1 Way or 2 Way Switch? How Each Works and Where It Goes
The difference between a 1 way and a 2 way switch is how many places can control the light. A 1 way switch turns a light on and off from one place. A pair of 2 way switches controls the same light from two places, such as the top and bottom of a staircase. Below: how each works, where to fit them, what “2 gang” means, and what they cost in our KEMPS, VIZA and VIYONA ranges.
Key takeaways
- 1 way switch — two terminals; controls a light from one place. Most switches in a home.
- 2 way switch — three terminals; two of them control one light from two places.
- Where 2 way belongs — staircases, long corridors, and a bedroom light switched at the door and the bed.
- A 2 way switch can work as a 1 way, so some electricians stock only 2 way. It costs a little more.
- ⚠ Wiring a 2 way circuit means running extra wires between the two switches. That is a licensed electrician’s job.
1 way vs 2 way switch: the short answer
A 1 way switch has two terminals and one job: it connects or breaks the live wire to a light or appliance, from one place. Almost every switch in a home is a 1 way switch.
A 2 way switch has three terminals: a common terminal and two others, often marked L1 and L2. Its lever connects the common terminal to one or the other. Fit two of them, connected to each other by two wires, and either switch can turn the same light on or off. That is how a staircase light is controlled from both floors.
We make both types in 10A and 20A ratings across our KEMPS and VIZA modular ranges, and in our VIYONA conventional range. The difference in price is small; the difference in wiring is what matters.
How a 2 way switch works
Picture two switches, A and B, one at each end of a staircase. The live wire goes to the common terminal of switch A. Two wires, often called travellers, run from A’s L1 and L2 to B’s L1 and L2. The common terminal of switch B goes to the light.
The light is on when both switches point to the same traveller, and off when they point to different ones. Flip either switch and the state changes. That is the whole trick, and it is why a 2 way circuit needs extra wires between the two switch positions.
This is an explanation, not wiring instructions. A 2 way circuit has live conductors at both switch positions; have it wired and tested by a licensed electrician.
| 1 way switch | 2 way switch | |
|---|---|---|
| Terminals | 2 | 3 (common, L1, L2) |
| Controls a light from | One place | Two places (as a pair) |
| Typical use | Most lights, fans, sockets | Stairs, corridors, bedroom door and bed |
| Can replace the other | No | Yes, wired as a 1 way |
| KEMPS 10AX MRP | ₹65 (K101) | ₹105 (K102) |
| VIYONA 16A MRP | ₹74 (151) | ₹90 (152) |
Where to use a 1 way and a 2 way switch
Use a 1 way switch wherever a light or appliance is controlled from a single place: most room lights, fans, a geyser, a socket. Use 2 way switches wherever you would otherwise walk in the dark to reach the switch.
Where 2 way switches are commonly fitted
Common practice. Decide the positions before the walls are closed; adding a 2 way later means running new wires.
One switch, one place, two terminals.
A pair controls one light from two places.
Where 2 way switches earn their cost.
A 2 gang unit has two switches in one module.
Can a 2 way switch be used as a 1 way switch?
Yes. Connect the common terminal and one of the other two, and leave the third unused. The switch then works exactly like a 1 way switch. Some electricians stock only 2 way switches for this reason.
The trade-off is cost. A 2 way switch costs more than a 1 way of the same range: in our KEMPS range the K101 10AX 1 way is ₹65 in white and the K102 10AX 2 way is ₹105. Across a whole house, fitting 2 way everywhere adds up.
Label the unused terminal or note it for the next electrician. A 2 way switch wired as a 1 way looks confusing when someone opens the board later.
What does 2 gang 1 way or 2 way mean?
Gang is the number of switches in one unit. A 2 gang switch has two levers, each controlling its own circuit. So a 2 gang 1 way switch controls two lights from one place, and a 2 gang 2 way switch has two 2 way levers.
Our KEMPS range makes this concrete: the K171 is a 2M module with two 10AX 1 way switches (₹140), the K172 two 10AX 2 way switches (₹268), and the K173 one 1 way plus one 2 way (₹209).
What about controlling a light from three places?
Three or more switch positions need an intermediate switch fitted between the two 2 way switches. It swaps the two traveller wires, so any of the three switches can change the state of the light.
We do not make an intermediate switch, and we would rather say so than leave you to find out at the counter. For most homes, a pair of 2 way switches covers every staircase and corridor.
1 way vs 2 way switch price
A 2 way switch typically costs ₹15–₹40 more than the 1 way in the same range. From our current catalogue:
MRP: 1 way vs 2 way in the same range (white)
MRPs as printed in our current catalogue, 1 way / 2 way. Bar length follows the 2 way price.
Product pages with photos: KEMPS K102 10AX 2 way, KEMPS K142 10AX 2 way and KEMPS K107 20AX 2 way.
Planning 2 way switches before the walls are closed
The cheapest time to add a 2 way switch is before plastering. The two traveller wires between the switch positions run through conduit in the wall; adding them after the walls are finished means chasing new channels or running surface conduit. Walk through the house with the electrician and decide every place you would want to switch a light from.
Three places are commonly forgotten: the bedroom light at the bed, the passage light at both ends, and the terrace or balcony light at both the door and the far end. Each needs a 2 way switch at both positions, so count them in pairs when you order.
On a modular board, a 2 way switch takes the same 1M space as a 1 way, so it changes nothing about the plate size. Our plate size calculator works out the plate for the mix of switches on each board.
Order 2 way switches in pairs, one for each end, and in the same range as the rest of the board so the modules fit the same frames.
10A or 20A: which rating for a 2 way switch?
Match the rating to the load, exactly as for a 1 way switch. Lights and fans are typically on 10A switches. A 2 way switch controlling a heavier load needs 20A. Our switch and socket ratings table lists every rating we make, and types of electrical switches covers bell pushes, indicators and DP switches.
Replacing a 2 way switch? Buy the same rating and module size from the same range, and note which wire is on the common terminal before you disconnect anything. See how to replace a switch safely.
FAQs
What is the difference between a 1 way and a 2 way switch?
Where is a 2 way switch used?
Can I use a 2 way switch as a 1 way switch?
What is a 2 gang 1 way 2 way switch?
How do I control a light from three places?
How much more does a 2 way switch cost?
Why buyers choose Vinayak Electricals
- Modular (KEMPS, VIZA) and conventional (VIYONA) switches, both made in-house in Mumbai.
- Switches made to IS 3854 under ISI licence CM/L-7567794.
- MRPs published openly in our catalogue, code by code.
- Plates from 1M to 18M in white, metallic, wood, glass and acrylic finishes.
- Sold through dealers across India; dealers can order from us directly.
- Over 30 years manufacturing electrical goods; ISO 9001:2015 certified.
Find the 2 way switch for your range
KEMPS modular switches with codes, ratings and MRPs.
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