A zip screen fails in one of two ways. The fabric goes slack and ripples in the track, or the motor drives the hem bar into a chair someone left under the opening. The Somfy Maestria RTS 550R2 (1134095) answers both, and it does the job at 50 Nm, which is the top of the LT50 range.
Somfy lists the motor for exterior solar screens and retractable insect screens. Both are zip applications where the fabric edge rides in a side track, and both punish a motor that treats them like a roller shade.
Fourteen rpm is the point, not a compromise
Most LT50 motors run at 20 rpm or faster. This one runs at 14, and the slower speed is what lets a zipped fabric edge feed into the track without snatching.
Watch a zip screen close at speed and the failure mode is obvious. The hem bar arrives before the fabric edge has seated, the zipper pops out of the track partway down, and the owner calls it a fabric problem. A slower motor gives the edge time to engage over the full drop.
The tradeoff is honest. A twelve foot screen takes longer to close here than it would on a 20 rpm motor, and that is the trade Somfy made on purpose for this application.
Verified specifications
| Torque | 50 Nm (442 in-lb) |
| Speed | 14 rpm |
| Control | RTS, built-in receiver, 433.420 MHz |
| Channels | 12 |
| Radio range | 656.2 ft open field, rolling code |
| Power supply | 120V AC, 60 Hz, range 108V to 132V |
| Rated current | 2.1 A |
| Standby consumption | 0 W |
| Minimum tube inside diameter | 1.85 in |
| Head type | Star |
| Limits | Electronic, 250 turn capacity |
| Ingress rating | IP44 |
| Insulation class | Class I |
| Operating temperature | -4 F to 158 F |
| Thermal cutoff | 4 min |
| Warranty | 5 years |
Figures come from Somfy's published product record for 1134095. Somfy also publishes a 97.5 kg CO2 lifecycle footprint, which turns up on LEED and WELL documentation packages.
Obstacle detection earns its keep on a patio
The motor senses resistance on the way down and on the way up, and stops rather than pushing through it. A patio chair pulled under an opening after the schedule was set is the everyday case.
The same behavior protects the fabric. A screen that meets ice on the hem bar, or a track that has gone tight with grit, stops instead of tearing the zipper out of the edge. That turns a torn panel into a service call about a screen that would not close.
Fabric tensioning works the other way. The motor holds the panel stretched at the closed position, so a screen reads flat across the opening instead of showing the horizontal creases that follow a motor stopping short.
Two point one amps changes the circuit math
At 2.1 A this motor draws more than any other LT50 in the range. On a single screen that number disappears. On a patio with six screens closing together on a wind command, it is 12.6 A on one circuit, and a 15 A branch has almost nothing left.
Split the screens across circuits, or stagger them in the schedule so they do not all start in the same second. Standby draw is zero, so nothing accumulates between cycles.
Somfy publishes a 4 minute thermal time. A motor run continuously past that point protects itself and pauses to cool, which matters on a commissioning day when an installer cycles a bank of screens repeatedly.
Crown and drive by tube profile
The crown centers the motor in the tube and the drive hands rotation to the tube wall. Zip screen tubes come in several profiles, and the pair has to match the one in front of you.
A 70 mm octagonal tube takes the Somfy Octagonal LT50 70mm Crown and Drive Set (9012234). A 60 mm profile takes the Somfy Octagonal LT50 60MM Crown/Drive Set (9012233), and a deep-section 78 mm tube takes the Somfy LT50 DS78MM Crown and Drive Set (9012239).
At 50 Nm the drive carries real load. A drive one size off spins inside the tube after a season of full-width screens, and the symptom arrives as a screen that runs but no longer moves the fabric.
Brackets for a star head
The head is the LT50 star. The Somfy LT50 Star Head Motor Bracket (9410651) is the plate cut for it, and the Somfy LT50 Universal Bracket with Spring Clip (9420631) suits a retrofit where the motor has to clip into an existing cassette.
Order the bracket with the motor. Screen cassettes run tight, and a bracket that arrives a week later holds up an install that was otherwise ready.
Control and wind protection
The RTS receiver sits inside the motor, so power is the only run to the tube. The Somfy Telis 4 RTS Multi-Channel Patio Remote (1810645) sets limits at commissioning and covers four channels afterward, which suits a patio with several screens on separate openings.
Exterior screens want wind protection. The Somfy Eolis 3D WireFree RTS Wind Sensor (1816081) mounts on the hem bar and retracts the screen when the bar starts to move, and it pairs to the motor the same way a handheld does.
Adding a TaHoma hub later brings the app, sun and time schedules, and voice to the same motor without touching the screen hardware.
Ordering
Confirm the tube profile and its inside diameter against the 1.85 in minimum, then order the Maestria RTS 550R2 (1134095) with a crown and drive set matched to that profile, a star head bracket, one RTS transmitter, and a wind sensor. Check the branch circuit against 2.1 A per motor before a bank of screens goes on one breaker. Somfy covers the motor for 5 years.
Questions we get on this motor
What is the difference between the Maestria and the Altus RTS?
Both are LT50 motors with a built-in RTS receiver and a star head. The Altus RTS 525A2 is the general-purpose exterior motor at 25 Nm and 20 rpm. The Maestria 550R2 is built for zip screens, running slower at 14 rpm with obstacle detection and fabric tensioning, and carrying twice the torque at 50 Nm.
How wide a zip screen will 50 Nm cover?
Torque covers the load rather than a width, and on a zip screen the track friction matters as much as fabric weight. Fifty Nm is the top of Somfy's LT50 range and suits large exterior screens. The screen fabricator publishes a motor recommendation per frame size, and that figure outranks any general guidance.
Does obstacle detection replace a wind sensor?
No. Obstacle detection stops the motor when something blocks the screen's travel. A wind sensor retracts a screen that is already closed when the wind picks up, which is a different event. An exposed elevation wants both.
Can the Maestria run on a schedule?
Yes. A Somfy TaHoma hub brings sun and time schedules to RTS motors, and a Telis 1 Chronis RTS timer runs a daily schedule without a hub. Stagger the start times across a bank of screens so they do not all draw 2.1 A in the same second.
Shade Motors Direct is an authorized source for genuine Somfy motorized window shade, blind, and drapery parts.
