Battery knowledge · High-voltage and functional safety

Extra-low voltage

Voltage low enough to need reduced shock protection: at most 50 V AC rms or 120 V ripple-free DC under IEC 61140. SELV is separated from higher voltages and from earth; PELV is separated but earthed; FELV is low in value only, without protective separation, so it is protected like the circuit feeding it. Vehicle rules draw their line lower, at 60 V DC.

Abbreviation
ELV
Also called
SELV, PELV, FELV, safety extra-low voltage, protective extra-low voltage

Example

High-voltage and functional safety: an example situation

Normal-operation current limits do not demonstrate correct contactor behavior under a welded-contact or sensor fault.

Read Extra-low voltage alongside 48 V system in this context. A vehicle electrical architecture at 48 V, used for mild hybrids and heavy accessories. It stays below the 60 V threshold at which high-voltage safety rules begin, so it needs no orange cables or interlocks.

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.

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.