RELIANCE ELECTRIC S-D4008 – High-Performance Digital AC Drive for Industrial Motor Control

Description

Application Scenarios

At a Midwest food processing plant, a critical ingredient dosing conveyor driven by a ¾ HP motor suffered frequent belt slippage and inconsistent feed rates due to mechanical clutch wear and fixed-speed operation. Replacing the old starter with the RELIANCE ELECTRIC S-D4008 enabled smooth ramp-up/down profiles and precise speed matching to upstream mixers via 4–20 mA feedback. The drive’s sensorless vector control maintained constant torque even at 5 Hz—eliminating product clumping and reducing ingredient waste by 12%. Within six months, the ROI was achieved through material savings alone. In this real-world setting, the S-D4008 didn’t just control a motor—it optimized an entire production parameter.

Technical Principles and Innovative Values

Innovation Point 1: True Sensorless Vector Performance at Low Speed – Unlike basic V/f drives that lose torque below 10 Hz, the S-D4008 estimates rotor flux in real time, delivering up to 150% starting torque at 0.5 Hz—ideal for high-inertia loads like extruders or mixers without encoder cost.

Innovation Point 2: Integrated Braking Transistor – Eliminates the need for external modules in applications requiring fast deceleration (e.g., packaging lines), reducing system footprint and wiring complexity.

Innovation Point 3: Adaptive Auto-Tuning – During initial run, the drive characterizes motor parameters (Rs, Ls, inertia) and stores them, enabling optimal performance even with motor replacements or temperature drift.

Innovation Point 4: Embedded Process Control – Onboard PID loop allows direct pressure, flow, or level regulation using feedback signals—turning the S-D4008 into a standalone process controller without PLC dependency.

Application Cases and Industry Value

A municipal water treatment facility upgraded its chemical dosing pumps from throttling valves to RELIANCE ELECTRIC S-D4008-driven systems. By modulating pump speed based on real-time flow meter feedback via the built-in PID, they reduced energy consumption by 38% and extended diaphragm pump life by minimizing pressure spikes. Meanwhile, a textile mill used the S-D4008’s precise low-speed control to maintain consistent yarn tension during winding—a previously manual adjustment task. Operators reported 90% fewer thread breaks, boosting throughput without additional labor. Across both cases, the drive’s robust design with conformal-coated PCBs (optional) ensured reliable operation in humid, chemically aggressive environments.

Related Product Combination Solutions

Enhance system integration and scalability by pairing the S-D4008 with these complementary Reliance Electric and Rockwell Automation products:

S-D4015: 1.5 HP version for higher-torque applications in the same SP500 platform.

BRAKE RESISTOR (e.g., BRK-50W10R): External dynamic braking resistor for rapid deceleration.

HIM-C6: Hand-held programming keypad for commissioning and troubleshooting.

PowerFlex 4M: Modern Rockwell successor with enhanced communications and safety features.

1746-IB16: SLC 500 digital input module for PLC-based start/stop and fault monitoring.

20-COMM-R: Remote keypad mount kit for panel-door installation.

Line Reactor (e.g., RL-0.75HP-240V): Reduces harmonic distortion and protects against voltage spikes.

RSLogix 500: Legacy programming environment for integrated drive-PLC logic (via Modbus).

Installation, Maintenance, and Full-Cycle Support

Installing the RELIANCE ELECTRIC S-D4008 requires proper grounding, shielded motor cables (≤50 ft recommended), and adequate ventilation (minimum 4″ clearance on all sides). Parameter setup is intuitive via the built-in LED display or optional HIM-C6 keypad, with auto-setup routines for common applications like pumps or conveyors.

For maintenance, the drive logs fault history (overvoltage, overcurrent, overload) with timestamps, aiding root-cause analysis. Capacitors are rated for 10-year life at 40°C, and no routine calibration is needed. Our support team provides application tuning guidance, harmonic mitigation strategies, and migration paths to PowerFlex platforms. Every S-D4008 we supply undergoes full functional test—including motor simulation, braking verification, and communication handshake—and includes a 12-month warranty. Though discontinued by Rockwell, we maintain strategic inventory of tested, surplus units to support legacy installations worldwide.

Contact us for a customized solution—where legacy reliability meets precision motion control, keeping your essential processes running efficiently for years to come.