Side-by-side reference

Understand the difference.

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

First referenceCompare with

SPL

IEC

Switch with pilot light plan mark

A switch with pilot light is used where the controlled load cannot be seen from the switch position, such as an external light, a water heater or a loft. The plan form adds a small lamp mark, a crossed circle, to the switch symbol.

Drawing use: GA
Application: Installation & communications
Reference family: IEC
Form evidence: Switch with pilot lamp. 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 plain one-way switch has no lamp; this form adds visual confirmation of the load state.

Full reference

IEC

One-way light switch plan mark

The one-way switch is drawn on IEC-style plans as a small circle at the switch position with a short stroke ending in one tick. A dashed or curved switching line usually runs from the symbol to the luminaires it controls, telling the electrician which lights are switched together.

Drawing use: GA
Application: Installation & communications
Reference family: IEC
Form evidence: One-way switch, single pole. 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 two-way switch has a second stroke so it can be paired with another switch; the one-way form controls from one point only.

Full reference

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