A client picks a smart brushed steel grid plate with a module printed PRESS, and asks for it to run the hallway light. It gets wired in, and the light comes on for exactly as long as a finger stays on the rocker. Nothing is faulty. It is doing precisely what a retractive switch is built to do.

What Makes a Retractive Switch Different?

A normal light switch latches. Flick it down and it stays down, holding the circuit closed until someone flicks it back. A retractive switch has a spring that returns the rocker to its resting position the instant you let go, so the contact only closes for the length of the press.

That sounds like a limitation, and for switching a lamp directly it is. The point is that a momentary press is exactly the signal a lot of other equipment wants: a pulse that says "do something now" without the switch having to carry the load or remember its own state.

On BG's grid range these modules are clearly marked. The standard retractive modules carry a PRESS legend on the rocker, and BG's own R14C product page lists the centre-off version as giving a centre off position for dual circuit control, with a 25mm minimum box depth and an IP20 rating.

Four Jobs a Retractive Switch Actually Does

Bell pushes. The simplest case. The bell rings for as long as the button is held. Many bell circuits run at extra-low voltage from a transformer, and a grid module rated 20AX at 230V is comfortably inside its limits at those voltages, since the rating is a maximum rather than an operating requirement.

Latching relays. This is where retractive switches earn their keep on bigger jobs. A latching (impulse) relay changes state on every pulse it receives, so any number of retractive switches wired in parallel to it can all switch the same light. Each switch only needs a simple feed and return rather than the strapping wires a two-way and intermediate arrangement needs. If you are weighing this against conventional wiring, our intermediate switching guide explains how the traditional three-point method works.

Door entry and access control. Plenty of door entry panels and exit buttons expect a momentary contact rather than a latching one. Follow the system manufacturer's wiring diagram exactly: on any door that forms part of a fire escape route, how the release behaves on alarm or power loss is set by the access control design and the building's fire strategy, not by the switch.

Blinds and screens. Motor controllers for blinds, projector screens and awnings often want two separate momentary inputs, one for up and one for down. A centre-off retractive module gives exactly that from a single rocker: press the top for one direction, the bottom for the other, and it returns to the neutral middle position on release.

1-Way Retractive or Centre-Off: Which Module?

Pick by how many separate signals the job needs from one rocker.

• One signal: a standard 1-way retractive module (PRESS). Bells, relay pulses and most door entry inputs fall into this group. On TEO these sit in the 20A grid module range across white, brushed steel, matt black, polished chrome and BG Evolve finishes.
• Two opposite signals: a centre-off retractive module. Use this where a controller needs separate up and down, open and close, or raise and lower inputs.
• A full plate rather than grid: BG Evolve 10AX 1-way press switches come as a complete single-gang plate, useful where a lone bell push or relay button needs to match an Evolve scheme without building a grid plate.

Remember that grid modules need a matching grid frame and front plate, so order all three together, and keep the finish consistent with the rest of the switches in the room.

The Mistakes That Cause Callbacks

• Using a retractive switch to switch a light directly. The light will only stay on while the switch is held. If the brief is a normal light switch, fit a normal switch.
• Mixing up retractive and centre-off latching modules. A centre-off switch that latches in each position behaves very differently from a centre-off retractive that springs back. Check the product description before ordering.
• Forgetting the grid frame and plate. A module on its own cannot be fitted. Build the plate, frame and modules as one order from the BG grid range.
• Ignoring the equipment's own instructions. Bell transformers, relays, door entry panels and blind controllers all specify their input wiring. The switch has to suit the equipment, not the other way round.