Short answer: The Somfy Bus and Sensor Station Power Supply (1822440) puts 24V DC on a Somfy Digital Network (SDN) RS485 bus. One unit powers up to 80 bus line devices, motors excluded, from a 100 to 240 V AC input. It also powers each animeo IP sensor station and gives a USB to RS485 adaptor temporary power during commissioning.
Keypads and hubs on an SDN bus need their own 24 volts
An SDN shade system splits power into two jobs. Low-voltage RS485 motors take power and data from a panel motor port, and 120V SDN motors run on line power at the shade. The keypads, hubs and interfaces strung along the RS485 line still need a 24V DC source, and the Somfy Bus and Sensor Station Power Supply (1822440) is the part Somfy builds for that role.
Somfy rates one unit at up to 80 bus line devices, excluding motors. Count the devices on the segment, not the shades. A 40-shade lobby with six keypads and two hubs sits well inside one supply's range, while a campus riser feeding dozens of keypads per floor needs a design pass against the SDN Connect Design Guide before you order.
Installers search for this part as "somfy bus power supply", and Somfy's own pages list it as the Bus and Sensor Station Power Supply. Both names point to reference 1822440.
Four jobs Somfy built the 1822440 to do
Somfy publishes four operating modes for this supply. An installer picks the mode from the bus layout, and the hardware stays the same.
- Power with data pass-through. Incoming SDN data enters the supply, combines with its 24V output, and leaves through the output port. Somfy points this mode at riser-based systems where the input arrives from a repeater.
- Power without pass-through. The supply plugs into an approved 120V AC outlet and feeds a bus segment from one central location. Somfy suggests it for designs that keep bus distribution in one place.
- animeo IP sensor power. The supply powers and connects an animeo IP Compact Sensor or Sensor Station. Somfy requires one power supply per Sensor Station or Compact Sensor in animeo IP systems.
- Temporary power for configuration. Connect a USB to RS485 adaptor to the output port and the programming laptop's signals reach the bus, with the supply keeping the line live while you address and set up devices.
Modes one and three belong to larger buildings. Somfy ties pass-through to riser systems fed by a repeater, and it names a Building or Sub Controller as the bus source for animeo IP sensor stations.
Somfy bus power supply specs
Somfy publishes the following figures for reference 1822440 on somfypro.com and somfysystems.com.
| Somfy name | Bus and Sensor Station Power Supply |
| Somfy reference | 1822440 |
| Output | 24V DC to the SDN bus |
| Bus type | RS485 |
| Capacity | Up to 80 bus line devices (motors excluded) |
| Input voltage | 100 V to 240 V |
| Consumption during operation | 66 W |
| Rated current | 1 A |
| Protection index | IP 20 |
| Insulation class | Class II |
| Size (L x W x H) | 3.5 x 2.12 x 1.3 in |
| Weight | 1 lb |
| Working temperature | 32 to 104 F |
| Finish | Black |
| Approvals | IC, FCC, CE, UL |
| Warranty | 5 years |
The wide 100 to 240 V input range lets one part number serve projects on different mains, and the 32 to 104 F working range keeps it inside a conditioned room or a ventilated panel.
Parts that share the bus with it
The supply feeds the bus, and three Somfy parts sit closest to it on a typical SDN layout.
The Somfy SDN Data Hub V2 (1870951) adds five RJ45 device ports to a bus line, with wiring stubs up to 200 ft. Somfy says the hub draws its power from the bus unless two or more motors connect to its device ports, in which case the motors power it. A hub can in turn power three keypads or one RTS receiver, so a hub-heavy design leans on the bus supply for each hub with fewer than two motors attached.
The Somfy SDN PowerConnect Surface-Mount Panel (1871026) adds 10 isolated motor ports and 2 isolated device ports to a bus segment. Each motor port runs power and data up to 240 ft to a low-voltage intelligent motor, and Somfy lists the Sonesse 30 RS485 24V DC and Sonesse ULTRA 504 A8 DC RS485 as compatible motors. Its two device ports draw from the panel's internal supplies.
