Cam operated rotary switch with OFF, 1, 2 and 3 positions, 32A to 63A — for phase selection and panel switching; the 40A is rated AC-23A at 415 V.
- Four positions — OFF, 1, 2 and 3 — marked on the front plate.
- Cam-operated contact block behind a square front plate, turned by a large grip handle.
- The 40A switch pictured is marked IEC 60947-3, AC-23A at 415 V, 50 Hz.
- Its label recommends a 40A back-up fuse.
- Terminals marked A1, A2 and A3, plus a common terminal, on the 40A unit.
- Made for panel mounting: plate and handle in front, contacts behind.
- A switch, not a breaker — protect the circuit with a fuse or MCB.
A cam operated rotary switch turns a handle through fixed positions; cams on the shaft open and close sets of contacts in each position. This one has four positions — OFF, 1, 2 and 3 — so a circuit can be switched off or connected through any one of three positions.
The unit pictured has terminals marked A1, A2 and A3 — a layout commonly used as a phase selector, feeding a single-phase load from any one of the three phases (R, Y or B), or to connect one supply to one of three circuits. Check the terminal diagram before wiring.
Ratings in this listing: 32A, 40A and 63A. Choose one at or above the load current and the fuse or MCB that protects the circuit; the 40A unit is marked AC-23A, the IEC 60947-3 duty for switching motors and other inductive loads.
Where to use it
- Phase selector for single-phase loads on a three-phase supply.
- Selecting one of three circuits, pumps or machines from one supply.
- Control panels, pump panels and machine panels.
- Workshops, small factories and commercial buildings.
How to install
- Switch off and isolate the supply before working.
- Cut the panel opening, fit the switch body behind the panel and the front plate and handle in front.
- Wire the common terminal and A1, A2, A3 as the terminal diagram shows — for phase selection, the three phases to A1, A2, A3 and the load to the common terminal.
- Protect the circuit with a fuse or MCB of suitable rating, then check every position before connecting the load.
Electrical work should be done by a licensed electrician. Switch heavy loads off before changing phase or circuit.
Frequently asked questions
- What is a cam operated rotary switch?
- A switch with a turning handle: cams on the shaft open and close contacts in each position. It is used on panels to select phases, circuits or operating modes.
- What do OFF, 1, 2 and 3 mean?
- OFF disconnects the circuit; 1, 2 and 3 each connect it through a different contact set (terminals A1, A2 and A3 on the unit pictured). As a phase selector, each position picks one phase — R, Y or B — for the load.
- What does AC-23A mean?
- AC-23A is the IEC 60947-3 utilisation category for frequently switching motor loads and other highly inductive loads — a demanding duty. The 40A switch pictured is marked AC-23A at 415 V.
- Does it protect the circuit?
- No. It is a switch only. Use a fuse or MCB of suitable rating ahead of it — the 40A unit label recommends a 40A back-up fuse.
- Which rating do I need?
- One at or above the current the load draws and the fuse or MCB that protects the circuit: 32A, 40A or 63A.
Buy cam operated rotary switches online from Electric Market, Chennai. For panel builders, contractors and bulk orders, contact us for a quote.