Industrial Modernization: Accuracy and Energy Gains with Electric Actuators

Industrial Modernization: Accuracy and Energy Gains with Electric Actuators

In the Brazilian industrial scenario, the search for operational efficiency and competitiveness is constant. The modernization of automation systems, in particular the replacement of pneumatic controls with electric actuators, is no longer an option and has become a strategic necessity. Factors such as the growing demand for precision, the obsolescence of replacement parts for legacy systems, and stringent safety and energy efficiency regulations are driving this transition.

Pneumatic actuators, although robust and reliable in many historical applications, have inherent control and power consumption limitations. Electrical systems offer an alternative with superior control, accurate positioning and digital communication capabilities, fundamental to Industry 4.0. UNITEC-D GmbH, with its vast experience in MRO and engineering, supports Brazilian industry in the evaluation and implementation of these advanced solutions.

Assessment of Legacy Systems: Criteria for Retrofit

Before starting any modernization project, it is essential to carry out a comprehensive technical assessment of existing pneumatic systems. This analysis determines the economic and operational feasibility of the transition. The main criteria for this assessment include:

Modern Alternatives: Pneumatic vs. Electrical Actuation

The choice between pneumatic systems and electric actuators must consider the specific demands of the application, as well as performance and sustainability requirements. The following table compares the technical attributes of both systems, highlighting the advantages of modern electric actuators, such as the DANFOSS 052F4044 for proportional valves, when adapted to linear or rotary actuation functions through appropriate mechanical design.

The DANFOSS 052F4044 electric actuator is a frequently used component in proportional valve control systems. By considering it as an example of modern technology, it exemplifies the trend towards more compact solutions, with greater control and lower energy demand. UNITEC-D offers a full range of compatible electric actuators, drives and controllers, including solutions equivalent or superior in performance to the 052F4044 for various applications.

Calculation of Return on Investment (ROI)

The decision to modernize an industrial park must be based on a detailed financial analysis. Let's consider a hypothetical scenario in a medium-sized factory in Brazil, which uses 20 pneumatic actuators in a production line operating 24 hours a day, 300 days a year (7,200 hours/year). The cost of industrial electrical energy is R$0.70/kWh.

Current Cost of the Pneumatic System:

• Energy Consumption: A 50 kW compressor serving 20 actuators (with an efficiency of 20%) has a high primary energy cost. Assuming that the compressor operates 70% of the time to maintain pressure, consumption is 50 kW * 0.70 * 7200 h/year = 252,000 kWh/year.
• Annual Energy Cost (Pneumatic): 252,000 kWh * R$0.70/kWh = R$176,400.00.
• Preventive and Corrective Maintenance: We estimate 100 hours/year of maintenance (leaks, filter changes, lubrication) at a cost of R$80/hour for labor. Annual Cost: 100 h * R$80/h = R$8,000.00.
• Cost of Replacement Parts: R$ 10,000.00/year (seals, hoses, valves).
• Downtime (Production Loss): With an MTBF of 5,000 hours per actuator, and 20 actuators, we have 20 * (7200 / 5000) = 28.8 significant failures per year. Assuming an average of 2 hours of downtime per failure. Total downtime: 57.6 hours/year. Downtime cost: 57.6 h * R$ 1,500.00/h = R$ 86,400.00.
• Total Annual Cost of the Pneumatic System: R$176,400 + R$8,000 + R$10,000 + R$86,400 = R$280,800.00.

Cost of the New System with Electric Actuators:

• Initial Investment:
  • 20 electric actuators (equivalent) with drivers: 20 * R$6,000.00/actuator = R$120,000.00.
  • Installation and commissioning cost: 20 * R$ 1,000.00/actuator = R$ 20,000.00.
  • PLC programming and integration: R$ 15,000.00.
  • Total Investment: R$120,000 + R$20,000 + R$15,000 = R$155,000.00.
• Power Consumption: Electric actuators are significantly more efficient. Assuming an average consumption of 0.5 kW per actuator in operation (considering cycles and peaks), and 20 actuators. Total consumption: 20 * 0.5 kW * 7200 h/year = 72,000 kWh/year.
• Annual Energy Cost (Electric): 72,000 kWh * R$0.70/kWh = R$50,400.00.
• Preventive and Corrective Maintenance: Minor. We estimate 20 hours/year at R$80/hour. Annual Cost: 20 h * R$80/h = R$1,600.00.
• Cost of Replacement Parts: R$2,000.00/year (cables, connectors).
• Downtime (Production Loss): With an MTBF of 50,000 hours per actuator, and 20 actuators, we have 20 * (7200 / 50000) = 2.88 significant failures per year. Assuming an average of 1 hour of downtime per failure (quicker to diagnose). Total downtime: 2.88 hours/year. Downtime cost: 2.88 h * R$ 1,500.00/h = R$ 4,320.00.
• Total Annual Cost of the New System: R$50,400 + R$1,600 + R$2,000 + R$4,320 = R$58,320.00.

