GOST 7746-89 PDF

Full title and description

GOST 7746-89 — "Current transformers. General specifications" (Russian: ГОСТ 7746-89, Трансформаторы тока. Общие технические условия). The standard establishes technical requirements, classification, test methods and acceptance rules for electromagnetic current transformers intended for measurement, protection and control in AC systems.

Abstract

GOST 7746-89 defines the general technical requirements for electromagnetic current transformers with nominal system voltages from 0.66 kV up to 750 kV inclusive, intended to supply measuring instruments, protection and control devices in 50 or 60 Hz networks. It covers classification, nominal parameters, accuracy classes, insulation and safety requirements, methods of testing (including partial discharge measurement guidance), acceptance rules, transport/storage and manufacturer guarantees. The 1989 standard replaced the earlier 1978 edition and was later superseded by GOST 7746-2001.

General information

• Status: Replaced / withdrawn (superseded by GOST 7746-2001; introduced as national/interstate but later withdrawn for the newer edition).
• Publication date: Approved 27 March 1989; came into force 1 January 1990. (Withdrawn/ended service date recorded as 1 January 2003 when the 2001 edition was adopted in Russia.)
• Publisher: Approved by the USSR State Committee for Standards (Gosstandart); published by the Standards Publishing/Издательство стандартов.
• ICS / categories: ICS/OKC code ~29.180 (power and electrical equipment; group E64 — transformers).
• Edition / version: GOST 7746-89 (1989 edition).
• Number of pages: Approximately 43 pages (typical PDF copies list 43 pages).

Scope

The standard applies to electromagnetic current transformers manufactured for domestic use and export with nominal system voltages from 0.66 kV to 750 kV inclusive, for use in alternating-current networks of 50 or 60 Hz. It is intended for transformers that transmit measurement and protection signals to metering instruments, protection and control devices. The standard explicitly excludes laboratory/reference transformers, zero-sequence, summing, blocking and saturable (magnetic-core saturation) special-purpose transformers.

Key topics and requirements

• Classification of current transformers by installation environment and purpose (outdoor, indoor, underground, built into equipment housings) and by design parameters.
• Primary and secondary nominal parameters and accuracy classes (specifying limits of error for metering and protection classes such as 0.5, 1, 5P, 10P).
• Insulation requirements and coordination with voltage-level standards (requirements vary by nominal voltage up to 750 kV).
• Technical and safety requirements covering mechanical construction, dielectric strength, creepage/clearance, temperature rise and protective measures.
• Test methods and acceptance criteria, including routine and type tests (electrical, thermal, mechanical), and recommended partial-discharge measurement norms and test procedures (appendix).
• Requirements for marking, documentation, transport, storage and operational instructions supplied by the manufacturer.
• Normative references to related GOSTs and international standards (examples include IEC/МЭК references listed in the standard).

Typical use and users

This standard is used by current-transformer manufacturers, electrical equipment designers, utility engineering departments, instrument and protection equipment manufacturers, test laboratories, procurement/specification authors and conformity assessment bodies. It is referenced when specifying CT performance for metering, relay protection and control across transmission and distribution systems.

Related standards

Key related and referenced documents include the earlier ГОСТ 7746-78 (the 1978 edition replaced by 7746-89), the later ГОСТ 7746-2001 (which superseded the 1989 edition), and other normative references found in the text such as ГОСТ 15150 (environmental categories), ГОСТ 1516.1 (insulation requirements), and international IEC/МЭК standards cited in the foreword (e.g., IEC documents referenced by the original standard).

Keywords

current transformer; CT; measurement transformer; accuracy class; insulation; partial discharge; test methods; metering; protection; GOST 7746-89; transformer specifications.

FAQ

Q: What is this standard?

A: GOST 7746-89 is a Soviet-era national/interstate standard titled "Current transformers. General specifications" that sets general technical requirements and test methods for electromagnetic current transformers.

Q: What does it cover?

A: It covers classification, nominal parameters, accuracy classes, insulation and safety requirements, routine and type tests (including partial-discharge guidance), acceptance rules, transport/storage and manufacturer documentation for CTs rated from 0.66 kV to 750 kV, used with 50/60 Hz systems. It excludes laboratory/reference, zero-sequence, summing, blocking and saturable special-purpose transformers.

Q: Who typically uses it?

A: Manufacturers of current transformers, utility engineers, protection and metering equipment designers, testing laboratories and procurement/specification teams reference this standard when specifying or verifying CT performance.

Q: Is it current or superseded?

A: GOST 7746-89 is superseded — the later edition GOST 7746-2001 replaced it, and the 2001 version was adopted as the national standard of the Russian Federation effective 1 January 2003. Therefore the 1989 edition is not the current active standard for Russian practice.

Q: Is it part of a series?

A: Yes — GOST 7746 belongs to a family of standards for measurement and power equipment (group E64) and the document references and aligns with related national GOSTs and international IEC/МЭК standards applicable to transformers and electrical equipment. The 1989 edition itself replaced the 1978 edition and was later replaced by the 2001 edition.

Q: What are the key keywords?

A: Current transformer; CT; measurement transformer; accuracy class; dielectric/insulation; partial-discharge; test methods; metering; protection; GOST 7746-89.