Somfy Simu T3.5 6Nm 24V DC Motor Fit and Wiring Guide

Picking 6 Nm for a 24V DC Shade

Installers choose the Simu T3.5 when a shade runs on low-voltage DC power and the tube falls in the 40 mm class. Somfy publishes this reference as T3.5 6Nm 18rpm 24V, and the 6 Nm rating at 18 rpm covers mid-size interior shades and exterior solar screens. Check the tube bore first. The motor body measures 1.39 in across, and it seats only in a tube with an inner diameter of 1.34 in or larger.

Torque sets the weight the motor lifts. Speed sets how long the shade takes to travel. At 18 rpm this motor sits in the middle of the T3.5 range, above the 12 rpm versions that trade pace for 10 Nm and below the 23 rpm versions that give up torque for a faster roll. An installer sizing a 6 ft wide fabric shade on a 40x1 tube lands on 6 Nm more often than on either neighbour.

The motor runs 19.13 in long with the head attached. Measure the pocket before ordering, since a short headrail leaves no room for the bracket behind the motor head.

Shades and Screens It Drives

Somfy lists this motor for interior window coverings and for exterior solar screens. Both applications share the same two-wire 24V DC feed, so a single regulated supply can serve a run of shades in one room or across a patio opening.

Interior roller shades are the common fit. Blackout fabric on a 40 mm tube at 6 ft of width stays inside the torque envelope, and the 70 dB figure Somfy publishes puts the motor in the same acoustic class as the rest of the wired T3.5 family. Exterior solar screens benefit from the IP 44 rating, which covers splashing water from any direction.

Specifiers working on a low-voltage job have a second reason to pick DC here. The motor draws 0 W at rest. A panel of shades on a shared supply pulls nothing between cycles, which keeps the transformer sizing honest.

Verified Specs

Figures come from Somfy's own published data for reference 2006976 on somfypro.com and somfysystems.com.

Tube, Crown and Drive Fit

A tubular motor needs four parts around it to turn a shade: a crown that centers the motor head inside the tube, a drive that keys the motor shaft to the tube wall, a bracket that carries the head at the end of the headrail, and a control that reverses the feed. Get the crown and drive pair wrong and the motor spins inside a tube that stays still.

The Somfy T3.5 38mm Round Tube 40x1 (9001495) is the reference tube for this motor. Its 1.34 in minimum inner diameter matches the published figure exactly, so the motor seats with no shim and no filing. Order the tube cut to the finished width of the shade less the bracket allowance at each end.

Jobs that mix motor families run into crown and drive mismatches at the tube. The Somfy LS40 to LT50 Crown and Drive Adapter Kit (9013763) solves that on a retrofit where a 500 series tube already hangs in the pocket and the new motor comes from the 400 series side of the catalog. Somfy's own documentation for the T3.5 line names this kit.

Use 40 mm class crowns and drives on this motor. Parts cut for a 2 in tube will not seat on a 1.39 in body.

Wiring and Limit Setup

The motor ships with 8.2 ft of white VVF cable, two conductors, ends stripped. Wiring is direct: positive and negative from a regulated 24V DC supply, through a switch or controller that reverses polarity to reverse direction. No neutral, no earth, no capacitor. Class III insulation means the motor expects a safety-isolated low-voltage supply rather than mains at the motor end.

Size the supply from the 1.05 A rated current. Four of these motors on one shared feed draw a little over 4 A while they travel, and nothing once they stop. Specifiers running a long cable to a distant pocket should check voltage drop, since the motor holds its published performance across 18 to 30 V and a thin run of cable eats into that headroom.

The Somfy Motor Plate (9012258) mounts the head in a flat pocket where a standard pin bracket has nowhere to land. Fabricators building their own headrails use it to fix the motor head to a plate inside the channel.

Confirm the connector arrangement against the motor you receive before you cut anything back. Stripped ends give an installer room to terminate into a block, a plug or a controller input.

Limits on this motor are mechanical, with 40 turns of travel available. An installer sets them with the two adjustment screws on the head and a setting key, running the shade in short moves and advancing the stop a few clicks at a time. Count the turns. A 40 turn ceiling on a 40 mm tube covers the drop of a tall window, and a long drop on a small tube can run the count out.

Set the upper limit with the fabric rolled and the hem bar at the headrail, then set the lower limit with the hem bar at the sill. Mechanical limits hold without power, so a job that loses mains for a week comes back with the stops intact. Somfy backs the motor for five years, which is the same term the rest of the wired Simu range carries.

Parts to Order With It

Order the Somfy Simu T3.5 6Nm 18rpm 24V DC Motor (2006976) with the tube and the crown and drive set that match it. The bracket or plate depends on the pocket, and a regulated 24V DC supply with a wired reversing control finishes the kit.

Installers stocking the T3.5 line keep the adapter kit on the van. Retrofits turn up more often than new pockets, and the tube already hanging above the window rarely matches the motor in the box.

Frequently Asked Questions

What tube does the Simu T3.5 6Nm 24V motor fit?

It fits 40 mm class tube with a minimum inner diameter of 1.34 in. Somfy's reference tube for the line is the T3.5 38mm Round 40x1 (9001495). The motor body measures 1.39 in across and runs 19.13 in long, so the pocket needs clearance for the head and bracket beyond the tube length.

How many turns of travel do the limits allow?

Somfy publishes 40 turns on the mechanical limit switch. An installer sets the upper and lower stops with the adjustment screws on the head. Mechanical limits hold through a power cut, so the stops stay where they were set until someone changes them.

Can this motor run on a 12V supply?

No. Somfy publishes a 24V DC nominal supply with an 18 to 30 V operating range for reference 2006976. A 12V feed sits below that range. Somfy builds a 12V version of the same 6 Nm 18 rpm motor under a separate reference, so order by voltage rather than by torque alone.

Does the T3.5 take a radio remote?

This reference is wired, with a two-wire DC cable and a reversing control. Somfy builds the radio version of the T3.5 under the ESP Hz name, which carries the receiver inside the motor and pairs to a Simu Hz transmitter. Pick the ESP Hz line for remote control and this reference for a switched installation.

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