional industrial production lines.

803 stands for fixed platform code of FlexPak3000 plug-in power module product family.456 is exclusive circuit coding for single-phase field excitation rectifier integrated with closed-loop constant current limiting control circuit.3 means the third formal hardware revision with optimized internal surge suppression and power circuit layout compared with earlier editions.T denotes thermal enhanced version with upgraded heat sink structure to improve heat dissipation performance under continuous loaded operation.

Single-phase AC input voltage ranges from 115VAC to 460VAC and fits 50Hz and 60Hz industrial power supply worldwide. Adjustable DC output voltage is within 44VDC to 47.5VDC, and the maximum continuous rated output current reaches 12.8ADC while normal operating current is between 5ADC and 6.5ADC. Continuous operating ambient temperature ranges from -20℃ to +55℃, and transient peak withstand temperature is limited to 70℃. The applicable relative working humidity is 5% to 92% under non-condensing environment. Built-in input fuse, overcurrent protection, short-circuit protection and field open-circuit rapid cutoff circuit are configured. The overall dimension is approximately 290mm×171mm×68mm and net weight is around 4.78kg with integrated heat sink assembly.

Heavy-duty screw type high-current power terminals are reserved for external AC power input connection and DC output wiring leading to motor excitation winding. A set of pin signal terminals connects to drive main control board via internal wiring harness for receiving field current adjustment analog command and returning fault interlock feedback signal. No standard fieldbus communication interfaces such as Modbus, Profibus or DeviceNet are arranged on the module, and only hardwired analog signal interaction is available without digital network data transmission capability.

The module converts input single-phase alternating current into adjustable stable direct current through thyristor phase-shift rectification to sustain steady magnetic field for DC motor field winding during full-range variable speed operation. The built-in closed-loop current regulating circuit automatically adjusts output voltage to compensate current fluctuation resulting from power grid voltage variation and winding temperature rise. The optimized heat dissipation design of T version effectively lowers internal component temperature rise under long-time continuous load running. Once overcurrent, output short-circuit, field winding open-circuit or internal overheat is detected, internal protection circuit immediately cuts off DC output and transmits fault signal to main control unit to lock drive operation and protect motor excitation coil from burnout. An onboard adjustable potentiometer allows on-site fine calibration of output excitation voltage to match different motor rated parameters.

This power module is fully compatible with all non-regenerative and four-quadrant types of RELIANCE FlexPak3000 DC speed controllers. It is installed inside closed electrical control cabinets of papermaking winding and unwinding equipment, ordinary metal wire drawing machine, general plastic extruder spindle and auxiliary metallurgical rolling transmission DC drive systems. It is applicable for regular indoor working environment without severe dust, corrosive gas or intensive mechanical vibration and serves as standard replacement spare for routine equipment maintenance and old production line upgrading projects.

Cut off the complete main AC input power of matched DC drive and wait no less than 15 minutes for full residual electricity discharge of internal capacitors before disassembly or replacement to avoid electric shock and internal component damage. Fully tighten all power terminal screws after installation to prevent poor contact caused by long-term equipment vibration. During periodic maintenance, clear accumulated dust on casing and heat sink with low-pressure dry compressed air and prohibit high-speed airflow directly impacting thyristor and precision small electronic components. Replace the whole module directly in case of continuous output voltage drift, frequent input fuse burnout or irreversible internal circuit damage, and on-site discrete component repair is not recommended. Store unused spare modules in sealed constant-temperature dry warehouse away from corrosive gas and violent mechanical collision.