GOST 7746-2015 PDF

Full title and description

GOST 7746-2015 — "Current transformers. General specifications" (Russian: ГОСТ 7746-2015, Трансформаторы тока. Общие технические условия). The standard sets general technical requirements for electromagnetic current transformers intended to supply measurement, protection, automation, signalling and control devices in AC networks.

Abstract

This standard establishes terms and definitions, ratings and constructional requirements, accuracy classes and conditions, insulation and thermal limits, mechanical strength, testing (type, routine and special tests), marking, documentation, storage and transport requirements for electromagnetic current transformers rated for use in AC systems. It aligns national requirements with international instrument-transformer practice (references to IEC 61869 series) and replaces the earlier GOST 7746-2001.

General information

• Status: Active / In force (replaces GOST 7746-2001).
• Publication date: Adopted in 2015 (standard designation year 2015); approved by the Federal Agency for Technical Regulation and Metrology on 23 June 2016 and published/entered into use in practice in 2017 (documents commonly list 01 March 2017 as a publication/registration date).
• Publisher: Federal Agency for Technical Regulation and Metrology (Rosstandart) / interstate standardization bodies (as a GOST).
• ICS / categories: 17.220.20 — Metrology and measurements; Electricity. Magnetism. Electrical and magnetic measurements. Measurement of electrical and magnetic quantities.
• Edition / version: GOST 7746-2015 (first edition under this designation; replaces GOST 7746-2001).
• Number of pages: Listed online as 43–44 pages depending on format/edition (sources commonly show 43 or 44 pages).

Scope

Applies to electromagnetic current transformers with nominal system voltages from 0.66 kV up to 750 kV inclusive, intended for transmission of measuring information to instruments for measurement, protection, automation, signalling and control in AC circuits at 50 or 60 Hz. The standard is written for transformers developed after 1 January 2016 and does not cover laboratory transformers, zero-sequence (residual) transformers, summing, blocking or saturating transformers; additional specific requirements for particular designs or purposes are to be set in technical specifications, contracts or product standards.

Key topics and requirements

• Terms, definitions and normative references (including alignment with IEC 61869 series — general requirements and current-transformer specific parts).
• Rated values and designation (nominal currents, voltages, frequency, rated burden and accuracy classes).
• Design and constructional requirements (insulation clearances, creepage distances, magnetic circuit, enclosure and hardware provisions for mounting and secondary terminals).
• Accuracy and performance requirements (accuracy classes, limits of permissible errors, behaviour under specified burdens and short-circuit conditions).
• Thermal and mechanical strength limits; allowable temperature rises and vibration / mechanical endurance considerations.
• Type, routine and special test methods, including accuracy tests, dielectric tests, temperature rise, short-circuit tests and mechanical tests.
• Marking, documentation, packaging, storage and transportation requirements.
• Safety, environmental and electromagnetic compatibility provisions as called out or by reference to other normative documents.

Typical use and users

Used by electrical equipment manufacturers (current-transformer makers), power utilities, protection and metering equipment designers, testing and calibration laboratories, procurement specialists preparing technical specifications and contract documents, and regulatory bodies setting conformity and safety requirements. It is referenced in contract specifications for substation and switchgear equipment where instrument transformers are supplied.

Related standards

References and related documents include the superseded GOST 7746-2001, national standards on terms and verification of current transformers (for example GOST 18685 series and GOST 8.217-2003), standards on degrees of protection (IP code) and various IEC instrument-transformer standards (notably IEC 61869-1 and IEC 61869-2 which are taken into account in this GOST). Additional related GOSTs address insulation testing, thermal limits and product documentation.

Keywords

current transformer; instrument transformer; accuracy class; rated burden; insulation; dielectric test; temperature rise; type tests; routine tests; marking; GOST 7746-2015; ГОСТ 7746-2015; IEC 61869.

FAQ

Q: What is this standard?

A: GOST 7746-2015 is the national (GOST) standard that defines general technical specifications for electromagnetic current transformers used in AC power systems for measurement, protection and control.

Q: What does it cover?

A: It covers ratings, constructional and performance requirements, accuracy and testing procedures, marking/documentation, and conditions for storage and transport for current transformers rated from 0.66 kV to 750 kV for 50/60 Hz systems. It excludes laboratory, zero-sequence, summing, blocking and saturating transformers.

Q: Who typically uses it?

A: Manufacturers, substation and switchgear equipment specifiers, power utilities, protection and metering engineers, testing/calibration laboratories and procurement/quality departments.

Q: Is it current or superseded?

A: GOST 7746-2015 is the current active standard (it replaces GOST 7746-2001). The document was adopted in 2015, approved by the Federal Agency for Technical Regulation and Metrology on 23 June 2016, and registered/put into use in practice thereafter (commonly referenced publication/registration date is 01 March 2017 in public listings).

Q: Is it part of a series?

A: It is the GOST-level general-specification for current transformers and is implemented alongside other standards in the instrument-transformer family; it also takes into account the IEC 61869-series (general requirements and current-transformer specific parts). Specific transformer types or applications may be covered by additional technical specifications, product standards or contractual requirements.

Q: What are the key keywords?

A: Current transformer; instrument transformer; accuracy class; rated burden; insulation; dielectric test; temperature rise; type and routine tests; marking; GOST 7746-2015; IEC 61869.