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IEC 60664-1:2020 / GB/T 16935.1-2008

Insulation coordination for equipment within low-voltage systems - Part 1: Principles, requirements and tests

📅 Issue date：2020 🔄 Effective date：2008 🌍 Type：国际标准 / 国家标准 等同采用

📑 Table of Contents

01 Scope

IEC 60664-1 specifies principles, clearance, creepage distances and solid-insulation requirements for insulation coordination of equipment in low-voltage systems (≤1000 V AC), preventing breakdown and long-term ageing.

02 Normative references

  1. IEC 60664-1:2020
  2. IEC 60664-3 Coating/potting (if applicable)

03 Terms and definitions

Clearance
Shortest distance in air between two conductive parts.
Creepage distance
Shortest path along insulating surface between two conductive parts.
Pollution degree
Level of conductive contamination (1~4).
Rated impulse withstand voltage
Impulse voltage the insulation can withstand.

04 Technical requirements

Coordination
Determine min. clearance & creepage from rated insulation voltage, overvoltage category and pollution degree.
Micro-environment
Pollution degree and material group (CTI) jointly set creepage.
Tests
Power-frequency and impulse withstand tests verify insulation.

05 Test methods

Withstand test
Apply rated impulse (1.2/50 μs) and power-frequency voltage; no breakdown/flashover.
Dimensional check
Measured clearance/creepage meet minimums for the rating.

📎 Related standards

GB 5226.1 Electrical safety IEC 61000-4-5 Surge
Disclaimer：This page is a technical summary of the corresponding standard for quick reference. All limits, clauses and methods are subject to the official publication and its latest amendments; formal compliance assessment must refer to the official issued text.