What is a SELV circuit?

Separated Extra Low Voltage (SELV) system is an extra low voltage electrical circuit that is electrically separated from other circuits that carry higher voltages, isolated from the earth and from the protective earth conductors of other circuits.

What does SELV mean in electrical?

Safety Extra Low Voltage
SELV (Safety Extra Low Voltage) describes a voltage that is set so low that in the event of direct touch either during proper operation or in the event of a single fault there is no danger of electric shock due to touch current. In the event of an insulation failure, adequate protection must still be provided.

Where are SELV circuits used?

The SELV systems are used in applications where operating some electrical appliances poses a serious safety hazard. Typical locations include amusement parks, swimming pools as well as some domestic electrical appliances such as radios.

What is classed as SELV?

IEC defines a SELV system as “an electrical system in which the voltage cannot exceed ELV under normal conditions, and under single-fault conditions, including earth faults in other circuits”.

What is a SELV or PELV power supply?

SELV and PELV systems are designed to eliminate the risk of electric shock. SELVs are electrical systems separated from ground and other nearby systems — so voltage is incapable of exceeding ELV during normal and even single-fault conditions. The latter includes nearby systems’ earth faults during system separation.

What is SELV output?

SELV stands for Safety Extra Low Voltage. Some AC-DC power supply installation manuals contain warnings concerning SELV. For example, there may be a warning about connecting two outputs in series because the resulting higher voltage may exceed the defined SELV safe level, which is less than or equal to 60VDC.

What does PELV mean?

Protective Extra-Low Voltage
An electric system in which the voltage cannot exceed the value of extra-low voltage under normal conditions and under single fault conditions, except earth faults in other circuits.

What is an example of PELV?

An example of a SELV or PELV circuit is an extra-low voltage circuit fed by a safety isolating transformer and supplying luminaires.

What are PELV circuits?

PELV (Protective Extra Low Voltage, formerly known as extra low voltage) describes a voltage that is set so low that in the event of indirect contact and small area direct contact there is no risk of electric shock.