Glossary.
- 230 V, 50 Hz
- The standard single-phase mains supply in India.
- Air delivery (CMM)
- How much air a fan moves, in cubic metres per minute.Guide →
- B22
- The 22 mm bayonet lamp cap used in most Indian household holders.Guide →
- BEE star rating
- The Bureau of Energy Efficiency's star label for appliances in India. More stars mean more efficient.
- BLDC motor
- Brushless DC motor: an electronically controlled motor used in energy-efficient fans.Guide →
- Breaking capacity (kA)
- The largest fault current a breaker can safely interrupt, such as 6 kA or 10 kA.
- COB LED
- Chip-on-board: many LED chips packaged as one small emitting surface, giving a focused beam.Guide →
- Colour temperature (CCT)
- The colour of white light in kelvin (K): about 2700–3000K is warm, 4000K neutral, 5700–6500K cool daylight.Guide →
- Conduit
- The pipe that protects and routes wires inside walls, ceilings and slabs.Guide →
- CRI (colour rendering index)
- How accurately a light shows colours compared with daylight, on a 0–100 scale. 80+ is good for general use; 90+ where colour matters.
- Diffuser
- The opal or frosted cover that spreads light evenly and hides individual LEDs.
- DIN rail
- The standard 35 mm metal rail that MCBs, RCCBs and other modular devices clip onto.
- Distribution board (DB) / MCB box
- The enclosure that holds the main switch, RCCB and MCBs for a building's circuits.
- E27
- The 27 mm Edison screw lamp cap used in many decorative and imported fittings.Guide →
- Earthingअर्थिंग
- Connecting metal parts of an installation to the ground so fault current flows safely and protective devices trip.
- Efficacy (lm/W)
- Lumens per watt — how efficiently a light turns electricity into light.
- ELCB
- Earth leakage circuit breaker — an older term. Devices sold as ELCBs today are usually RCCBs.Guide →
- FR / FR-LSH
- Flame retardant / flame retardant, low smoke and halogen — insulation grades for house wires.Guide →
- Gang box
- The box set into the wall behind a modular switch plate.Guide →
- IP rating
- Ingress Protection rating (IEC 60529): first digit for dust and solids, second for water.Guide →
- Isolator
- A manually operated switch for safely disconnecting a supply. It gives no automatic protection.
- LED driver
- The electronic circuit that converts 230 V AC mains into the steady DC that LEDs need.
- Lumen (lm)
- The total amount of visible light a source gives out. Use it to compare LED products instead of watts.Guide →
- Lux (lx)
- The amount of light falling on a surface: one lumen per square metre. Room lighting targets are given in lux.Guide →
- MCBमिनिएचर सर्किट ब्रेकर
- Miniature circuit breaker: switches a circuit off automatically on overload or short circuit.Guide →
- Module (M)
- The unit width of modular switches and plates; a switch is usually 1M, a socket 2M.Guide →
- Phase, neutral, earthफ़ेज़, न्यूट्रल, अर्थ
- The three conductors in single-phase wiring: phase carries current to the load, neutral returns it, earth carries fault current safely to ground.Guide →
- RCBO
- A single device combining MCB (overload and short circuit) and RCCB (earth leakage) protection.Guide →
- RCCBआरसीसीबी
- Residual current circuit breaker: trips when current leaks to earth, protecting people from shock. Often called an ELCB.Guide →
- Service value
- A fan's air delivery divided by its power (CMM/W) — a measure of efficiency.Guide →
- SMD LED
- Surface-mounted LED packages spread across a board for wide, even light.Guide →
- Space factor
- The share of a conduit's internal area taken up by cables — keep it to about 40%.Guide →
- sq mm
- Square millimetres: the cross-sectional area of a wire's copper conductor, which sets how much current it can carry.Guide →
- Sweep
- The diameter of the circle a ceiling fan's blades cover, e.g. 1200 mm (48 inch).Guide →
- Tripping curve (B, C, D)
- How quickly an MCB trips on a surge: B at 3–5×, C at 5–10×, D at 10–20× its rated current.Guide →