EN 50155
| Full title | Railway applications – Rolling stock – Electronic equipment |
|---|---|
| Publisher | CENELEC |
| Scope | Electronic equipment installed on railway vehicles |
| International counterpart | IEC 60571 |
| Covers | Power supply, temperature, humidity, shock and vibration, EMC, reliability, testing |
| Related standards | EN 61373, EN 50121-3-2, EN 45545 |
EN 50155 is a European standard that specifies the requirements for electronic equipment installed on railway rolling stock: trains, trams, metros and other rail vehicles. It covers the electrical, environmental and mechanical conditions such equipment must withstand and how it must be designed, tested and documented.[1]
EN 50155 is widely used to specify industrial computers, displays, network equipment and power supplies for rail. Compliance is normally stated in a product's datasheet, often with the specific classes the product meets.
Scope
EN 50155 applies to electronic equipment for control, regulation, protection, diagnostics, energy supply and passenger information on rail vehicles. It sets requirements for:
- operation from the vehicle's power supply, including voltage variations and interruptions
- operating temperature, humidity and altitude
- shock and vibration, by reference to EN 61373
- electromagnetic compatibility, by reference to EN 50121-3-2
- design, components, reliability and expected useful life
- documentation and the tests used to show compliance
The standard has been revised several times, most notably in 2007 and 2017. The 2017 edition introduced six operating temperature classes and added reliability and rapid temperature-change testing.[1] Datasheets usually state which edition a product was tested to.
Power supply
Rail vehicles use DC supplies with nominal voltages including 24, 48, 72, 96 and 110 V. Equipment must operate continuously from 0.7 to 1.25 times the nominal voltage and withstand short variations down to 0.6 times nominal for 100 ms and up to 1.4 times nominal for one second.[1]
| Nominal | Continuous operation | Short dip (100 ms) | Short surge (1 s) |
|---|---|---|---|
| 24 V | 16.8–30 V | 14.4 V | 33.6 V |
| 48 V | 33.6–60 V | 28.8 V | 67.2 V |
| 72 V | 50.4–90 V | 43.2 V | 100.8 V |
| 96 V | 67.2–120 V | 57.6 V | 134.4 V |
| 110 V | 77–137.5 V | 66 V | 154 V |
See also: Wide-range DC input
Interruption classes
Supply interruptions occur on rail vehicles, for example when a train passes a section gap or switches power sources. EN 50155 defines classes for how equipment behaves during them:[1]
| Class | Requirement |
|---|---|
| S1 | No interruption is bridged; equipment must resume normal operation after power returns |
| S2 | Equipment operates normally through interruptions of up to 10 ms |
| S3 | Equipment operates normally through interruptions of up to 20 ms |
Riding through an interruption requires stored energy, usually capacitors in the power input, sized for the equipment's power consumption.
Operating temperature classes
Main article: Wide-temperature industrial PCs
The 2017 edition defines six operating temperature classes. OT1 and OT2 are intended for passenger and driver compartments, OT3 and OT4 for equipment in technical cabinets, and OT5 and OT6 for special applications. OT3 is the default when no class is specified.[1]
| Class | Range | Range (°F) |
|---|---|---|
| OT1 | −25 °C to 55 °C | −13 °F to 131 °F |
| OT2 | −40 °C to 55 °C | −40 °F to 131 °F |
| OT3 | −25 °C to 70 °C | −13 °F to 158 °F |
| OT4 | −40 °C to 70 °C | −40 °F to 158 °F |
| OT5 | −25 °C to 85 °C | −13 °F to 185 °F |
| OT6 | −40 °C to 85 °C | −40 °F to 185 °F |
Useful life classes
EN 50155 asks the purchaser to state how long equipment is expected to remain in service. The default is L4.[1]
| Class | Useful life |
|---|---|
| L1 | 5 years |
| L2 | 10 years |
| L3 | 15 years |
| L4 | 20 years |
Related standards
EN 50155 refers to other standards for specific requirements. A product described as EN 50155 compliant is usually also tested to these:
| Standard | Subject |
|---|---|
| EN 61373 | Shock and vibration for rolling stock equipment, by mounting location (body, bogie, axle) |
| EN 50121-3-2 | Electromagnetic compatibility of rolling stock apparatus |
| EN 45545 | Fire protection on railway vehicles, including materials and components |
| IEC 60571 | International standard for electronic equipment on rail vehicles, closely aligned with EN 50155 |
EN 50155 industrial PCs
Industrial computers built for rail typically combine:
- a power input covering one or more rail nominal voltages, often 24 to 110 V
- fanless cooling and an operating temperature class such as OT3 or OT4
- locking M12 connectors for Ethernet, power and I/O, which hold under vibration
- conformal coating on circuit boards to protect against humidity and condensation
- holdup capacitors for the required interruption class
Typical uses include passenger information systems, onboard video surveillance, train control and management, wayside monitoring and onboard Wi-Fi.
Frequently asked questions
What is EN 50155?
EN 50155 is the European standard for electronic equipment used on railway vehicles. It sets requirements for power supply tolerance, temperature, humidity, shock and vibration, electromagnetic compatibility, reliability and testing.
Is EN 50155 a certification?
EN 50155 is a standard, not a certification scheme. Manufacturers declare compliance based on testing, often performed or witnessed by a third-party laboratory. Rail operators and vehicle builders review the test reports during procurement.
What is the difference between EN 50155 and EN 61373?
EN 50155 is the overall standard for rail electronic equipment. EN 61373 covers only shock and vibration testing, and EN 50155 refers to it for those requirements.
What does OT4 mean?
OT4 is an EN 50155 operating temperature class covering −40 °C to 70 °C. It is commonly specified for equipment in technical cabinets on vehicles that operate in cold climates.
Is EN 50155 required outside Europe?
It is a European standard, but rail projects worldwide often specify EN 50155 or its international counterpart, IEC 60571, for onboard electronics.
See also
- Industrial computers
- Wide-temperature industrial PCs
- Wide-range DC input
- Shock and vibration ratings
- IEC 60068
References
- EN 50155:2017, Railway applications – Rolling stock – Electronic equipment. CENELEC.