Combination Rotary Dimmers and Toggle Switches by Forbes & Lomax — Metal

The Metal Combination Plate by Forbes & Lomax pairs rotary dimmers and toggle switches on a single metal plate, based on the elegant nickel and brass switches of the 1930s. Plate and mechanisms are supplied in the same finish.

Established in 1987, Forbes & Lomax is a UK-based heritage electrical brand recognized by architects and designers for refined switch and outlet design.

• Can I order online? Yes, if your lights are standard dimmable LED and one of the six fixed layouts below suits your position. Standard means a line voltage bulb or fixture that dims on its own, with no driver, transformer or power supply in the run. If there is one, the module is chosen by that device rather than the fixture, so check Electrical & LED Compatibility below.
• What should I confirm? Junction box depth, and that each device on the plate has its own circuit. A 4 gang plate needs four circuits behind it. Your electrician will know both.
• When should I request a custom quote? Drivers, transformers, 0-10 V, any layout not listed below, or anything you are unsure about should be confirmed by our sales team in order to ensure compliance and compatibility. Please reach out to us at contact@cassonhardware.com.
• Can I install it myself? No. Line voltage, licensed electrician only.

Full specifications, module ratings and installation requirements are below.

Each combination is a fixed layout. Dimmers and toggles can be repositioned on the plate during installation.

Toggles, rotary dimmers, push buttons and outlets can be mixed on the same plate, and multi-gang plates up to 8 gang are supplied to accommodate as many devices as required. Contact us with your device schedule for any layout not listed above.

Plate widths for each gang count are listed under Specifications below.

• Supply: line voltage, for conventionally wired installations.
• Toggle: 3-way, 15 A. Works as single pole or 3-way. 4-way available on request.
• Rotary dimmer: LED module only on this plate, max. 120 W LED or 300 W incandescent / halogen (TRIAC).
• Specialty modules: incandescent, magnetic low voltage and 0-10 V are available in every finish by request. They are needed only when a specific fixture calls for one, so they are not sold online.
• Minimum load: no formal minimum is stated for the LED module, though Forbes & Lomax recommend at least 5 W. Below that the dimmer may not register that a fixture is connected.
• Electronic low voltage: not supported. Forbes & Lomax do not make an ELV or reverse phase dimmer. Where a fixture requires one, a non-dimming toggle switch is the only option.

Dimming LED

Dimming LED is difficult across the whole lighting industry, not just this range. Compatibility can usually be predicted from a fixture's specification sheet, which is why we ask for it, but some trial and error is normal. Send your lighting schedule to contact@cassonhardware.com and we will review it with Forbes & Lomax.

• Guarantee: Forbes & Lomax cannot guarantee that every fixture labelled dimmable will dim satisfactorily on a TRIAC module. Performance depends on the make of fixture and the driver inside it.
• Minor flickering: even on a compatible fixture, some flickering can occur at the top or bottom of the range. Optimizing the dimming range resolves most of it.
• Bulb recommendation: for screw-in LED, Forbes & Lomax recommend Philips Ultra Definition. They dim smoothly to low levels and hold colour quality.
• Testing on site: where a fixture is unusual and you need certainty before committing to a full order, buy a single dimmer and test it in place.
• One lighting type per dimmer: recessed lights and a chandelier on the same dimmer will perform poorly even where each is individually compatible.

• Electrician: must be installed by a licensed electrician, in accordance with appropriate electrical codes and regulations.
• Circuits: each device on the plate is its own circuit. A 4 gang plate with two dimmers and two toggles needs four separate circuits behind it. Confirm the box and wiring support the layout before ordering.
• Circuit position: a dimmer can be wired at only one position on a 3-way or 4-way circuit. Every other position must be a non-dimming toggle. This is why most combination plates pair one dimmer with toggles rather than several dimmers.
• Junction box depth: recessed at least 1/8" below the finished wall surface so the plate sits flat. Refer to the Junction Box Assembly Diagrams below. Check existing boxes before ordering.
• Non-dimming: rotary switches are available where a rotary style is wanted but only push on/off is required.
• Optimizing: the dimmer selects the correct dimming mode automatically once connected. Set the minimum and maximum levels for your fixtures, then apply the Program Lock. On a compatible fixture this resolves most flickering. Changing the mode by hand is a last resort, after optimizing has been tried.
• Momentary switches: not line voltage. They work only with home automation systems including Lutron Homeworks, Crestron, Savant, Vantage and Control 4.
• Areas of application: light-duty commercial, residential.

Layouts not listed above, and any circuit with a driver, transformer or 0-10 V dimming, are quoted by our sales team. Send the following to contact@cassonhardware.com and we will price it against your schedule.

• Combination layout and gang count for each plate
• Fixture make and model on each dimmed circuit, and the driver or transformer type if there is one
• Total connected wattage per dimmer
• Number of switching positions on each circuit
• Fittings finish
• Junction box depth on site

Plate Sizes

All plates are 4.53" (115 mm) high and 1.8 mm thick.

Device Dimensions

• Switch and knob: Ø 0.79" (20 mm).

• Plate: solid metal, finished by hand. Plate and mechanisms are supplied in the same finish.
• Aged Brass: a plate finish only. Forbes & Lomax do not make Aged Brass mechanisms, so the toggle, knob and screws are supplied unlacquered brass and patina alongside the plate rather than matching on arrival.
• Living finishes: Unlacquered Polished Brass and Aged Brass darken and develop a patina with handling and exposure. This is intended and not a defect, and variation between pieces is normal.
• Lacquered finishes: Nickel Silver, Brushed Stainless Steel, Antique Bronze, Lacquered Brushed Brass and Matte Brass hold a consistent colour and will not change.
• Matte Brass: carries a baked lacquer coating that resists fingerprints.
• Care: wipe clean with a dry, non-abrasive microfiber cloth. Avoid chemical or alcohol-based cleaners.

Available Finishes

• Unlacquered Polished Brass
• Aged Brass (plate finish only)
• Nickel Silver
• Brushed Stainless Steel
• Antique Bronze
• Lacquered Brushed Brass
• Matte Brass

• Toggle switches: conform to UL 20, certified to CSA C22.2 No. 111.
• Rotary dimmers: conform to UL 1472, certified to CSA C22.2 No. 184.

Review and ensure all certifications are applicable for your local code.

Product Sheets

• Rotary Dimmer Cut Sheet
• Toggle Switch Cut Sheet
• Plate Dimensions
• Forbes & Lomax Brochure

Dimmer Documentation

• 120 W LED / 300 W Incandescent — Wiring Instructions
• 120 W LED — Optimization Instructions
• 120 W LED — Compatibility & Troubleshooting Tips

Installation & Assembly

• General Instructions for Electricians (Switches & Dimmers)
• Toggle Switch Installation Instructions
• Junction Box Assembly Diagram (Rotary Dimmer)
• Junction Box Assembly Diagram (Toggle Switch)
• Circuitry Visual Aid
• Home Automation Integration

Plates & Finishes

• Finish Swatches
• Custom Engraving
• Plate Cleaning Guidelines
• Sustainability Statement