Economy and Payback Analysis:

• Total Annual Savings: R$280,800 (pneumatic) - R$58,320 (electric) = R$222,480.00.
• Payback Period (Return on Investment): R$155,000 (initial investment) / R$222,480 (annual savings) ≈ 0.7 years (approximately 8.4 months).

This calculation demonstrates that the investment in electric actuators can have a financial return in less than a year, mainly due to significant energy savings and the drastic reduction in maintenance costs and downtime. The "the old system still works" objection is validated by Total Cost of Ownership (TCO) analysis, which reveals that operating the obsolete pneumatic system generates ongoing financial losses that far exceed the cost of an efficient new system.

Additionally, modernization contributes to compliance with energy efficiency and safety guidelines. The European Ecodesign Directive (2009/125/EC), although not directly applicable in Brazil, sets a precedent for the optimization of energy-related products, influencing global technological development and encouraging the industry to seek more efficient solutions.

Implementation Roadmap: Minimizing Disruption

Careful planning is critical for a smooth transition from pneumatic to electric systems, minimizing production disruptions. The roadmap can be divided into strategic phases:

1. Phase 1: Planning and Engineering (2-4 weeks)
   • Detailed survey of existing actuators and application requirements (force, speed, stroke, cycles).
   • Selection of suitable electrical actuators and their respective drivers (Ex: DANFOSS family or equivalent).
   • Electrical (ABNT NBR 5410, NR-10) and mechanical design (interface adaptation) of the new system.
   • Risk analysis (ABNT NBR ISO 13849, NR-12) and safety plan.
   • Development and validation of the PLC program for new actuators.
   • Detailed budget and schedule.
2. Phase 2: Acquisition and Preparation (4-8 weeks)
   • Purchase of electrical actuators, drivers, cables, safety components and electrical panels. UNITEC-D provides all necessary components.
   • Pre-assembly of subassemblies and electrical panels in a separate location to reduce installation time in the plant.
   • Training the maintenance and operation team on the new systems.
3. Phase 3: Installation and Integration (1-2 weeks per line/area)
   • Gradual retirement of legacy pneumatic actuators in phases, per section of production line or machine.
   • Physical installation of new electrical actuators and their drivers.
   • Electrical and communication connection (Ethernet/IP, PROFINET, etc.) to the existing or new PLC.
   • Initial wiring and safety check.
4. Phase 4: Commissioning and Optimization (1 week per line/area)
   • Functionality and safety tests (NR-12 compliance).
   • Calibration and fine-tuning of control parameters (speed, acceleration, force).
   • Factory acceptance tests (FAT) and site acceptance tests (SAT).
   • Performance optimization for maximum efficiency and accuracy.

Technical Challenges and Solutions in Modernization

Replacing pneumatic systems with electric actuators can present specific challenges. Anticipation and adequate planning are crucial to mitigate risks:

• Mechanical Compatibility: The mounting interface of pneumatic actuators may be different.

  Solution: Design and manufacture custom adapter plates or brackets. UNITEC-D offers engineering services for the development of mechanical solutions.

• Control Integration: Migration from discrete I/O to serial or network communication (Ethernet/IP, PROFINET, Modbus TCP) requires updating the PLC or interface modules.

  Solution: Use modern PLCs with network communication capabilities or protocol gateways. Ensure that the selected actuator drivers are compatible with the existing or planned automation network protocol.

• Incorrect Sizing: Errors in calculating force, speed and stroke can lead to premature failures or inadequate performance.

  Solution: Carry out rigorous sizing based on the application's load curves and work cycles. Consider safety factors. Specialized consultancy from UNITEC-D can guarantee correct sizing.

