EM-M
Maintained emergency luminaire plan mark
Plan mark for an emergency luminaire whose lamp is lit at all times and stays lit on supply failure.
IEC
Functional block · SMCI
Switchroom maintained-lighting control interface
Functional block · Switchrooms
An independently authored application reference. The drawing shows the named function or circuit relationship; use the project legend and selected equipment documentation for its drafting form and connections.
Browse this installation focusIn plain English
What this block does
Separates the normal operating command from the emergency supply behavior of maintained lighting.
A simple example
In a switchroom, a normal lighting branch may be switched locally while the specified emergency luminaires remain connected to their own backed-up or integral supply. For this reference, the drawing identifies “Normal lighting control” at the input and “Maintained luminaire interface” at the output. The exact wiring follows the selected fitting.
What the drawings help you do
Start at the named input: Normal lighting control. Identify its source device or document and the state represented on the drawing. Follow the named output: Maintained luminaire interface. Cross-reference its destination and separate the command from confirmation that the equipment responded.
- Input
- Normal lighting control
- Output
- Maintained luminaire interface
- Application reference
- An explanation of a named drawing function or circuit relationship; the project documents define the equipment and its connections.
Read the source: Indoor substation: lighting, fire and auxiliary services
Schematic · SMCI
What it represents
Separates the normal operating command from the emergency supply behavior of maintained lighting. 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.
In a switchroom, a normal lighting branch may be switched locally while the specified emergency luminaires remain connected to their own backed-up or integral supply. For this reference, the drawing identifies “Normal lighting control” at the input and “Maintained luminaire interface” at the output. The exact wiring follows the selected fitting.
Identify the lighting supply type, controlled circuit and the meaning of any test or failure output. A drawing symbol does not establish illumination levels, emergency duration or an approved egress arrangement. The functional block is an independent explanation of this named application. Equipment-specific ratings, terminal connections and operating conditions must be established in the project documentation.
How to read it
- Start at the named input: Normal lighting control. Identify its source device or document and the state represented on the drawing.
- Follow the named output: Maintained luminaire interface. Cross-reference its destination and separate the command from confirmation that the equipment responded.
- The exact wiring follows the selected fitting.
- Identify the lighting supply type, controlled circuit and the meaning of any test or failure output. A drawing symbol does not establish illumination levels, emergency duration or an approved egress arrangement.
Information to show or reference
- Label the source and connection reference for normal lighting control.
- Identify the destination and defined state of maintained luminaire interface.
- Record the equipment or control-document revision supporting this functional block.
- Check this application limit in the project design: The exact wiring follows the selected fitting.
A distinction that matters
The exact wiring follows the selected fitting. 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.
Sources you can follow
These public references support the explanation and provide further detail. Their graphics and downloadable files remain with their publishers.
Indoor substation: lighting, fire and auxiliary services
Public technical context for switchroom lighting and access interfaces. Lighting, emergency lighting, fire provisions and substation auxiliary services. Original cause-and-effect examples require project design. The application text and educational graphic are independently authored; the publisher does not certify this representation.
About this graphic
This illustration was authored independently by Elora Grid to explain the concept. It is not reproduced from a customer drawing, an official standard graphic or a manufacturer CAD file. Its correspondence to an exact IEC or IEEE symbol identifier has not been certified.
SVG and DXF downloads contain this original artwork. Original artwork is available under CC BY 4.0. Third-party references retain their own terms.
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