The Somfy USB to RS485 Adaptor for SDN (9015260) is the part Somfy names on the 1822440 page. Plug it into the supply's output port during setup and your laptop talks to the bus while the supply holds power on the line.
Keep RTS remotes and WireFree wall switches off an SDN parts list. RS485 motors carry no radio receiver, and app or voice control on an SDN job comes through the Data Hub and the building's control system. Our Somfy control systems comparison lays out where SDN fits beside RTS and Zigbee.
Commissioning an SDN bus with the 1822440
Commissioning an SDN job means addressing each motor and keypad and setting motor limits from a laptop, and the bus has to carry power while you work. Somfy lists temporary configuration power as one of the 1822440's four modes. Plug the supply into a 120V outlet, connect the USB to RS485 adaptor to its output port, and your configuration software reaches the bus.
Somfy lists its Configuration Software and the SDN Set pro by Somfy User Guide (V2.0) among the 1822440 documents. For IP-based commissioning, the UAI Plus SDN commissioning guide covers the interface side. Motor-side wiring for a 24V RS485 roller shade motor sits in our Sonesse 30 RS485 wiring guide.
Mounting, environment and ordering notes
The supply carries an IP 20 rating, so it belongs indoors in a dry space. At 3.5 x 2.12 x 1.3 in and 1 lb, it fits beside an outlet in an equipment closet or a low-voltage panel. Class II insulation and UL, FCC, IC and CE approvals cover North American and export jobs.
Order one 1822440 per animeo IP Sensor Station or Compact Sensor, plus one for each bus segment the SDN Connect Design Guide tells you to feed from a central supply. Somfy publishes the design guide, the Bus Power Supply spec sheet and the physical spec sheet for this part, and you can pull Somfy documents for the rest of the system from our Somfy spec sheet library.
Browse the Somfy SDN digital network parts for RS485 motors, keypads, cable and the commissioning tools, then order the Somfy Bus and Sensor Station Power Supply (1822440) to power the bus.
Somfy bus power supply FAQ
How many devices can one Somfy bus power supply run?
Somfy rates the Bus and Sensor Station Power Supply (1822440) at up to 80 bus line devices. Motors do not count toward that figure, since low-voltage RS485 motors take power from panel motor ports and 120V SDN motors run on line power. Keypads, hubs and interfaces count. Lay out larger systems against Somfy's SDN Connect Design Guide.
Does the 1822440 power SDN motors?
No. Somfy excludes motors from the supply's 80-device rating. A 24V RS485 motor such as the Sonesse 30 RS485 takes power and data from a motor port on an SDN PowerConnect panel, which runs up to 240 ft to each motor. The 1822440 powers the bus line devices around those motors, such as keypads and Data Hubs.
What input voltage does the Somfy bus power supply need?
Somfy lists an input range of 100 V to 240 V, and its benefits list describes plugging the unit into an approved 120V AC outlet. Output is 24V DC to the SDN bus. Somfy publishes 66 W consumption during operation and a 1 A rated current. The unit carries IP 20 and Class II ratings for indoor dry locations.
Do I need one bus power supply for each animeo IP sensor?
Yes. Somfy states that animeo IP systems require one power supply per Sensor Station or Compact Sensor. The 1822440 powers the sensor and connects it to the bus. Somfy also publishes a Weather Station M Sensor wire detail, WSM-WIRING-01, for animeo IP or IB+ systems among this part's installation documents.
Sources: Somfy Bus and Sensor Station Power Supply, ref 1822440, on somfypro.com (e-cat) and somfysystems.com; Somfy SDN Data Hub V2, ref 1870951, and SDN PowerConnect Surface-Mount Panel, ref 1871026, on somfysystems.com.
Shade Motors Direct is an authorized source for genuine Somfy motorized window shade, blind, and drapery parts.
