IEC 61869-13-2021 PDF

Full title and description

Instrument transformers - Part 13: Stand‑alone merging unit (SAMU) (IEC 61869‑13:2021). This product standard specifies additional technical and testing requirements for stand‑alone merging units (SAMUs) that accept standardized analogue inputs from instrument transformers and provide a digital interface (in conjunction with IEC 61869‑9). It covers ratings, design, insulation, accuracy, electromagnetic compatibility, environmental and safety tests, and installation/maintenance rules for SAMUs used in AC power applications (15 Hz to 100 Hz).

Abstract

IEC 61869‑13:2021 defines requirements specific to stand‑alone merging units (SAMUs) that convert standardized analogue outputs of instrument transformers (for example 1 A, 5 A, 3.25 V/√3, 100 V/√3) into a digital form compatible with IEC 61869‑9 and the IEC 61850 architecture. The standard supplements the general and product‑specific requirements of the IEC 61869 series and excludes digital output format details and cybersecurity, which are covered in IEC 61869‑9 and IEC 62351 respectively.

General information

• Status: Published / Current (EN/IEC adoption).
• Publication date: 2021 (published July/August 2021; IEC release July 2021).
• Publisher: International Electrotechnical Commission (IEC); also published/adopted as EN IEC by regional bodies.
• ICS / categories: 17.220.20 — Measurement of electrical and magnetic quantities.
• Edition / version: Edition 1.0 (IEC 61869‑13:2021).
• Number of pages: Typically published at approximately 141 pages (page count varies by national/adopted editions; some national documents list ≈73–74 pages for certain formatted versions).

Scope

This part of IEC 61869 is a product standard giving additional requirements for stand‑alone merging units (SAMUs) used in AC power systems with rated frequencies from 15 Hz to 100 Hz. It applies to SAMUs that receive standardized analogue inputs from instrument transformers compliant with the IEC 61869 series (and related standards) and prepare these signals for conversion to digital outputs compliant with IEC 61869‑9. The standard does not define the digital output format itself nor cover cybersecurity requirements.

Key topics and requirements

• Definitions and normative references for SAMU design and testing.
• Normal and special service conditions (environmental/ambient limits).
• Ratings: input types (1 A, 5 A, low‑power VT inputs, specified voltage/current ranges), rated frequency range.
• Design and construction: electrical, mechanical and insulation requirements for reliable analogue‑to‑digital front ends.
• Accuracy and measurement chain considerations, including annex material on measurement chain accuracy classes.
• Tests: type and routine tests covering accuracy, insulation, surge/switching withstand, EMC, environmental, temperature and vibration.
• Rules for transport, storage, erection, operation and maintenance and safety requirements.
• Interoperability requirements with IEC 61869‑9 (digital interface / IEC 61850 mapping) and compatibility notes with switchgear controllers and IEDs.

Typical use and users

Primary users include utility engineers, protection and metering equipment manufacturers, switchgear vendors, testing and certification laboratories, system integrators, and consultants involved in substation measurement and digital protection/automation. The standard supports procurement, type testing, conformity assessment, and interoperability of SAMUs in digital substation architectures.

Related standards

IEC 61869 series (general requirements and product parts), especially IEC 61869‑1, ‑2, ‑6 and ‑9; IEC 61850 (substation communication and data models) as applied via IEC 61869‑9; IEC 62351 (cybersecurity for power systems) for security practices; related legacy standards and references such as IEC 60044 series, IEC 60185/60186 and IEEE C57.13 where relevant.

Keywords

SAMU, stand‑alone merging unit, instrument transformer, IEC 61869, digital interface, IEC 61850, metering, protection, low‑power instrument transformer, accuracy class, EMC, insulation, type tests.

FAQ

Q: What is this standard?

A: IEC 61869‑13:2021 is Part 13 of the IEC 61869 series and defines additional requirements for stand‑alone merging units (SAMUs) that interface analogue outputs of instrument transformers to digital systems.

Q: What does it cover?

A: It covers ratings, design and construction requirements, testing (accuracy, insulation, EMC, environmental), installation/maintenance rules and safety provisions for SAMUs used in AC power applications (15 Hz to 100 Hz). It does not standardize the digital output format (see IEC 61869‑9) and does not include cybersecurity requirements (see IEC 62351).

Q: Who typically uses it?

A: Utilities, protection/metrology engineers, manufacturers of SAMUs and instrument transformers, switchgear suppliers, testing bodies and integrators implementing digital substations and metering/protection systems.

Q: Is it current or superseded?

A: IEC 61869‑13:2021 was published in 2021 and is listed as a current/published standard in national adoptions (EN/IEC). There is no widely published replacement or newer edition recorded in major standards catalogs as of the time this summary was prepared. If you need an authoritative up‑to‑date status for procurement or compliance, check the IEC and your national standards body for any amendments or corrigenda.

Q: Is it part of a series?

A: Yes — it is one part of the IEC 61869 series (Instrument transformers). It is intended to be used together with other parts of the series, notably IEC 61869‑1 (general requirements), IEC 61869‑6 (low‑power instrument transformers) and IEC 61869‑9 (digital interface).

Q: What are the key keywords?

A: SAMU, stand‑alone merging unit, instrument transformer, IEC 61869, digital interface, IEC 61850, measurement, metering, protection, accuracy, EMC.