Installers reach for the Sonesse 40 WT 404S2 when an interior shade runs on switched line voltage and nobody wants a radio in the loop. Somfy builds this one as a plain 4-wire tubular motor. Power and a control signal go in, 4 Nm at 36 rpm comes out, and the shade answers a wall switch or a relay output. Shade Motors Direct stocks it as the Somfy Sonesse 40 WT 404S2 without fast connector, SKU 1001553.
Wired control on a 40mm Sonesse
Somfy lists this reference for interior blinds and shades, and for projection screens. The WT in the name marks it as wired. No receiver sits inside the tube, so an RTS transmitter will never pair to it, and the parts that belong beside it are crowns, drives, tubes and brackets rather than remotes. Control arrives from whatever switches the 120V feed, either a maintained rocker at the wall or a relay output on a shade control panel.
Somfy's full designation reads Sonesse 40 WT 404S2 RH without Fast Connector. RH marks the round head. The store title drops that RH, so match the head style against the bracket you already have before you order. Somfy also sells the same motor with a fast connector under reference 1240377 for shops that standardize on plug terminations.
The 404S2 sits at the quiet end of interior motorization. Somfy publishes 42 dB for this reference, which keeps it welcome in a bedroom, a boardroom or a media room with a projection screen dropping in front of the lens.
Tube sizing and the crown and drive
Somfy publishes a minimum internal tube diameter of 1.46 in, which is 37mm, and a motor body of 1.39 in across. Standard 40mm roller stock clears both numbers with room for the drive to seat. Cut your tube from Somfy 40mm octagonal tube, SKU 1781154 and the geometry lines up without an adapter.
Pair a round 40mm tube with the Somfy LS40 Crown and Drive Set, SKU 9012224. Somfy also builds rubberized versions of the same interface, and the LS40 Rubberized Crown and Drive Set, SKU 9016654 puts a compliant layer between the motor and the tube wall. Octagonal stock takes the LS40 Octagonal Rubberized Crown and Drive Set, SKU 9016655, which seats on the flats rather than in a round bore.
Order the crown and drive as a matched set. A drive that spins free inside an oversized tube will chew itself, and a crown that fights the tube profile throws the shade out of square at the bottom bar.
Verified specs for the 404S2 WT
Every figure below comes from Somfy's own record for reference 1001553.
| Somfy designation | 404S2 Sonesse 4/36 2M UNIT |
| Torque and speed | 4 Nm (35 in-lb) at 36 rpm |
| Traction force | 15.44 lb |
| Power supply | 120V AC, 60Hz, 108 to 132 V |
| Current | 0.95 A |
| Consumption in operation | 110 W |
| Noise level | 42 dB |
| Protection index | IP 44 |
| Insulation class | Class I |
| Head type | Round |
| Motor external diameter | 1.39 in |
| Minimum internal tube diameter | 1.46 in |
| Limit switch | Mechanical, 40 turn capacity, +/- 15 repeatability |
| Cable | VVF, 4 conductor, 6.56 ft, white |
| Operating temperature | 32 to 140 F |
| Storage temperature | -4 to 176 F |
| Thermal protection | 4 min |
| Weight | 2.48 lb |
| Approval | UR |
| Warranty | 5 years |
| Applications | Interior blinds and shades, projection screens |
Wiring a Class I motor with no fast connector
The motor leaves the factory with 6.56 ft of white VVF cable carrying four conductors. Nothing terminates that cable, so the leads land in a junction box or a controller enclosure and an electrician makes up the connections against the wiring diagram in Somfy's 400 Series Databook. Class I means the motor needs its ground conductor bonded. Skip that step and you lose the safety path Somfy engineered into the housing.
Current draw makes circuit planning painless. Each motor pulls 0.95 A and 110 W in operation, so twelve of them on one branch circuit come to 11.4 A while they run. Shades seldom run all at once, and the 4 minute thermal protection window caps how long any single motor stays under load before it rests.
Run the motor cable back to the switch location during rough-in. Six and a half feet of factory lead reaches a header-mounted box on most pockets, and a splice inside an accessible box beats fishing a replacement lead through a finished ceiling.
Limit setting and repeatability
Somfy gives this motor mechanical limits with a 40 turn capacity and a repeatability of plus or minus 15. You set the upper and lower stops at the motor head with the limit adjusters, then cycle the shade and refine. The mechanical design holds its settings through a power loss, which matters on a commercial job where a circuit gets killed for other trades.
Forty turns of capacity covers a tall drop on 40mm stock. Measure your finished length, work out the wraps, and confirm the count before the fabric goes on the tube. The head also fixes the direction convention, so mount the motor on the side your control wiring expects and let the limits follow.
The 404S2 WT beside its Sonesse 40 siblings
Somfy built the Sonesse 40 as one mechanical platform with many control paths. The 404S2 WT shares its tube interface and its 40mm body with the RTS, Zigbee, RS485 and PoE versions of the same motor, which means a shop can stock one set of crowns, drives and tubes and still quote whatever control system the job specifies. Torque steps up through the line as well, with 6 Nm and 9 Nm references available when a wider or heavier shade needs more pull.
That shared hardware is the quiet strength of Somfy's catalog. A fabricator who learns the 400 Series crown and drive geometry once carries that knowledge across every Sonesse 40 order for years.
Confirm four things before you place the order: the tube inner diameter clears 1.46 in, the head style matches your bracket, the control system switches 120V rather than sending a radio command, and the shade weight sits inside a 4 Nm working range. With those settled, the Sonesse 40 WT 404S2 plus a matched crown and drive set gets you a complete interior shade assembly, backed by Somfy's 5 year warranty.
Frequently asked questions
Will an RTS remote operate the Sonesse 40 WT 404S2?
No. This reference carries no radio receiver. Somfy lists its embedded technology as wired, so the motor takes its commands from switched 120V power alone. For radio control on the same body, Somfy offers the Sonesse 40 RTS references, which include the receiver inside the motor.
What is the smallest tube this motor fits?
Somfy publishes a minimum internal tube diameter of 1.46 in, or 37mm, for reference 1001553. The motor body itself measures 1.39 in across. Standard 40mm roller tube clears both figures, and Somfy's 40mm octagonal stock pairs with the LS40 octagonal crown and drive set without an adapter.
How many turns will the limits hold?
Somfy rates the mechanical limit switch at 40 turns of capacity with a repeatability of plus or minus 15. Count the wraps your finished drop requires on a 40mm tube and confirm the total falls inside that window before you assemble the shade. The settings survive a power outage.
Does this motor ship with a connector on the cable?
No. The 1001553 reference carries 6.56 ft of bare white VVF cable with four conductors and no fast connector. Somfy sells the same motor with a fast connector as reference 1240377. Pick the bare lead version when an electrician terminates in a junction box on site.
Shade Motors Direct is an authorized source for genuine Somfy motorized window shade, blind, and drapery parts.
