IEC 62061 Functional Safety of Electrical Control Systems
IEC 62061 "Functional Safety of Safety-Related Electrical, Electronic and Programmable Electronic Control Systems for Machinery" is a key technical specification for the crane industry. As an international standard dedicated to the functional safety of electrical control systems in machinery, it builds on the principles of IEC 61508 while focusing specifically on machinery applications. The standard systematically defines the full lifecycle requirements for the design, integration, and verification of electrical safety control systems used in cranes and other lifting equipment.
It provides a unified technical basis for design personnel, inspection bodies, and end users. Kelude strictly implements the technical requirements of this standard throughout its product development and manufacturing processes, ensuring compliance and reliability.
Scope and Application of the Standard
IEC 62061 sets out the technical requirements and safety indicators for electrical safety in lifting appliances, covering all types of cranes with a rated lifting capacity above 0.5 t. The standard applies not only to the design and manufacturing of new equipment but also provides clear technical guidance for the inspection, maintenance, and modification of cranes already in service. As a key component of the crane standard system, it works in coordination with the EN 13001 Crane Safety Standard series and ISO 4309 Wire Rope Inspection Standard to form a comprehensive framework of technical specifications. The clearly defined technical parameters and safety factors give design personnel a solid design basis, while also offering third-party inspection bodies quantifiable acceptance criteria for type tests and factory acceptance tests.
Core Technical Parameter Framework
Under IEC 62061, the design and manufacturing of safety-related electrical control systems must meet a strict set of technical parameters. These values are derived from extensive test data and safety engineering principles, covering everything from material selection to structural design. The safety factor ranges specified in the standard account for the fatigue life and limit load conditions that cranes experience under demanding operating environments. In practice, design personnel must select the appropriate parameter combinations based on the equipment's work duty classification, load spectrum, and intended application. The parameter cards below summarize the core technical indicators defined by the standard:
Comparative Analysis of Key Technical Parameters
The comparison table below systematically contrasts the core parameters specified in IEC 62061 with common engineering practice. All values shown are either mandatory or recommended requirements of the standard and should be strictly implemented during design and selection as well as factory acceptance testing.
| Item | technical requirements | Description |
|---|---|---|
| Safety Integrity Level (SIL) | SIL2/CL2(cranesafety function) | CLas SILfor Machineryrenaming of |
| PFHd Requirement | SIL2:1×10⁻⁷~1×10⁻⁶/h | of safety-related functionsprobability of failure |
| Architectural Constraints | HFT=1(dual channel1oo2) | single channelshall DC≥99%in order to SIL2 |
| Diagnosis Function | DC≥90%(SIL2Recommended) | including periodic self-test and comparison |
| safety function Identification | overload/Overspeed/limit switch/emergency stop/Interlock | item-by-item Identificationand set SILr |
| Verification Interval | SILVerification+functional test | design Phase+Operational Phase |
Inspection Requirements and Intervals
IEC 62061 sets out clear inspection requirements for the electrical control of machinery, covering Factory Acceptance Test, Type Test, and periodic inspection. The Factory Acceptance Test must be performed on every unit at the manufacturer's facility by the quality inspection department, and each unit that passes must be accompanied by a detailed inspection report and a certificate of conformity. For equipment in service, the periodic inspection interval is determined by the work duty and operating environment, and generally must not exceed 12 months.
| Item | technical requirements | Description |
|---|---|---|
| safety function Verification | item-by-itemsafety function Testing | Annual+Validation SILrcomply with |
| PFHd Calculation | reliability Block Diagram/Fault Tree | Annual+recalculation upon change |
| diagnostic coverage Testing | fault injection verification Detection Rate | Annual+DC≥90% |
| Change Management | Safety Impact Assessment+Re-verification | per change execution |
Safe Operation and Management Requirements
Safe operation and routine management play a critical role in the implementation of IEC 62061. The standard places strong emphasis on operator qualification and training, requiring that all operators complete specialized training and obtain the necessary certification before assuming their duties. User units are expected to establish a robust equipment file management system that documents the full installation, use, maintenance and inspection history of each machine. Any safety hazard identified must be addressed through the rectification procedure specified in the standard, ensuring the equipment remains safe and controllable at all times. Additionally, the standard imposes restrictive requirements on equipment operation under extreme operating conditions.
FAQ
Q: What is the relationship between IEC 62061 and IEC 61508, and how do they differ?
A: IEC 62061 is the machinery-sector application standard derived from IEC 61508, retaining the Safety Integrity Level (SIL) concept in a more streamlined form. IEC 61508 is a generic standard applicable across all industries, whereas IEC 62061 specifically addresses electrical control systems for machinery, including cranes. Both standards share the same SIL classification, PFH calculation methodology, and safety lifecycle requirements, but IEC 62061 offers design examples and implementation guidance tailored to the machinery industry.
Q: How is the SIL rating determined for crane safety functions?
A: The SIL rating is determined using the risk parameter assessment method: severity (Se: 4 levels), exposure frequency (Fr: 5 levels), probability of avoidance (Pr: 3 levels), and probability of occurrence (Av: 3 levels). SILr = Se + Fr + Pr + Av − 6. Overload protection and emergency stop functions on cranes typically require SIL2 (score range 14–17). Kelude Heavy Industry follows this standardized methodology to identify each safety function and determine its corresponding SILr.
Q: What is the calculation method for safety function verification?
A: PFHd is calculated using reliability block diagrams (RBD) or fault tree analysis (FTA). For a dual-channel 1oo2 architecture, PFHd = 2·PFHd_ch·(1−DC)²·β + PFHd_ch·DC·β/2, where β is the common cause failure factor (typically taken as 10%) and DC is the diagnostic coverage. The calculated PFHd value confirms whether the system meets the SIL2 range of 1×10⁻⁷ to 1×10⁻⁶.
Q: What is the management process for safety-related changes?
A: Any change affecting a safety function must follow this sequence: change request → safety impact analysis → solution design → safety assessment → approval → implementation → verification testing → update of safety documentation. The impact analysis must assess whether the change alters the SIL rating, introduces new failure modes, or affects diagnostic functions. Kelude's change management process covers the entire product lifecycle.
— Dedicated to crane design and manufacturing, our products strictly comply with the IEC 62061 standard system, offering lifecycle service from solution design and manufacturing and installation through after-sales maintenance. For details on how this standard is applied in our products, contact our technical team for comprehensive technical documentation.
