Extra-low voltage lighting
Lighting that runs at no more than 50 V or 120 V , usually from a or electronic convertor. BS 7671's Section 715 covers it. The low cuts the shock risk but not the fire risk: 36 W draws about 0.16 A at 230 V but 3 A at 12 V, so a loose joint on the low-voltage side can get hot enough to start a fire.
Using Extra-low voltage lighting in context
Reviewed
A distinction worth remembering
In an ideal resistive example, increasing resistance at a fixed voltage reduces current. Raising voltage across the same resistance increases current. State the fixed quantity first: this avoids treating a formula triangle as a model for every kind of load.
Questions to take further
- How can I revise Extra-low voltage lighting beyond the definition?
- Explain what Extra-low voltage lighting describes, compare it with a related term and use it in a topic question. State any assumptions and what evidence you would need before applying the idea to real work.
Sources
- Open University: relationships between electrical quantities — The relationship between voltage, current and resistance and the limits of an ohmic model.
Where Extra-low voltage lighting fits in the learning path
The Special Locations section covers these units:
- Wet locations
- Sites, farms and shows
- Moving and temporary
- Heating, lighting and the outdoors
Curriculum mapping: C&G 2382-26 (BS 7671 Part 7).
See this section in the full curriculum
This section is on the Plus path. Lesson availability depends on content review and your learning path.
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- Ohm's LawElectrical Science
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- Electrical Science — quiz previewFree · Electrical Science
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Recall a related term
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An extra-low-voltage protective arrangement using a suitable source, such as a safety isolating transformer, with protective separation from higher-voltage circuits and no intentional connection to Earth. The complete source and circuit must meet the arrangement's requirements; a low voltage label alone is not enough. A conventional transformer-fed shaver supply uses electrical separation and is not automatically SELV.
Compare related terms
Open a meaning to compare its role with Extra-low voltage lighting, or follow its full entry.
SELV — Separated Extra-Low Voltage
An extra-low-voltage protective arrangement using a suitable source, such as a safety isolating transformer, with protective separation from higher-voltage circuits and no intentional connection to Earth. The complete source and circuit must meet the arrangement's requirements; a low voltage label alone is not enough. A conventional transformer-fed shaver supply uses electrical separation and is not automatically SELV.
Read the SELV entryTransformer
A device that transfers electrical energy between windings through a changing magnetic field. It can raise or lower AC voltage according to the winding arrangement, with losses meaning output power is below input power. A site centre-tapped transformer also changes how its output is referenced to earth.
Read the Transformer entrySpecial location
A place or type of installation where the risks are higher or different, so BS 7671's Part 7 adds to or changes its general rules. Bathrooms, swimming pools, construction sites, caravan parks and EV charging all have their own section there. Read that section before designing or testing, because the general parts still apply unless it changes them.
Read the Special location entryA definition is a start. Using it in a real question is where it sticks.