Electrical breakdown

Example

Use in Lemonergy

Relate protection to faults, detection and response.

This is a reference concept. No executable Lemonergy block has been verified for this term.

Connected concepts

Related concepts from the knowledge graph. Connections show context, not cause and effect. Hover or focus a linked term for its definition.

Arcing

Current continuing through ionised gas across a gap, typically between contacts as they separate. An AC arc goes out by itself at each current zero, a hundred times a second at 50 Hz; a DC arc has no zero and keeps burning until it is stretched and cooled so far that its voltage exceeds the source’s, which makes high-voltage DC far harder to interrupt.

Clearance

The shortest distance through air between two conductive parts at different potentials. It is sized for the highest transient voltage the insulation must withstand, since air breaks down at roughly 3 kV/mm, and must grow above 2000 m altitude where thinner air breaks down sooner. IEC 60664-1 sets the values for most electronics.

Creepage distance

The shortest path between two conductors measured along the surface of the insulation between them. Moisture and dirt on that surface can carry leakage current and tracking, so the required distance grows with working voltage, pollution and a poorer tracking index: at 400 V and pollution degree 2, basic insulation needs about 2 mm on a group I material but 4 mm on group III.

Insulation resistance

The resistance between the high-voltage circuit and the vehicle chassis, which must stay above about 100 Ω per volt of pack voltage so a person touching the chassis is safe. An insulation monitoring device measures it continuously.

Insulation resistance test

Applying a high DC or AC voltage between the high-voltage circuit and the chassis or housing to verify that insulation holds, with the leakage current below a limit. It is done on every pack at end of line and after abuse tests in R100.

References & further reading

Further reading on this topic

These sources provide broader context; they are not presented as citations for every statement in this entry.

1. ISO 26262-1:2018 — Road vehicles — Functional safety — Part 1: Vocabulary

   International Organization for Standardization · 2018

   Topic background · Scope and terminology of automotive electrical/electronic functional safety. The catalogue is not the full standard.