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

SLRI

Symbols

Switchroom lighting-contact relay interface

Links the lighting-control relay to the power contacts serving the selected branch. Lighting and access interfaces coordinate the electrical-room service circuits and their supervision. Normal lighting, emergency illumination and access indication have different power sources and purposes.

Drawing use: Schematic
Application: Installation & communications
Reference family: Manufacturer

A distinction that matters

Contact rating depends on the actual lighting load. This reference describes the named application; it does not establish a new IEC graphical symbol, an ANSI device-function number or an exact manufacturer connection diagram.

Full reference

EM-M

IEC

Maintained emergency luminaire plan mark

A maintained emergency luminaire operates as a normal light and continues on battery when the normal supply fails. Plans usually draw the luminaire mark with an emergency indicator, such as a filled segment or a letter E, plus an M or maintained tag.

Drawing use: GA
Application: Installation & communications
Reference family: IEC
Form evidence: Emergency luminaire, maintained. 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 non-maintained emergency luminaire lights only on supply failure; the maintained form is lit continuously.

Full reference

Follow the full entry for source drawings and the appropriate standard or selected product. Equipment previews show a manufacturer drawing where available, otherwise a 3D thumbnail.