Off-load changeover switch with side handle, 32A to 200A at 415 V — selects mains or generator for a whole installation; operate it only with the load off.
- Selects which of two supplies feeds the installation — typically mains (EB) or a generator.
- Three handle positions: ON (supply 1), OFF in the centre, and ON (supply 2), as marked on the label.
- Off-load type: switch the load off first, then change over.
- 4 pole versions switch the three phases and the neutral; the 32A 2 pole version switches phase and neutral.
- Side handle outside the enclosure — change over without opening the door.
- White enclosure with a hinged door and grommeted cable entries at the top and bottom.
- No fuses and no trip — protect each supply with its own fuse unit, MCB or MCCB.
A changeover switch lets one installation run from either of two supplies, never from both at once. Moving the side handle from one ON position, through OFF, to the other disconnects the load from the first supply before connecting it to the second, so a generator can never feed back into the mains line.
This is an off-load switch: it is made to change over with no current flowing. Switch off the main breaker or the heavy loads downstream first, move the handle, then switch the load back on. It contains no fuses and does not trip, so each supply must be protected separately.
Which one do I need
- Single-phase supply up to 32A: 32A 2 pole.
- Three-phase + neutral supply: 4 pole, rated at or above the main fuse or breaker.
- 32A or 63A 4 pole: three-phase homes, shops and small offices.
- 100A or 200A 4 pole: larger buildings, workshops and factories.
Typical uses only — the rating must suit the supply, the generator and the cables.
Where to use it
- Mains and generator (DG set) changeover for homes, apartments and shops.
- Offices, hospitals, schools, hotels and factories with a standby generator.
- Choosing between two incoming supplies or feeders.
- Farm and pump-house supplies with a standby generator.
How to install
- Switch off and isolate both supplies before working.
- Fix the enclosure upright on a wall or panel, with room for the side handle to swing.
- Bring both supplies and the load in through the cable entries and connect them firmly to their marked terminals, on correctly sized cable.
- Protect each supply with its own fuse unit, MCB or MCCB, and earth the enclosure.
- Before every changeover, switch the load off; then move the handle and switch the load back on.
Electrical work should be done by a licensed electrician. Off-load switch: never operate it with the load running.
Frequently asked questions
- What does off-load mean?
- The switch is designed to change over only when no current is flowing. Switch the load off first; operating it under load draws an arc that burns the contacts and can be dangerous. Where switching under load is needed, use a changeover rated for on-load duty.
- Why do I need a changeover switch for a generator?
- It connects your wiring to either the mains or the generator, never both. The generator cannot back-feed the supply line, where it could injure line workers, and the mains cannot reach the generator when power returns.
- 2 pole or 4 pole — which one?
- 2 pole for a single-phase supply (phase and neutral). 4 pole for a three-phase + neutral supply: switching the neutral with the phases keeps the mains and generator neutrals separate.
- Is it automatic?
- No. It is a manual switch. For automatic changeover on a power cut, use an AMF panel or an automatic transfer switch.
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