Ensuring Safety and Reliability: Application of Safety Light Barriers in Airport Baggage Handling Systems

Introduction

The efficiency of the operation of modern airports largely depends on the reliability and safety of baggage handling systems (BAG). These complex automated complexes, consisting of thousands of moving parts, conveyors, sorting machines and robotic devices, play a critical role in passenger logistics. Any failure or unplanned outage at the SOB can lead to significant financial losses, flight delays, and a decrease in passenger satisfaction. In addition, the high degree of automation and speed of movement of system elements create potential risks for operating personnel. Accordingly, the implementation of high-quality components and strategic approaches to maintenance, repair and operation (MRO) is a prerequisite for maintaining the smooth and safe operation of SOB.

UNITEC-D GmbH, with more than 20 years of experience in M&R and 10 years in engineering design, offers solutions that meet the highest industry standards, in particular for Ukrainian industrial production.

Critical Components in Baggage Handling Systems

Baggage handling systems require the use of a wide range of high-tech components, each of which performs a specific function. The main component we will look at in this analysis is a safety light barrier, such as the Telemecanique VZ3TP2540M16. This device is an integral part of safety systems that prevent access to dangerous areas and protect personnel from injury.

Telemecanique VZ3TP2540M16: Safety Light Barrier

• Purpose: VZ3TP2540M16 is a type 4 optical light barrier consisting of a transmitter and a receiver. Its function is to detect the presence of objects or people in a defined area, which ensures an immediate stop of dangerous movement of machines.
• Technical characteristics:
  • Height of the protective field: 540 mm.
  • Resolution: 30 mm, which allows you to detect fingers or hands.
  • Maximum working distance: up to 12 meters.
  • Response time: less than 15 ms.
  • Protection class: IP65, which ensures resistance to dust and water jets, which is important in industrial environments.
  • Compliance with standards: EN 61496-1 (Electro-sensitive protective equipment), EN ISO 13849-1 (Safety of machines - Parts of control systems related to safety), as well as CE and UkrSEPRO requirements.
• Application: VZ3TP2540M16 VZ3TP2540M16 are installed at access points to conveyor lines, near sorting machines, at entrances to service areas, where there is a risk of being pinched or struck by moving elements.

Other Critical Components:

1. Motor-reducers: Provide movement of conveyor belts and sorting mechanisms. For example, motor-reducers from the companies SEW-EURODRIVE or NORD, which meet the standards EN 60034 (Rotating electrical machines) and have the energy efficiency class IE3 according to IEC 60034-30-1. Typical power: 0.75 kW - 11 kW, rotation speed: 50-200 rpm.
2. Proximity sensors and photoelectric sensors: Used to detect the presence of luggage, control its position and speed. For example, inductive sensors from Sick or Pepperl+Fuchs (correspondence EN 60947-5-2), which ensure activation accuracy up to ±0.1 mm.
3. Programmable logic controllers (PLCs): The central control element of the entire system, which processes signals from sensors and controls actuators. PLCs from Siemens (e.g. SIMATIC S7 series) or Rockwell Automation (Allen-Bradley) are industry standards that comply with EN 61131-2.
4. Frequency converters (IF): Control the speed and torque of geared motors, ensuring smooth start, stop and energy efficiency. Inverters from Schneider Electric (Altivar series) or Danfoss (VLT series) with a power range from 0.37 kW to 45 kW, complying with EN 61800-3 (Variable Speed ​​Electric Drive Systems).
5. Conveyor belts: Made of different materials (PVC, rubber, polyurethane) depending on the load and operating conditions. Compliance with ISO 21184 (Textile Conveyor Belts) is important. Typical movement speed: 0.5 – 3.0 m/s.

Typical Technological Process and Location of Components

The baggage handling system at the airport is a sequence of interconnected stages:

1. Check-in and Baggage Reception: Passengers hand in their luggage at the check-in counters. Baggage is placed on conveyor belts, where it is weighed and scanned (X-ray scanners). Proximity sensors control the flow of luggage.
2. Sorting: Baggage is moved to the central sorting area, where its destination is determined using barcode scanners or RFID tags. Sorting mechanisms (for example, cross-belt or tilt-tray sorters) direct the baggage to the appropriate lines. VZ3TP2540M16 safety light barriers are installed at the entrances to the sorting machines, as well as in the overload areas, to protect personnel.
3. Transportation: Baggage is transported via a network of conveyor belts to the appropriate terminals or aircraft loading areas. Motor-reducers and inverters provide controlled movement of the belts. Proximity sensors monitor the passage of luggage, and a PLC manages all the logic of movement.
4. Loading: Baggage is fed on a carousel or directly to aircraft loaders. Safety light barriers are also required in these areas where personnel interact with moving parts.

