Choosing a Somfy Power Supply for 24V DC Shade Motors

Short answer: A Somfy 24V DC motor needs a Somfy 24V DC supply. For one shade, use the 24V DC 1.67 A plug-in transformer (1822209) at a nearby outlet. For a bank of shades, use a Somfy Power Distribution Enclosure Kit sized for 5, 10, 15 or 20 motors, which feeds fused outputs from one 120V AC input.

Somfy builds its quietest small-tube motors on 24V DC. The Sonesse 30 family and the Sonesse ULTRA 504A8 DC run on low voltage, so the power plan belongs in the shade order, alongside torque and tube size. A mismatched supply leaves the motor dead at the bracket. Get it right once and the wiring closet stays tidy for years.

Somfy motors that run on 24V DC

Start with the motor label. Somfy prints the supply voltage on it, and the product name carries it too. The 24V DC motors stocked here include the Somfy Sonesse 30 RTS 24V DC (1241142), the Somfy Sonesse 30 DCT 24V DC (1241146) for dry contact keypads and third-party controllers, plus the Sonesse 30 RS485 and Sonesse 30 Zigbee versions and the Sonesse ULTRA 504A8 DC RTS.

Somfy publishes the Sonesse 30 load in its 24V DC Low-voltage Motor Range Databook: 0.8 A nominal, a 1.8 A starting peak for up to 300 ms, and up to 3.2 A for 300 ms during programming. The Sonesse ULTRA 50 DC carries a 1.5 A rated current. Size the supply for the peak draw.

Battery motors sit outside this guide. A Sonesse 30 WireFree or Roll Up WireFree carries its own pack and charger, covered in our WireFree vs wired motor comparison. A 120V AC motor such as an LT50 takes line voltage through SJTW cable and needs no transformer at all.

One shade: the 24V DC plug-in transformer

The Somfy 24V DC 1.67 A Plug-in Wall Mount Transformer (1822209) runs one motor from a standard outlet. Somfy lists it for R28 and Sonesse 30 motors, ships it with a 6 ft cable, and backs it with a 5 year warranty. The databook rates it for one motor, with a body of 3.5 x 2.3 x 1.3 in.

This route suits a retrofit with an outlet near the head of the shade, a single bedroom blackout, or a test motor on the bench. It costs $52.87 per motor here and needs no electrician. Six shades on six transformers means six outlets and six bricks, though, and the per-window approach gets untidy past two or three openings.

Several shades: Power Distribution Enclosure Kits

Somfy's Power Distribution Enclosure Kits take one 120V/60Hz input and split it into fused 24V DC outputs, one per motor. Each kit arrives assembled in a UL listed grey enclosure, with an LED per output that shows power to each motor and plug-in connectors for the motor leads. Somfy rates them IP 20, Class II, for 41 to 122 F, with a 5 year warranty. Plan on a dry, conditioned location such as a mechanical closet or a ceiling plenum access point.

Somfy lists the enclosures for the Sonesse 30 RTS, DCT, RS485 and Zigbee 24V DC motors and the Sonesse ULTRA 504A8 DC RTS. Size the kit to the motor count you expect to reach, with a spare port or two for a shade added later. A 7 shade living room fits the 10 motor kit with three ports left over.

Plug-in transformers or an enclosure?

On a small job, plug-ins cost less. Two shades on 1822209 transformers come to about $106. Five shades on plug-ins run about $264, against $901.99 for the 5 motor enclosure.

Installers choose the enclosure for reasons other than price:

• One serviceable point for the whole run, with an LED per motor to confirm power during troubleshooting.
• Fused outputs, so a fault on one shade stays on that port.
• No outlet needed at the window, which matters in new construction with recessed pockets.
• One line-voltage connection in place of a transformer at each opening.

For new construction and pre-wired homes, specify the enclosure. For a retrofit with outlets already at the window heads, stay with plug-ins.

