Understand the difference.

Compare the meaning, drawing context and source references of two entries. A similar graphic or shared abbreviation does not establish equivalence.

SOI

IEC

Socket outlet with interlocked switch

Interlocked socket outlets are used for industrial plugs, welding outlets, portable plant supplies and higher-current three-phase outlets. The interlock forces the user to switch off before the plug can be removed or inserted, which prevents drawing an arc at the pins. The plan mark adds a switch stroke and a small interlock bar to the outlet form.

Drawing use

GA

Application

Installation & communications

Reference family

IEC

Form evidence

Socket outlet with interlocked switch. IEC 60617 installation-plan style (architectural and topographical installation symbols); independently drawn, not certified IEC geometry or a database identifier.

A distinction that matters

A simple switched outlet allows the plug to be withdrawn while energised; the interlocked form mechanically prevents it.

Full referenceAdd to legend

SSO

IEC

Switched socket outlet

A switched socket outlet combines the outlet and a single-pole or double-pole switch in one accessory plate. On the plan the outlet half circle carries a short switch stroke with a tick, borrowed from the light-switch form, showing that the user can interrupt supply at the outlet without removing the plug.

Drawing use

GA

Application

Installation & communications

Reference family

IEC

Form evidence

Switched socket outlet. IEC 60617 installation-plan style (architectural and topographical installation symbols); independently drawn, not certified IEC geometry or a database identifier.

A distinction that matters

A socket outlet with interlocked switch prevents plug insertion or withdrawal while energised; a plain switched outlet only lets the user switch the supply.

Full referenceAdd to legend

Original educational previews. Follow the source references on each full entry for the appropriate standard or selected product.