The VZ3TP2540M16 safety light barriers are integrated into the control system by connecting to PLC safety modules (for example, Siemens F-CPU). When the light beam is interrupted, the system generates an emergency stop signal, instantly cutting off the power supply to dangerous mechanisms according to safety category PL d or PL e according to EN ISO 13849-1.

Failure Modes and Impact on Downtime

Component failures in the SOB have a direct impact on the operational efficiency and financial performance of the airport. The cost of airport downtime can range from 5,000 to €25,000 per hour for critical areas of the system, depending on the size of the airport and the number of delayed flights.

Typical Failure Modes:

• Safety Light Barriers (VZ3TP2540M16):
  • Optics Contamination: Dust, dirt, condensation can obstruct the passage of light rays, causing false starts and unplanned shutdowns.
  • Misalignment: Mechanical vibrations or shocks can cause the transmitter or receiver to misalign, disrupting beam alignment.
  • Cable damage: Mechanical damage to power cables or signal cables.
  • Internal failure: Failure of electronic components due to voltage fluctuations or natural wear and tear. Mean time before failure (MTBF) for such devices is about 80,000 hours.
• Gear motor:
  • Bearing wear: Leads to increased noise, vibration and overheating.
  • Oil leakage: Reduces lubrication efficiency, accelerates gear wear.
  • Overheating of windings: May be caused by overload or inverter failure.
• Conveyor belts:
  • Tears or punctures: Due to mechanical damage or aging of the material.
  • Skid: Due to incorrect tension or wear of the drive drums.
• Sensors:
  • Contamination: Similar to light barriers, dirt can affect trigger accuracy.
  • Mechanical damage: Hit by luggage or equipment.

Strategies of Preventive and Predictive Maintenance

In order to minimize downtime and ensure uninterrupted operation of the SOB, two main maintenance strategies are used:

Preventive Maintenance (PO)

The software is based on scheduled intervals and is executed regardless of the actual state of the equipment.

• Advantages: Simple planning, reducing the probability of sudden failures.
• Disadvantages: It is possible to perform unnecessary work, increased maintenance costs, potential shutdowns of equipment for maintenance, even if it is working.
• Measures for VZ3TP2540M16:
  • Weekly visual inspection for damage and contamination.
  • Monthly cleaning of the optical surfaces of the transmitter and receiver using the means recommended by the manufacturer.
  • Quarterly alignment check and test run using calibration patterns.
  • Annual check of integrity of cables and reliability of electrical connections.
• Measures for other components: Regular lubrication of motor-reducer bearings (every 2000 hours of operation), checking the tension of conveyor belts (monthly), calibration of sensors (once every six months).

Predictive Service (PR)

PRO uses equipment condition monitoring data to predict failures and plan M&R only when necessary.

• Advantages: Optimization of service intervals, reduction of the number of unplanned downtimes, reduction of M&R costs, increase of equipment service life.
• Disadvantages: Requires investment in monitoring and data analysis systems, qualified personnel.
• Measures for VZ3TP2540M16:
  • Light barrier signal level monitoring. A drop in level may indicate contamination or misalignment before complete failure occurs.
  • Integration into the control system to collect data on the number of actuations and response time, allowing wear to be evaluated.
• Measures for other components:
  • Vibration analysis: For geared motors to detect bearing wear or imbalance.
  • Thermography: Detection of overheating of motor windings or problems with electrical connections.
  • Lubricant analysis: For gearboxes to detect the presence of metal particles, which indicates wear.
  • Motor current monitoring: Detection of abnormal loads or mechanical problems.

The combination of both strategies (Time-Based Maintenance for basic checks and Condition-Based Maintenance for critical nodes) provides an optimal balance between costs and reliability.

Practical Example: Failure of the Safety Light Barrier

Let's consider the scenario at the Boryspil airport terminal, where a Telemecanique VZ3TP2540M16 safety light barrier is installed on a high-speed baggage sorting line moving at a speed of 2.5 m/s. This barrier protects the area where staff can access to correct stuck luggage.

Situation:

At 08:30 in the morning, during the peak load, the SOB system suddenly stops. A message appears on the PLC control panel: "Emergency stop: Interruption of safety light barrier Zone C3". This brings the entire sorting line to a halt, processing up to 1,500 pieces of luggage per hour. The cost of downtime is estimated at 12,000 euros per hour.

