Modular 2 way switch, 20A 240 V AC, 1 module — ISI-marked to IS 3854, with three terminals; for heavy loads switched from two places.
- Rated 20A, 240 V AC, as marked on the switch body.
- ISI-marked, made to IS 3854, the Indian standard for household switches.
- Three terminals — one common and two travellers — for two-way wiring.
- "20A" and up/down arrows printed on the rocker.
- Use a pair to switch one heavy load, or a light, from two places.
- Also works as a 20A 1 way switch, using the common and one other terminal.
- One module wide — clips into the base of a modular cover plate.
A 2 way switch connects its common terminal to one of two other terminals. Two of them, joined by two traveller wires, switch the same load from either end — the standard staircase and corridor arrangement. This 20A version does the same for heavier circuits, and it can also send one supply to either of two loads when only one of them should run at a time.
It is one module wide and clips into a modular cover plate and base on a concealed or surface box. For ordinary staircase and corridor lights, the 10A 2 way switch is enough.
How two-way wiring works
- The phase goes to the common terminal of the first switch.
- Two traveller wires join the other two terminals of the two switches.
- The common terminal of the second switch goes to the light or load.
- The neutral goes straight to the light or load and never passes through the switches.
For a heavy load, the traveller wires must be the same size as the rest of that circuit — typically 2.5 sq mm or more, as your electrician specifies.
Where to use it
- Two-way switching of heavy loads and power circuits.
- Sending one supply to either of two loads, when only one should run at a time.
- Staircases, corridors and halls with heavy lighting loads in shops, godowns and workshops.
How to install
- Switch off the supply at the MCB and check that the wires are dead.
- Connect the incoming phase to the common terminal, and the two travellers (or the two loads) to the other two terminals.
- Tighten the terminal screws firmly on the cable size your electrician has chosen.
- Clip the switch into the plate base, fit the plate and test from each switching point.
Electrical work should be done by a licensed electrician with the supply switched off. A 2 way switch breaks the phase only — it is not a mains/inverter or generator changeover switch.
Frequently asked questions
- When do I need a 20A 2 way switch instead of 10A?
- When the load on the two-way circuit is heavy — typically above 10A, such as a geyser, a power socket or a large lighting load. For normal staircase and corridor lights, 10A is enough.
- Can it be used as a 1 way switch?
- Yes. Use the common terminal and one of the other two terminals, and leave the third unused.
- Can it switch between two loads?
- Yes. Feed the phase to the common terminal and connect one load to each of the other two terminals. Only one load runs at a time.
- Can I use it as a mains and inverter changeover?
- It is not recommended. A 2 way switch changes over the phase only, so the neutrals stay joined. For an inverter or generator, use a proper changeover switch that switches both lines, fitted by an electrician.
- Which plate and box does a modular switch need?
- A modular cover plate with base (frame) and a box of the same module size — a concealed GI box inside the wall, or a surface gang box on the wall. The switch clips into the base and the plate covers the board. Count one module for each 1 module switch, and usually two for each socket or fan regulator.
Buy 20A modular 2 way switches online from Electric Market, Chennai. For site, contractor or bulk quantities, contact us for a quote.