Installers settle two questions before torque on a small shade motor: tube diameter and supply voltage. The Simu T3.5 10Nm 12rpm 24V, Somfy reference 2006978, answers both at the compact end of the range. It carries 10 Nm at 12 rpm, draws 29 W under load, and runs on a regulated 24V DC supply. Somfy lists it for interior window coverings and exterior solar screens.
Pick this motor when the shade runs on 24V DC
A 24V DC tubular motor earns its place where a line-voltage feed costs more than the shade itself. You pull two low-voltage conductors to the head box, land them on a regulated supply, and skip the work an AC motor would ask for at the pocket. Somfy rates this one at 29 W running and 0 W at rest. Size the supply against the running draw of every motor on the circuit and a single transformer feeds a bank of shades.
The T3.5 body is small. Minimum tube inner diameter sits at 1.34 in, which puts 40 mm class tubes in reach and rules out anything tighter. Shops that build 38 mm round tube and 40 mm octagonal tube pair this motor with a T3.5 crown and drive and move on.
Somfy builds the T3.5 line in both 12V and 24V DC. Reference 2006978 is the 24V version at 10 Nm. A 24V supply holds voltage better over a long run than a 12V supply of the same gauge, which matters once the transformer sits in a closet and the shade sits across the building.
Shades the 10 Nm T3.5 drives
Ten newton metres covers a lot of interior fabric. On a 38 mm tube that torque lifts a roller shade in blackout or solar screen cloth, and it absorbs the extra drag an exterior screen picks up from its side channels. Somfy publishes two applications for this reference: interior window coverings and exterior solar screens.
Torque alone never settles a shade. Fabric weight, tube deflection across the span, friction from a cassette or side track, and the mass of the hem bar all pull against the motor. Installers who size by finished weight and drop, then check the tube for sag at the midpoint, land on the right motor the first time. The 12 rpm output gives a measured travel speed that suits a tall interior shade and keeps a solar screen from slapping its channels on the way down.
Somfy backs the motor with a five year warranty. That figure carries weight on a commercial job where the ceiling goes back up after the shades go in.
Verified specifications
| Somfy reference | 2006978 |
| Somfy product name | T3.5 10Nm 12rpm 24V |
| Model designation | MOTOR T3,5 10NM/12RPM 24VDC X1 |
| Torque and speed | 10 Nm at 12 rpm |
| Power supply | 24V DC |
| Rated current | 1.2 A |
| Power consumption | 29 W running, 0 W standby |
| Noise level | 72 dB |
| Protection rating | IP 44 |
| Insulation class | Class III |
| Control | Wired, 2-wire DC |
| Limit switch | Mechanical, 40 turns of travel |
| Head type | Round |
| Minimum tube inner diameter | 1.34 in |
| Motor length | 14.69 in |
| Cable | VVF, 2 conductor, white, 8.2 ft, stripped ends |
| Operating temperature | -4°F to 140°F |
| Applications | Interior window coverings, exterior solar screens |
| Warranty | 5 years |
Figures come from Somfy's published data for reference 2006978.
Tube, crown and drive fit
The 1.34 in minimum inner diameter sets the floor. Anything narrower will not take the motor body, and a tube that clears the body by a wide margin leaves the drive wheel doing work the tube wall should share. Match the crown and drive to the exact tube profile rather than to its nominal size.
For 40x1 round tube, the Somfy T3.5 38mm Round crown for 40x1 tube (9001495) is the direct pairing. It seats the motor head in the tube and transfers torque through the matching drive profile. Order it with the motor so the shade goes together in one pass.
Fabricators who stock 50 series tube can still run this motor. Somfy's 400 Series to 500 Series Crown and Drive Adaptor Kit (9013763) steps a 40 series motor up to 50 series crown and drive parts, and Somfy rates the kit to 13 Nm of motor torque, which clears this motor's 10 Nm with room to spare. Somfy names reference 2006978 in the kit's own compatibility list.
At the idle end, the Somfy Motor Plate (9012258) gives the motor head a flat surface to land against in a pocket or bracket assembly. Pick the plate or a T3.5 bracket to suit the head box you are building into.
Wiring and limit setup
The motor ships with 8.2 ft of white VVF cable, two conductors, stripped at the ends. Two wires mean direction comes from the polarity you feed the motor, so the control device reverses polarity to send the shade the other way. Land the cable on a regulated 24V DC supply through a DC wall switch or a DC receiver, and keep the run short enough that voltage drop stays off the motor's performance.
Limits are mechanical, with 40 turns of travel available. You set upper and lower stops at the head with the adjustment screws and a setting tool, run the shade to each end, and trim until the hem bar lands where the drawing says. Mechanical limits hold their setting through a power loss, which is one reason specifiers keep choosing them on simple wired shades.
IP 44 and Class III insulation suit the motor to a protected exterior position such as a recessed solar screen pocket or a soffit. Operating temperature runs from -4°F to 140°F. Confirm the connector arrangement against the motor you receive before you cut or extend the lead.
Parts to order with the motor
The Somfy Simu T3.5 10Nm 12rpm 24V DC Motor (2006978) ships as the motor alone. Build the kit around it: a crown and drive matched to your tube, a bracket or plate at the head, an idle end assembly, a regulated 24V DC supply sized for the bank, and a wired DC control.
Two parts cover most 40 mm class builds. The T3.5 38mm Round crown for 40x1 tube (9001495) handles the common round profile, and the 400 to 500 Series adaptor kit (9013763) opens the 50 series parts bin when the tube calls for it. Add the Motor Plate (9012258) when the head needs a flat mounting face.
Frequently asked questions
What tube does the Simu T3.5 10 Nm 24V fit?
The motor needs a tube with at least 1.34 in of inner diameter, which covers 40 mm class tube including 38 mm round and 40 mm octagonal profiles. Pair it with a T3.5 crown and drive cut for your exact tube. Somfy's 400 to 500 series adaptor kit extends the motor to 50 series crown and drive parts.
How many shades can one 24V supply run?
Each motor draws 29 W while running and 0 W at rest. Add the running watts of every motor that could move at the same time, add headroom, and select a regulated 24V DC supply at or above that figure. Shades that move in sequence rather than together let a smaller supply do the work.
Does this motor work with a Somfy RTS remote?
Reference 2006978 is a wired motor with a two conductor lead and no radio receiver inside. Control comes from a wired DC switch or from a separate DC radio receiver wired between the supply and the motor. Specify the receiver with the motor if the job calls for handheld control.
Where does Somfy rate this motor for use?
Somfy publishes two applications for reference 2006978: interior window coverings and exterior solar screens. The IP 44 rating and Class III insulation suit a protected exterior position such as a recessed pocket or soffit. Operating temperature runs from -4°F to 140°F.
Shade Motors Direct is an authorized source for genuine Somfy motorized window shade, blind, and drapery parts.