• Thermal Management: Electric actuators, especially in intense duty cycles, can generate heat.

  Solution: Ensure adequate ventilation, consider heat sinks or actuators with forced cooling. Monitor operating temperature to avoid performance degradation.

• Current Spikes: Electric motors can generate current spikes during starting or reversing, impacting the electrical grid.

  Solution: Use drivers with vector control and soft start functions. Properly size circuit breakers and cables in accordance with ABNT NBR 5410.

Case Study: Automotive Assembly Line Optimization

A large automotive manufacturer in São Paulo was facing problems with 30 pneumatic actuators on its body assembly line, responsible for indexing and fixing parts. The KPIs before modernization were:

• Positioning Accuracy: ±1.8 mm, causing rework in 5% of parts.
• Annual Downtime: 120 hours (due to seal and valve failures).
• Energy Consumption (Pneumatic): R$250,000.00/year for the section.
• MTBF: 4,500 hours/actuator.

UNITEC-D proposed replacing the 30 pneumatic actuators with high-precision electric actuators with servo drive, integrated via EtherCAT to a Siemens S7-1500 PLC. The total investment was R$220,000.00.

Post-Modernization Results (After 12 Months):

• Positioning Accuracy: ±0.03 mm, eliminating rework related to positioning.
• Annual Downtime: Reduction to 15 hours (planned maintenance only).
• Energy Consumption (Electrical): R$60,000.00/year for the section.
• MTBF: Increased to 60,000 hours/actuator.

Success KPIs:

• Rework Reduction: 100% in positioning failures.
• Energy Savings: R$190,000.00/year.
• Increased Line Availability: 105 annual hours of additional production.
• Payback: The investment was recovered in approximately 13.9 months (220,000 / 190,000).

This case study confirms that retrofitting with electric actuators provides tangible improvements in product quality, energy efficiency and operational reliability, with a proven return on investment.

Commissioning and Validation: Ensuring Performance

The commissioning phase is critical to ensure that new electric actuators perform according to design specifications and safety requirements. This process involves:

• Functional Tests: Check all movement sequences, speeds, forces and positioning. Perform full cycles of operation to validate repeatability and accuracy.
• Safety Tests: Confirm the performance of safety devices (emergency stop, light barriers, safety relays) in accordance with NR-12 and ABNT NBR ISO 13849.
• Vibration and Noise Analysis: Monitor vibration and noise levels to ensure they are within acceptable limits specified by the manufacturer, and in compliance with occupational health standards.
• Temperature Monitoring: Perform temperature measurements on actuators and drivers during peak operation to ensure there is no overheating.
• Parameter Logging: Document all configuration, calibration and performance parameters for future reference and traceability.
• Acceptance Tests: Perform customer acceptance tests (SAT), validating the agreed KPIs (accuracy, speed, cycle time).
• Post-Installation Training: Reinforce the training of the maintenance and operation team for the correct use and diagnosis of the new system.

Conclusion

The strategic replacement of pneumatic systems by electric actuators represents an imperative for Brazilian industry that seeks modernization, sustainability and greater competitiveness. Accuracy gains, superior energy efficiency, reduced maintenance costs and compliance with regulatory standards such as NR-10 and NR-12 fully justify the initial investment. UNITEC-D GmbH is your ideal partner, offering not only high-quality components such as actuators and drivers, but also specialized technical support for each step of the modernization process.

To explore our full line of electric actuators and automation solutions, and boost your plant's efficiency, visit the UNITEC-D E-Catalog.

References

• ABNT NBR 5410: Low voltage electrical installations. Brazilian Association of Technical Standards.
• ABNT NBR ISO 13849-1: Machine safety — Safety-related parts of control systems — Part 1: General principles for design. Brazilian Association of Technical Standards.
• Regulatory Standard NR-10: Safety in Electrical Installations and Services. Ministry of Labor and Employment of Brazil.
• Regulatory Standard NR-12: Workplace Safety in Machines and Equipment. Ministry of Labor and Employment of Brazil.
• Directive 2009/125/EC of the European Parliament and of the Council of 21 October 2009 on the establishment of a framework for defining ecodesign requirements.
• DANFOSS. Technical catalogs of actuators and proportional valves.