Somfy 535A2 LT50 35 Nm Wired Motor Fit and Torque Guide

A clear inside tube diameter of 1.85 inches is the figure that puts the Somfy LT50 535A2 on a parts list. Measure the tube first. The 535A2 produces 35 Nm of torque, 310 inch-pounds, at 20 rpm on 120V house power, and it delivers that load through a star head and a snap-on drive wheel. Awning and rolling shutter builders reach for it when the assembly runs from a wall switch instead of a remote.

Match the tube and the load before the part number

Somfy sizes the LT50 family around tube diameter, and the 535A2 needs 1.85 inches of clear space inside the tube. Shutter and awning tubes in the 50 to 70 mm range clear that figure. Torque comes second. 35 Nm moves a heavy rolling shutter curtain or a wide folding arm awning without strain, and the 20 rpm output keeps travel time short on a tall opening. Pair those two numbers and the part choice follows. An installer who skips the tube measurement ends up with a motor that will not enter the tube at all.

Overall length matters on a narrow shutter box. The 535A2 measures 24.13 inches from the head to the drive tip, so the tube plus the bracket plus the idler end has to fit inside the box width you have. Check that dimension against the opening before you cut tube.

Awnings and rolling shutters the 535A2 drives

Somfy lists awnings and rolling shutters as the applications for this reference. On an awning, 35 Nm handles a folding arm or cassette assembly where fabric width and arm hardware add up fast. On a rolling shutter, the same torque lifts an aluminum or steel curtain across a wide window or a patio door. Exterior screens built on a 2.5 inch round tube also sit inside its range. The IP 44 protection index covers the splashing water and the dust that collect in an exterior shutter box, which is why Somfy rates the LT50 line for outdoor service.

Verified specs for the LT50 535A2

Somfy publishes the 250 W consumption figure, the IP 44 index, the UR approval and the 38.8 kg carbon figure against reference 1047368 on its own product page. The 535A2 designation reads as a 500 series motor at 35 Nm, and the SJTW suffix names the cable jacket Somfy fits to the wired LT50 range.

Crowns, drives and brackets that fit

The motor reaches the tube through a crown and drive set, and the set has to match the tube profile you ordered. For a 2.5 inch round tube, the Somfy LT50 2.5" Round Crown and Drive Set (9012231) carries the motor head end and transfers torque to the tube wall. For a 70 mm octagonal shutter tube, the Somfy Octagonal LT50 70mm Crown and Drive Set (9012234) does the same work on the eight-sided profile that European style shutter boxes use. Snap-on drive wheels cut assembly time, and a drive stop with its screw locks the drive to the tube so the motor cannot walk.

Mounting goes through the Somfy LT50 Star Head Motor Bracket (9410651). The star head drops into the bracket recess and a clip retains it. Somfy rates that bracket to 50 Nm, which clears the 535A2 with margin. Keep the bracket square to the tube axis. A bracket that sits out of line loads the drive wheel on one edge and shortens its service life.

Four wires, one switch or relay

Standard 4-wire control gives you line, neutral, up and down. A wired rocker switch or a dry contact relay output from a building control system drives the two directional conductors. Somfy fits the cable as a detachable SJTW lead at the motor head, so an installer swaps a damaged cable or changes its length without pulling the motor out of the tube. Interlocked contacts matter on an AC tubular motor. Energizing both directions at once stresses the winding, so pick a switch or a relay card that blocks that condition.

Pre-construction jobs favor this motor. Crews run the cable while the walls stay open, then hang the shutter or awning later in the schedule. Wired control also costs nothing at rest, and Somfy rates the 535A2 at zero standby draw.

Limits, head positions and install notes

Push buttons on the motor head set the upper and lower stop points. An installer holds the direction button, drives the tube to the position wanted, and stores it. The head mounts in six orientations, which lets a crew point the cable exit away from the wall or the fascia inside a tight box. Somfy rates the motor at 250 W during travel, and a 15 amp branch circuit carries several of these on separate switch legs.

Confirm torque against the finished assembly before you commit the order. A shutter curtain gains weight with every slat, and an awning gains it with arm hardware and a valance. Builders step up a size when the calculated load lands close to 35 Nm, which is the point where the LT50 range hands off to the larger LT60 motors Somfy builds for heavy shutters.

Common questions about the Somfy 535A2

What tube does the Somfy 535A2 fit?

It needs a tube with at least 1.85 inches of clear inside diameter. A 2.5 inch round tube takes the 9012231 crown and drive set, and a 70 mm octagonal shutter tube takes the 9012234 set. Measure the inside diameter at the motor end before ordering, since an internal weld seam can cut into the clearance you expect.

How much torque does the 535A2 produce?

Somfy rates it at 35 Nm, 310 inch-pounds, at 20 rpm. That output covers medium to heavy rolling shutter curtains and folding arm awnings. Total the slat or fabric weight plus the arm hardware, then compare the result against the rating before you order the motor.

Which bracket works with the star head?

The LT50 Star Head Motor Bracket (9410651) accepts the star head and retains it with a clip. Somfy rates that bracket to 50 Nm, above the 35 Nm this motor produces. Mount it square to the tube axis so the drive wheel loads across its full face.

Can a remote control this motor?

The 535A2 takes wired control through its four conductors. An RTS receiver wired between the switch leg and the motor adds remote control to a wired circuit. Somfy also builds the 535A2 RTS CMO and the Altus RTS 535A2 for jobs that start from radio control, and either one saves the receiver on a new install.

Order the Somfy 535A2 120V 4-Wire Motor (1047368) together with the crown and drive set that matches your tube profile, and add the star head bracket in the same order so the install does not stall waiting on parts. Somfy backs the motor with a 5 year warranty.

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