Wire gauge and run length

Voltage drops over a long low-voltage run, so Somfy publishes a maximum power cable length per gauge to guarantee motor performance. Keep each home run from the enclosure to the motor inside these limits:

On the Sonesse 30 RTS and RS485, Somfy uses a 2 pin JST connector at 2 mm pitch, with the striped conductor positive and the white conductor negative. Somfy states that its own power supplies keep the UL listing and the motor performance intact, and that terminal blocks and wiring follow local electrical codes. Have a licensed electrician make the 120V connection to the enclosure. The motor-specific wiring details sit in the Somfy spec library, and the Sonesse 30 tube and bracket fit sits in our Sonesse 30 RTS 24V DC fitment guide.

SDN projects: the PowerConnect panel

A Somfy Digital Network job wires power and RS485 data to each motor. For that, Somfy offers the Somfy SDN PowerConnect Surface-Mount Panel (1871026). It provides 10 isolated motor ports and 2 isolated device ports with internal power supplies, supports up to 240 ft of power and data wiring, and carries a 5 year warranty. Somfy lists it for the Sonesse 30 RS485 24V DC and the Sonesse ULTRA 504A8 DC RS485.

Choose the PowerConnect panel for a networked commercial or high-end residential system with a keypad bus and a control processor. An RTS or DCT house of a dozen shades stays with the enclosure kits. Our RTS, Zigbee, SDN and wired comparison lays out the control side.

Picking the supply, step by step

Work through the job in this order before you order parts:

1. Read the voltage on each motor label and keep the 24V DC motors on one list.
2. Count those motors and add any shades planned for a later phase.
3. Mark the outlets at each window head. One or two motors with outlets nearby go on 1822209 plug-ins.
4. For five or more, or for a project with no outlets at the windows, pick the enclosure size from the table above.
5. Measure each run from the enclosure location to the motor and choose 14, 16 or 18 AWG to stay within Somfy's limits.
6. For RS485 motors on an SDN bus, plan the PowerConnect panel in place of an enclosure kit.

The full range of transformers, enclosures, cables and chargers sits in our Somfy power supplies and enclosures collection.

FAQ

Can one Somfy 24V plug-in transformer run two motors?

Somfy rates the 24V DC 1.67 A plug-in transformer (1822209) for one motor. A Sonesse 30 draws 0.8 A in normal running, but it peaks at 1.8 A on start and up to 3.2 A during programming. Give each motor its own transformer, or move to a Power Distribution Enclosure Kit once you reach several shades on one project.

Does the Somfy power distribution enclosure plug into an outlet?

The enclosure kits take a 120V/60Hz input and arrive assembled in a UL listed enclosure. Somfy states that terminal blocks and wiring follow local electrical codes, so plan for a licensed electrician to make the line-voltage connection. The 24V DC side then runs to each motor through fused outputs with plug-in connectors and a power LED per port.

How far can a 24V Somfy motor sit from its power supply?

Somfy publishes the maximum power cable length by wire gauge: 240 ft on 14 AWG, 150 ft on 16 AWG and 100 ft on 18 AWG. Those limits guarantee motor performance at the far end of the run. Measure the longest run on the job first, then choose the gauge that keeps it inside Somfy's figure.

Do Somfy Zigbee and DCT 24V motors use the same enclosure as RTS?

Yes. Somfy lists the Power Distribution Enclosure Kits for the Sonesse 30 RTS, DCT, RS485 and Zigbee 24V DC motors and the Sonesse ULTRA 504A8 DC RTS. The enclosure supplies power only. Control stays with the motor's own protocol, so RTS remotes, dry contact keypads and Zigbee hubs work as they would on a plug-in transformer.

Sources: Somfy 24V DC Low-voltage Motor Range Databook (Sonesse ULTRA 50 and Sonesse 30, 5-2019); Somfy product pages for the Power Distribution Enclosure Kits 1870196 and 1870192, the 24V DC 1.67 A Wall Mount Power Supply 1822209, and the SDN PowerConnect Surface-Mount Panel 1871026 on somfysystems.com and somfypro.com.

Shade Motors Direct is an authorized source for genuine Somfy motorized window shade, blind, and drapery parts.