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Phone：+86 17062388866Description
The RELIANCE 57C552-1 is a DC drive controller from Reliance Electric’s FlexPak® 3000 series, engineered for precision speed and torque control in industrial DC motor applications. Designed for demanding environments like steel rolling mills, paper machines, and mining conveyors, this drive delivers robust performance with ±0.1% speed regulation accuracy. The 57C552-1 features advanced thyristor-based power conversion, supporting motors up to 700 HP (522 kW) with full regenerative braking capability. Its modular design simplifies maintenance, while integrated diagnostics monitor motor health, armature voltage, and field current. Compatible with Reliance’s RPM AC/DC motors, this drive ensures seamless integration into legacy automation systems, providing reliable variable-speed control for critical processes.
RELIANCE 57C552-1
Technical Specifications
| Parameter Name | Parameter Value |
| Product Model | 57C552-1 |
| Manufacturer | Reliance Electric (Rockwell Automation) |
| Product Type | DC Drive Controller |
| Output Power | Up to 700 HP (522 kW) |
| Input Voltage | 480V AC ±10% (3-Phase) |
| Output Voltage | 0–500V DC Adjustable |
| Max. Armature Current | 1200A Continuous |
| Field Supply | 300V DC @ 15A |
| Control Accuracy | ±0.1% Speed Regulation |
| Feedback Options | Armature Voltage, Tachometer, Encoder |
| Communication | Optional DPI/SCANport for PLC Integration |
| Protections | Overcurrent, Overtemp, Loss of Field |
| Operating Temperature | 0°C to 40°C (Derate above 40°C) |
| Enclosure | NEMA 1 (IP20) |
| Certifications | UL, CE, cUL |
Main Features and Advantages
Precision control: Dual-loop feedback (armature voltage + tachometer) maintains motor speed within ±0.1% under load variations. The 57C552-1’s CEMF regulation ensures smooth torque during acceleration/deceleration, critical for tension-sensitive applications like web handling.
Diagnostic intelligence: LED status indicators and fault code logging simplify troubleshooting. Built-in I²t thermal modeling protects motors from overloads, while field weakening control extends speed range up to 2:1.
Retrofit-ready: Direct compatibility with Reliance RPM motors reduces commissioning time. Hot-swappable control cards minimize downtime during maintenance.
Application Field
The RELIANCE 57C552-1 excels in heavy-industry applications:
Steel Mills: Controls roll stands and coilers in hot/cold strip lines.
Paper Production: Manages sectional drives in dryer sections with precise speed synchronization.
Mining: Governs hoist and conveyor motors with regenerative braking for downhill loads.
Cement: Regulates kiln drive torque during startup/shutdown sequences.
Related Products
57C494: 400HP FlexPak 3000 drive (compatible control architecture).
57C415-1: Field control module for 57C552-1.
RPM AC DC Motors: Matched motors (e.g., RPMAC3445).
PV300 HIM: Hand-held programmer for drive configuration.
PowerFlex 755: Modern AC drive alternative for retrofits.
