【Safety Certification】Definition of PELV Circuit & SELV Circuit in IEC/EN/UL 61800-5-1

Do you know the definition of protective ELV (PELV) circuit and Safety ELV (SELV) circuit in IEC/EN/UL 61800-5-1?
 

• Protective ELV (PELV) Circuit

electrical circuit with the following characteristics:
- the voltage does not continuously exceed ELV under single fault as well as normal conditions;
- protective separation from circuits other than PELV or SELV;
- provisions for earthing of the PELV circuit, or its accessible conductive parts, or both.
 

• Safety ELV (SELV) Circuit

electrical circuit with the following characteristics:
- the voltage does not exceed ELV;
- protective separation from circuits other than SELV or PELV;
- no provisions for earthing of the SELV circuit, or its accessible conductive parts;
- basic insulation of the SELV circuit from earth and from PELV circuits.
 
[Note]
- IEC/ EN/ UL 61800-5-1:
Adjustable Speed Electrical Power Drive Systems – Part 5-1,
Safety Requirements – Electrical, Thermal and Energy
 
- Extra Low Voltage (ELV)
any voltage not exceeding 50 V ac r.m.s. and 120 V dc.
 
GCS Safety Team