Standard No.:	GB/T 1094.3-2017
Chinese Name:	电力变压器 第3部分：绝缘水平、绝缘试验和外绝缘空气间隙
English Name:	Power transformers—Part 3:Insulation levels,dielectric tests and external clearances in air
Professional Classification:	K41 Transformer
ICS Classification:	29.180
Issued by:
Issued on:	2017-12-29
Implemented on:	2018-07-01
Status:	VALID
Replace:	GB/T1094.3-2003
Language:	English
File Format:	PDF
Word Count:	28000 words
Price(USD):	840 (USD)
Delivery:	via email in 1-8 business day

1 Scope

This part of GB/T 1094 specifies the applicable dielectric tests and minimum dielectric test levels for power transformers. Recommended minimum external clearances in air between live parts and between live parts and earth are given for use when these clearances are not specified by the purchaser.
This part applies to power transformers as defined by and in the scope of GB/T 1094.1. For categories of power transformers and reactors which have their own standards, this part is applicable only to the extent in which it is specifically called up by cross reference in the other standards.

2 Normative References

The following referenced documents are indispensable for the application of this document. For dated references, only the edition cited applies. For undated references, the latest edition of the referenced document (including any amendments) applies.
GB/T 311.1 Insulation Coordination—Part 1: Definitions, Principles and Rules (GB/T 311.1-2012, IEC 60071-1:2006, MOD)
GB/T 1094.1 Power Transformers—Part 1: General (GB/T 1094.1-2013, IEC 60076-1:2011, MOD)
GB/T 2900.95 Electrotechnical Terminology—Transformers, Voltage Regulators and Reactors (GB/T 2900.95-2015, IEC 60050-421:1990, NEQ)
GB/T 4109 Insulated Bushings for Alternating Voltages above 1 000V (GB/T 4109—2008, IEC 60137 Ed.6.0, MOD)
GB/T 7354 Partial Discharge Measurements(GB/T 7354—2003, IEC 60270:2000, IDT)
GB/T 16927.1-2011 High-voltage Test Techniques—Part 1: General Definitions and Test Requirements (IEC 60060-1:2010, MOD)
GB/T 16927.2 High-voltage Test Techniques—Part 2: Measuring Systems (GB/T 16927.2-2013, IEC 60060-2:2010, MOD)

3 Terms and Definitions

For the purposes of this document, the terms and definitions given in GB/T 1094.1, GB/T 2900.95 and the following apply.
3.1
highest voltage for equipment applicable to a transformer winding
Um
highest r.m.s. phase-to-phase voltage in a three-phase system for which a transformer winding is designed in respect of its insulation