Somfy 550R2 RTS CMO Motor Fit, Torque and Crank Guide

Installers reach for the Somfy 550R2 RTS CMO when a rolling shutter or an awning outgrows the smaller LT50 motors and the owner still wants a hand crank for outage days. Somfy builds this reference at 50 Nm and 14 rpm, puts an RTS receiver inside the motor, and fits a compact manual override on the head. The head is the detail that decides your bracket order, and it catches people out.

Torque and tube size come first

Somfy rates the 550R2 RTS CMO (1051466) at 50 Nm, which converts to 440.1 in-lb, running at 14 rpm. That pairing suits wide rolling shutters and heavy awning fabrics where the travel is long and the load does not let up. Somfy's official designation for the reference reads 550R2 RTS CMO 50/14SJTW 10FT U, so the torque and the speed sit in the part name.

The motor body measures 1.97 in across and 30.98 in long. Somfy publishes a minimum internal tube diameter of 1.85 in. Measure the inside of the tube, not the outside. A 2 in outside tube with thick wall can fall under that 1.85 in figure, and the motor will not enter.

Applications Somfy names for this motor

Somfy's product record for reference 1051466 lists two applications: awning and rolling shutter. The IP 44 rating and the -13 to 158 F operating range back that up, since both jobs put the motor near an exterior wall or inside a shutter box that sees weather. Somfy assigns the motor protection Class I, which means the installer lands the ground conductor.

Exterior solar screens and zip screens sit outside the applications Somfy names here. Somfy builds the Maestria line for screen work, and the Sunea line for cassette awnings with a crank override. Match the motor to the application Somfy published for it, and the warranty conversation stays short.

Verified specifications

Every figure below comes from Somfy's published record for reference 1051466.

The CMO head changes your bracket order

Somfy publishes head type CMO for this reference. A CMO head carries the override gearbox and the crank eye at the front of the motor, and it has a different footprint from the LT50 star head. A star bracket will not hold it. Buyers who order LT50 star hardware out of habit end up sending it back.

Somfy's US part for this head is the Motor Bracket for Sunea CMO RTS US (9015802). The metric version carries part number 5061539. Both hold a CMO head with the crank eye clear of the bracket face, which is the point of the design.

Crown and drive selection follows the tube profile. For a 70mm octagonal tube, the Octagonal LT50 70mm Crown and Drive Set (9012234) seats the motor and transfers the 50 Nm into the tube wall. Confirm the tube profile before ordering, since an octagonal crown will not index a round tube.

RTS control with the receiver inside the motor

The receiver sits inside this motor, so no external RTS box goes in the shutter box or the awning hood. Somfy runs it at 433.420 MHz with 12 channels, rolling code encryption across 16 million possibilities, and 656.2 ft of open field range. Walls, foil-backed insulation and metal shutter boxes cut that figure, and Somfy's repeaters exist for exactly that.

A Situo 1 Channel RTS Pure Remote (1870571) covers a single opening. Larger jobs move to the Telis multi-channel remotes or a DecoFlex wall switch, and Somfy's TaHoma hub brings the motor into app control, schedules and voice. Somfy's RTS sun and wind sensors bind to the same receiver, which matters on an awning that needs to retract when the wind picks up.

Limits, power and install notes

Somfy publishes electronic limits on this reference with a 34 turn capacity. Set them from the remote with the RTS programming sequence rather than hunting for adjustment screws. The motor draws 2.1 A and 250 W while it runs, and it sits at 0 W in standby, so a circuit feeding several shutters needs the sum of the running loads.

The 9.84 ft SJTW cable detaches from the motor, which saves a fishing job when the shutter box sits far from the outlet. Somfy protects the motor for 5 minutes of continuous run before the thermal cutout drops in. Long shutter travel on a hot afternoon can reach that limit, and the motor resumes once it cools.

Somfy names no crank handle in the accessory list on this record. Match the override eye on the motor you receive to the crank you order, and check the eye thread against your existing hardware before you fit the awning.

Common questions about the 550R2 RTS CMO

Does the 550R2 RTS CMO need an external RTS receiver?

No. Somfy builds the RTS receiver into this motor. Pair a Somfy RTS remote or wall switch to the motor with the programming sequence, and the motor responds at 433.420 MHz across 12 channels. An external receiver adds nothing here.

What size tube does this motor fit?

Somfy publishes a minimum internal tube diameter of 1.85 in for reference 1051466. The motor body measures 1.97 in across and 30.98 in long. Check the tube inside diameter and the crown profile, since a 70mm octagonal tube and a round tube take different crown and drive sets.

Will an LT50 star head bracket hold this motor?

No. Somfy publishes head type CMO for this motor, and the CMO head needs a CMO bracket such as part 9015802 in the US pattern or 5061539 in metric. The crank eye sits at the front of the head, and a star bracket blocks it.

What does the crank override do during a power outage?

The compact manual override gives you a crank eye on the motor head. Fit a crank handle, turn it, and the shutter or awning moves with the power off. Somfy keeps the electronic limits intact through manual operation, so the motor returns to its set positions once power comes back.

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