Multi-loop power distribution monitoring for railcar HVAC

Industry background

Rail transit has expanded widely over recent decades as part of urban public transport systems. It helps mitigate congestion, reduce environmental impact, and support urban sustainability. With advances in technology, rail systems continually adopt new techniques to improve operational efficiency, passenger comfort, energy use, and operating costs.

Monitoring the HVAC power circuits inside railcars is important for passenger comfort and safety. Real-time measurement of electrical parameters in HVAC circuits can indicate operating status, detect potential faults, and enable timely response to power issues. Monitoring data should be recorded for later analysis and trend observation to assess long-term performance and system health.

User requirements

The device is intended for continuous monitoring of HVAC distribution circuits on operating railcars. Specific requirements:

1. The train is subject to continuous vibration during operation, so the monitoring module must have high vibration resistance. Wiring terminals require screw fixation and the module must pass environmental, shock, and vibration testing.
2. Passenger density is high and many interior materials are combustible. For fire safety, the module must meet fire and flame testing requirements.
3. The module is mounted on the ceiling plate of each car, with limited installation space. It must be compact, lightweight, and support DIN-rail mounting.
4. Measure residual current for four HVAC incoming distribution circuits per car and measure load current for eight HVAC circuits.

Product description

The Acrel AMC16Z-FAL multi-current monitoring device is compact and integrates monitoring of multiple circuits. The module supports real-time acquisition of up to 24 current channels (both A and B sides combined) and four residual current channels, offering a high degree of integration compared with traditional instruments. The device has reports covering EN45545-HL3 fire safety, ISO 1716 flame testing, EN50155 type testing, TB/T3139-2021 prohibited and restricted substances, and accuracy and calibration measurement.

Dimensions

Wiring diagram

Product application

One AMC16Z-FAL module is installed on the ceiling of each car to measure four HVAC incoming circuit residual currents and eight HVAC load currents per car. All data are transmitted via RS-485 to a head-end data acquisition unit. After the train arrives at the depot, the data acquisition unit is removed and the collected data are aggregated into a central monitoring platform. Real-time monitoring of electrical parameters for HVAC distribution circuits enables assessment of HVAC operating status, detection of potential faults, and timely action on power issues to ensure HVAC system reliability.

Conclusion

Urban rail transit is a safe and environmentally friendly transport mode whose deployment continues to grow with urbanization. The Acrel multi-loop power distribution monitoring device provides circuit and residual current monitoring for railcar HVAC systems. Analysis of HVAC operating data supports evaluation of energy consumption, optimization of system design and operation, and detection of faults, contributing to energy savings, reduced operating cost, and reliable HVAC operation to maintain a safe and comfortable passenger environment.