Analysis and Troubleshooting:

1. Initial inspection (08:35): M&E engineer arrives on site. A visual inspection of the VZ3TP2540M16 shows a significant accumulation of dust and fine particles on the optical lenses of the transmitter and receiver. This was probably the cause of the false alarm.
2. Cleaning attempt (08:40): An engineer cleans the lenses using a special solution and a microfiber cloth. After cleaning, the system restarts.
3. Stop again (08:50): After 10 minutes the system stops again with the same error. This indicates that the problem is not only surface contamination or insufficient cleaning. Possible misalignment or internal defect.
4. Diagnostics (08:55): Using the diagnostic tool, the engineer checks the signal level. It was found that even after cleaning, the signal level on the receiver is lower than the permissible minimum, and the barrier does not always react correctly during test operation. This indicates an internal fault or significant misalignment that cannot be corrected by simple cleaning.
5. Replacement decision (09:05): A decision is made to replace the defective VZ3TP2540M16 with a new, certified component from the spare parts warehouse.
6. Replacement and Calibration (09:15 - 09:45): The new light barrier is installed. Accurate alignment of the transmitter and receiver is carried out, as well as a test operation according to EN 61496-1. The integration with the PLC and the absence of errors are checked.
7. Restoration (09:50): The SOB system restarts successfully. Sorting line resumes operation.

Result: Total downtime: 1 hour 20 minutes. Estimated losses: 16,000 euros. This case highlights the critical importance of having certified spare parts and qualified personnel available for prompt troubleshooting.

Management of Spare Parts for SOB

Effective management of spare parts is a key factor in minimizing downtime and optimizing M&R costs. It is recommended to use a strategy based on the criticality of components for SOB.

Categorization of Spare Parts:

• Category A (Critical): Components with high downtime cost, long lead time and high probability of failure. These parts must always be in stock. Example: Gearmotors, PLCs, safety light barriers (like VZ3TP2540M16). Recommended stock level: 1-2 units.
• Category B (Important): Components that may cause a simple but less critical or shorter delivery time. Example: Proximity sensors, IF (spare modules), relays, cables. Recommended stock level: 2-3 units.
• Category C (Expendable): Low cost, readily available, low impact simple components. Example: Fuses, indicator lamps, small mechanical parts, cleaning materials. Recommended stock level: 5+ units.

Recommendations:

• Use of original or certified analogues: To ensure compatibility, reliability and compliance with standards (CE, UkrSEPRO). This is especially important for safety components such as the VZ3TP2540M16.
• Optimizing inventory levels: Using historical data on failures and lead times to determine optimal inventory levels to avoid both overspending and shortages.
• Centralized warehouse: Efficient storage and inventory management, allowing you to quickly find and issue the required components.
• Establishing partnerships with suppliers: Reliable suppliers such as UNITEC-D GmbH can provide fast delivery of critical components and technical support.

Conclusion

Baggage handling systems at airports are complex, highly automated complexes that require flawless operation of each component. The use of safety light barriers like the Telemecanique VZ3TP2540M16 is critical to protecting personnel and ensuring uninterrupted operations. Effective preventive and predictive maintenance strategies, together with carefully thought-out spare parts management, are the basis for minimizing downtime and optimizing operational costs.

UNITEC-D GmbH is a reliable partner that supplies certified components and expert knowledge in the field of M&R, contributing to increasing the reliability and safety of industrial equipment in Ukraine.

For more information on components and solutions for baggage handling systems, visit the UNITEC-D E-Catalog.

Link

• DSTU EN 60204-1:2018. Machine safety. Electrical equipment of machines. Part 1. General requirements (EN 60204-1:2018, IDT).
• EN 61496-1:2013. Safety of machinery. Electro-sensitive protective equipment. Part 1: General requirements and tests.
• EN ISO 13849-1:2015. Safety of machinery. Safety-related parts of control systems. Part 1: General principles for design.
• IEC 60034-30-1:2014. Rotating electrical machines. Part 30-1: Efficiency classes of line operated AC motors (IE code).
• EN 60947-5-2:2007. Low-voltage switchgear and controlgear. Part 5-2: Control circuit devices and switching elements. Proximity switches.
• EN 61131-2:2017. Programmable controllers. Part 2: Equipment requirements and tests.
• EN 61800-3:2018. Adjustable speed electrical power drive systems. Part 3: EMC product standard including specific test methods.
• ISO 21184:2015. Conveyor belts with a textile carcass. Dimensions and quality requirements.