The Sonesse 40 406A2 WT sits in the middle of Somfy's wired 400 Series range at 6 Nm and 24 rpm, and it ships with a Fast Connector pigtail in place of stripped leads. Shade shops reach for it when the tube is 40 mm, the circuit is 120V, and the job calls for a quiet interior motor that an electrician can land in seconds. Somfy builds this one as a round head motor, reference 1240378.
Tube Diameter Decides This Motor
Somfy publishes a minimum internal tube diameter of 1.46 in for the 406A2 WT. Measure the inside of your tube before you order. The motor body measures 1.57 in across and 1.39 in at the external diameter, so a 40 mm octagonal or round tube swallows it with room for the crown to seat square. Installers who force a narrower tube over this motor bind the drive and lose the limit repeatability Somfy rates at plus or minus 15.
Unwrapped length runs 20.08 in, and Somfy gives the riveting position distance as 18.62 in. Mark the drive screw against that figure, not against the end of the tube. Cut the tube after you have the bracket, the idle end and the motor head in front of you.
Shades the 406A2 WT Drives
Somfy lists interior window coverings and projection screens for this reference. 6 Nm covers solar and roller shades at residential and light commercial widths, roman and woven shades on a 40 mm tube, and horizontal blinds built on the same platform. Traction force comes in at 15.44 lb. Fabric weight, tube deflection and roll-up diameter set the real ceiling, so a wide blackout roller on a long span belongs on the 9 Nm 409R2 instead.
24 rpm gives a travel speed that suits interior work. Guests in a conference room hear 44 dB from this motor, which keeps it off the list of distractions during a presentation. Projection screen builders use that number to decide whether the motor runs during a dimmed scene or between cues.
Verified Specs for Reference 1240378
| Specification | Published figure |
|---|---|
| Somfy reference | 1240378, Sonesse 40 WT 406A2 RH with Fast Connector |
| Torque and speed | 6 Nm (53 in-lb) at 24 rpm |
| Traction force | 15.44 lb |
| Power supply | 120V / 60 Hz, range 108V to 132V |
| Rated current | 0.95 A |
| Power in operation | 120 W |
| Standby draw | 0.46 W |
| Noise level | 44 dB |
| Protection index | IP 44, interior use |
| Insulation class | Class I |
| Head type | Round |
| Minimum internal tube diameter | 1.46 in |
| Motor diameter | 1.57 in, external diameter 1.39 in |
| Unwrapped length | 20.08 in |
| Riveting position distance | 18.62 in |
| Limit capacity | 40 turns, set at the motor head |
| Limit repeatability | Plus or minus 15 |
| Cable | 2464, 4 conductor, white, 1.64 ft, Fast Connector ends |
| Weight | 2.76 lb |
| Operating temperature | 32 F to 140 F |
| Storage temperature | -4 F to 176 F |
| Thermal protection | 4 minutes |
| Approval and warranty | UR, 5 year Somfy warranty |
Every figure above comes from Somfy's own published data for reference 1240378 on somfypro.com and the Somfy 400 Series Databook.
Crowns, Drives and the Tube It Rides In
A Sonesse 40 needs an LS40 crown and drive pair matched to the tube profile. The Somfy LS40 Crown and Drive Set (9012224) handles standard 40 mm round tube. Shops working octagonal stock take the LS40 Octagonal Rubberized Crown and Drive Set (9016655), where the rubber face damps the start and stop knock that a hard crown passes into the headbox. The round-tube rubberized version, the LS40 Rubberized Crown and Drive Set (9016654), does the same job on round stock.
Tube comes from the same shelf. Order Somfy 40 mm Octagonal Tube (1781154) by the foot in 20 ft increments and cut to your finished width. Keep 400 Series parts on a 400 Series motor. A 50 mm crown will not hold this motor head, and 28 mm parts will not seat on the drive.
Fast Connector Power and Wiring
The Fast Connector is the reason shops specify this version over the stripped-lead 406A2. Somfy fits a 1.64 ft, 4 conductor 2464 pigtail with connector ends, so an installer mates the motor to a matching Fast Connector lead and closes the headbox. No wire nuts, no field stripping, no second trip when the shade needs to come out of the pocket for service.
Somfy drives the WT line by switching power. Control arrives from a maintained wired switch, a relay output, or a controller channel wired as a dry contact. Give the motor a dedicated 120V branch sized for 0.95 A and 120 W in operation, and count 0.46 W at rest when you total a large wall of shades. A motor with no onboard radio receiver takes no commands from an RTS handheld, so radio control on this platform comes through a Somfy interface placed upstream of the motor.
Limits, Mounting and Setup Notes
The 406A2 WT carries a 40 turn limit capacity, and the installer sets both stops at the motor head. Run the shade to the top stop first, then the bottom, then cycle the shade twice and check the hem against the sill. Repeatability of plus or minus 15 means a shade that lands within a tolerance a client will accept across a bank of openings, provided every shade in the run gets the same sequence.
Somfy specifies two self-tapping screw holes for the drive wheel, 4 mm across and 29 mm apart, with the screws in the box. Thermal protection cuts the motor after 4 minutes of continuous run, which matters during commissioning when a technician cycles one shade over and over. Give it ten minutes and it comes back. Keep the motor inside 32 F to 140 F, since IP 44 and Class I insulation put this reference indoors.
What tube does the Somfy 406A2 WT fit?
Somfy publishes a 1.46 in minimum internal tube diameter for reference 1240378, which places it in 40 mm round and octagonal tube. Pair it with an LS40 crown and drive set matched to your tube profile. Check the inside dimension of the tube you own, since wall thickness changes the clear bore on nominal 40 mm stock.
Does the 406A2 WT take an RTS remote?
No. Somfy builds the WT line as a wired power-switching motor with no onboard receiver, so an RTS handheld has nothing to pair with. Control comes from a maintained wall switch or a relay output. Shops that want radio or app control on a wired motor add a Somfy interface upstream rather than a remote at the motor.
What is the difference between the 406A2 WT and the 409R2 WT?
Torque and speed. The 406A2 WT delivers 6 Nm at 24 rpm, and the 409R2 WT delivers 9 Nm at 14 rpm. Both share the 40 mm platform and the same tube requirement. Take the 409R2 for a heavier fabric or a wider shade, and the 406A2 for the travel speed.
How long is the Fast Connector cable on this motor?
Somfy gives the pigtail as 1.64 ft of 4 conductor 2464 cable in white, terminated with Fast Connector ends. Plan a matching Fast Connector extension lead from the motor to the junction, and allow enough slack at the head to lift the tube out of the brackets for service.
Order the Sonesse 40 406A2 WT
Buyers who have the tube, the bracket and a 120V circuit in hand can order the Somfy Sonesse 40 406A2 WT 120V 4-Wire Motor with Fast Connector (1240378) and add the crown and drive set that matches the tube profile. Pair it with 40 mm octagonal tube on a new build, or drop it into an existing 400 Series shade and reuse the crown you already have.
Shade Motors Direct is an authorized source for genuine Somfy motorized window shade, blind, and drapery parts.
