Case Study: Upgrading Conveyor Control with Allen Bradley PowerFlex 525
Industrial conveyor systems are the heartbeat of many manufacturing plants, but ageing motor starters can cause unnecessary downtime and energy waste. This case study highlights how a UK-based packaging manufacturer upgraded from outdated star-delta starters to modern Allen Bradley PowerFlex 525 variable frequency drives (VFDs) — achieving smoother operation, 25% faster production changeovers, and a 15% reduction in maintenance costs within the first six months.
We’ll cover the challenges, solution design, integration process, and measurable outcomes, while linking useful resources like our VFD Sizing Calculator and Cable Sizing Calculator to help you replicate similar results in your facility.
Background: Legacy Conveyor System Issues
The customer operated a high-speed packaging line with six conveyor sections, each driven by 5.5 kW three-phase motors. The control system relied on mechanical contactors and star-delta starters installed over 15 years ago. The main issues included:
- ⚙️ Harsh mechanical shock during startup
- ⚙️ Frequent belt stretching and motor bearing failures
- ⚙️ Limited control flexibility — only “ON/OFF” operation
- ⚙️ Increased downtime for maintenance and parameter tuning
Production engineers identified that upgrading to intelligent drives could improve speed synchronisation between conveyors, reduce wear, and provide valuable diagnostics through PLC integration.
Project Goals
- 🔹 Introduce soft starting and controlled acceleration
- 🔹 Enable speed control to match packaging machine throughput
- 🔹 Reduce downtime through built-in diagnostics
- 🔹 Integrate VFDs with the existing PLC and HMI system
Solution: Allen Bradley PowerFlex 525 Drive System
The engineering team selected Allen Bradley PowerFlex 525 drives for their modular design, compact size, and advanced Ethernet/IP communication. Each conveyor motor was paired with an individual drive inside an upgraded stainless-steel MCC panel.
Key Features Used
- ✔️ Embedded Ethernet/IP & Modbus TCP for seamless PLC integration
- ✔️ Sensorless vector control for torque stability
- ✔️ Safe Torque Off (STO) for machine safety compliance
- ✔️ Detachable keypad with copy function for quick configuration
- ✔️ Compact footprint suitable for retrofit projects
Alternative drives such as the PowerFlex 523 were also evaluated, but the PowerFlex 525 offered enhanced connectivity and energy optimisation features ideal for the customer’s Industry 4.0 roadmap.
Design and Drive Sizing
Each conveyor motor’s data was entered into the VFD Sizing Calculator to determine drive ratings with sufficient overload margin for heavy product loading. Drive ratings were standardised at 7.5 kW (10 HP) to provide extra torque during ramp-up.
Motor cable runs were between 15–30 m, verified using the VFD Cable Sizing Calculator to ensure proper conductor cross-section and voltage drop limits. The team also sized braking resistors using the Braking Resistor Calculator for two conveyors handling rapid deceleration zones.
Installation Process
The old starters were removed and replaced with a single enclosure housing six PowerFlex 525 drives. Ethernet/IP network cabling linked the drives to an existing CompactLogix PLC and PanelView Plus HMI.
Setup Highlights
- ✅ Motor auto-tune completed on all six drives
- ✅ Accel/decel ramps set to 5 s and 4 s respectively
- ✅ Forward/reverse logic controlled via PLC outputs
- ✅ Real-time speed feedback displayed on HMI
- ✅ STO safety circuit wired to emergency stop loop
The commissioning phase took just two days — 50% faster than expected thanks to the drives’ parameter copy function and user-friendly keypad interface.
Results and Performance Improvements
| Performance Metric | Before | After PowerFlex 525 Upgrade |
|---|---|---|
| Average Downtime per Month | 10 h | 5 h (−50%) |
| Belt Wear & Replacements | Every 9 months | Every 14 months (↑ 55%) |
| Maintenance Cost | £2,100/month | £1,800/month (−15%) |
| Power Consumption | Baseline | −12% |
Operators now adjust conveyor speed via HMI during product changeovers, reducing downtime between batches by 25%. The drives’ built-in diagnostics simplified fault detection — identifying overloads or supply faults directly on the HMI without manual inspection.
Operator Feedback
“Our conveyors start smoothly, and we’ve stopped seeing belts jump or motors trip. The PowerFlex 525 drives have made speed coordination between sections effortless. It’s one of the best automation upgrades we’ve done.” – Maintenance Supervisor, Packaging Division
Integration with Control System
The drives communicate with the existing Allen Bradley CompactLogix PLC via Ethernet/IP. Each VFD transmits live parameters such as speed, current, torque, and fault codes to the SCADA dashboard. This allows predictive maintenance alerts and remote performance monitoring.
Using PowerFlex 525’s Add-On Profile (AOP) in Studio 5000, the engineering team quickly mapped drive parameters into the PLC logic without custom code, reducing programming time by 40%.
Energy Savings and Process Optimisation
By running conveyors only as fast as required, the plant achieved measurable kWh reduction. The PowerFlex 525’s sleep/wake functions automatically stop conveyors when upstream sensors detect no load, further reducing idle energy waste. Combined with the VFD’s regenerative braking, total energy savings reached approximately 9 MWh in the first half-year of operation.
For further optimisation, the customer plans to install a PowerFlex 755 drive on their main feed conveyor to integrate torque control with the packaging machine’s load cell feedback.
Lessons Learned
- 🔹 Always verify motor FLA and torque curve during VFD selection — use the VFD Sizing Calculator.
- 🔹 Use shielded cables and correct earthing to maintain EMC compliance — reference our Cable Sizing Calculator.
- 🔹 For rapid deceleration, size braking resistors properly with the Braking Resistor Calculator.
- 🔹 Plan drive addressing and naming conventions early for easier PLC integration.
Next Phase: System Expansion
With successful results on the first line, the manufacturer is expanding the upgrade to two additional conveyors using the PowerFlex 523 series for smaller 3 kW motors. These drives share the same programming environment and communication architecture, ensuring easy integration with the existing PowerFlex 525 network.
Financial Summary
- 💰 Project Cost: £18,000 (hardware + integration)
- ⚡ Annual Energy Savings: £2,300
- 🛠 Maintenance Savings: £3,600 per year
- ⏱ Payback Period: 1.9 years
- 📈 Estimated ROI (5 years): 162%
Conclusion
The PowerFlex 525 upgrade modernised the customer’s conveyor system, providing smoother starts, faster changeovers, lower maintenance costs, and improved energy efficiency. The drives’ integrated Ethernet/IP connectivity enabled predictive maintenance and remote diagnostics — key elements of the company’s digital transformation initiative.
Whether you manage packaging conveyors, material-handling systems, or industrial lines, upgrading to Allen Bradley PowerFlex drives can deliver immediate operational and financial gains. Use our engineering tools to design your own retrofit:
- ⚙️ VFD Sizing Calculator
- ⚙️ Cable Sizing Calculator
- ⚙️ Braking Resistor Calculator
- ⚙️ Motor Starter Selection Calculator
Explore our full range of Allen Bradley VFDs including PowerFlex 523, 525, and 755 models — all in stock for next-day UK delivery and backed by a 2-year warranty.
At Drive Outlet Megastore, we specialise in OEM automation equipment at unbeatable prices. Contact our expert team today for help specifying your next PowerFlex upgrade.
