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BS QC — Electrical Relays Quality Assessment Specifications Single-File Series Overview (3 Standards)
Covers quality assessment procedures, sectional specification for electromechanical all-or-nothing relays, and blank detail specification
📐 The BS QC series is a group of UK specifications adopting the IEC Electronic Components Quality Assessment System (IECQ), corresponding to the IEC 255 series (now IEC 61810) on electrical relays. The IECQ system implements unified quality assessment of electronic components through the hierarchy “generic specification — sectional specification — blank detail specification — detail specification”. This overview covers three BS QC specifications: quality assessment procedures (generic level), a sectional specification for electromechanical all-or-nothing relays, and a blank detail specification, covering quality assessment of electrical relays (especially electromechanical relays).
BS QC specifications follow the IECQ hierarchy: the quality assessment procedure is the generic specification, the sectional specification addresses a class of relays, and the blank detail specification provides the template for detail specifications. Select the appropriate detail specification by product class and complete quality assessment.
1. Standard List and System Framework
The three BS QC specifications covered in this overview are listed below, forming three levels of the IECQ quality assessment system.
| Reference | Title |
|---|---|
| BS QC 160000-2:1987 | Specification for electrical relays — Part 2: Quality assessment procedures |
| BS QC 160100:1987 | Specification for electrical relays — Part 19: Sectional specification — Electromechanical all-or-nothing relays |
| BS QC 160101:1987 | Specification for electrical relays — Part 19-1: Blank detail specification — Electromechanical all-or-nothing relays, test schedules 1, 2 and 3 |
2. Technical Content of Representative Standards
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BS QC 160000-2:1987 — Electrical relays: quality assessment procedures
This specification is the UK adoption of IEC 255-10, specifying quality assessment procedures for electrical relays used in the IECQ system. As a generic specification, it sets general requirements for relay quality assessment, including terminology, marking, classification of inspection and testing (qualification approval, lot-by-lot inspection and periodic inspection), sampling plans, permitted defect rates, test items and conditions, quality conformance inspection, and the issue and maintenance of certificates of conformity. It also specifies reliability assessment and failure-rate levels, and the content that the required documents (detail specifications) should contain. It provides a unified procedure for the conformity assessment of electrical relays, ensuring that relays from different manufacturers achieve a consistent quality level after assessment.
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BS QC 160100:1987 — Electrical relays: sectional specification — electromechanical all-or-nothing relays
This specification is the UK adoption of IEC 255-19, specifying the sectional specification for electromechanical all-or-nothing relays. A sectional specification addresses a class of relays (here electromechanical all-or-nothing relays, i.e. electromagnetic relays) by specifying their characteristics, tests and quality assessment requirements. It sets standard test conditions, test categories (A: climatic and mechanical; B: electrical; C: reliability), test items (contact resistance, insulation resistance, dielectric strength, operate time, release time, contact life, mechanical life, etc.), sampling and assessment procedures, and gives parameter tables to be completed in detail specifications. The sectional specification, as the bridge between the generic and blank detail specifications, ensures consistent test and assessment methods for relays of the same class.
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BS QC 160101:1987 — Electrical relays: blank detail specification — electromechanical all-or-nothing relays (test schedules 1, 2 and 3)
This specification is the UK adoption of IEC 255-19-1, specifying the blank detail specification for electromechanical all-or-nothing relays, providing test schedules 1, 2 and 3. A blank detail specification is a template for detail specifications, specifying the content to be completed, including basic relay data (contact configuration, coil voltage, contact rating, etc.), characteristic parameters, test categories and items, and the specific content of test schedules. Test schedules 1, 2 and 3 correspond to different inspection stringency and test combinations (e.g. 1 the most stringent, 3 general); manufacturers select the appropriate test schedule by product use and assessment requirements when completing the detail specification. It provides a uniform format for writing detail specifications for electromechanical relays, ensuring complete, comparable content across manufacturers and products.
3. Key Technical Points
The key technical points of the BS QC series can be summarized as follows:
| Reference | Title |
|---|---|
| 层次结构 | IECQ hierarchy: generic — sectional — blank detail — detail specification |
| 评定程序 | Qualification approval, lot-by-lot and periodic inspection, sampling plans and permitted defect rates |
| 继电器特性 | Contact resistance, insulation resistance, dielectric strength, operate/release time, contact and mechanical life |
| 试验计划 | Test schedules 1/2/3 correspond to different inspection stringency and test combinations |
The key of the IECQ system is “graded assessment” and “standardized format”: sectional and blank detail specifications unify test methods, while qualification approval and lot-by-lot/periodic inspection control batch quality, assuring quality while reducing assessment cost.
4. Engineering Practice and Application
⚡ Relay assessment: BS QC 160000-2 sets quality assessment procedures for electrical relays, being the UK implementation of the IECQ system.
🔌 Electromechanical relays: BS QC 160100 and 160101 are used for the sectional and detail specifications of electromechanical all-or-nothing relays, guiding manufacturers’ testing and conformity assessment in industrial control, automotive, telecom and power systems.
🏭 Electronic components: the IECQ system achieves worldwide mutual recognition of electronic component quality through unified assessment, reducing duplicate testing costs.
5. FAQ
Q: Q: How is the IECQ quality assessment system organized?
A: A: IECQ organizes assessment through a four-level structure: generic — sectional — blank detail — detail specification. The generic specification sets general procedures, the sectional specification addresses a class of components, the blank detail specification provides the template, and the detail specification addresses a specific product and completes assessment.
A: A: IECQ organizes assessment through a four-level structure: generic — sectional — blank detail — detail specification. The generic specification sets general procedures, the sectional specification addresses a class of components, the blank detail specification provides the template, and the detail specification addresses a specific product and completes assessment.
Q: Q: What is an “all-or-nothing” relay?
A: A: An all-or-nothing relay is one whose contact operation does not depend on the magnitude of the input: when the input reaches the operate value the contact fully operates, and when removed it fully returns — a typical electromagnetic relay.
A: A: An all-or-nothing relay is one whose contact operation does not depend on the magnitude of the input: when the input reaches the operate value the contact fully operates, and when removed it fully returns — a typical electromagnetic relay.
Q: Q: How do qualification, lot-by-lot and periodic inspection differ?
A: A: Qualification approval demonstrates the product design meets the specification (initial assessment); lot-by-lot inspection samples each batch to control batch quality; periodic inspection checks representative samples regularly for full items to verify long-term stability.
A: A: Qualification approval demonstrates the product design meets the specification (initial assessment); lot-by-lot inspection samples each batch to control batch quality; periodic inspection checks representative samples regularly for full items to verify long-term stability.
Q: Q: How do test schedules 1, 2 and 3 differ?
A: A: Test schedules 1, 2 and 3 correspond to different inspection stringency and test combinations. Usually schedule 1 is the most stringent and suits high-reliability products, while schedule 3 is general inspection; manufacturers select the schedule by product use and assessment grade when completing the detail specification.
A: A: Test schedules 1, 2 and 3 correspond to different inspection stringency and test combinations. Usually schedule 1 is the most stringent and suits high-reliability products, while schedule 3 is general inspection; manufacturers select the schedule by product use and assessment grade when completing the detail specification.
Q: Q: What items are mainly tested for electromechanical relays?
A: A: Mainly contact resistance, insulation resistance, dielectric strength, operate and release time, contact life, mechanical life, and climatic/mechanical environment tests (temperature, humidity, vibration, shock, etc.).
A: A: Mainly contact resistance, insulation resistance, dielectric strength, operate and release time, contact life, mechanical life, and climatic/mechanical environment tests (temperature, humidity, vibration, shock, etc.).