Programming and controls · Rolling Shutter Guide
How do I set the limits on a Somfy manual-override shutter motor?
A Somfy manual-override motor keeps its limits on two spring-loaded push-buttons, one white and one yellow, on the motor head at the motor end of the shutter box. Push both in to clear the limits, run the curtain to each stopping point and release a button there, testing which button holds which limit.
Key facts
- The two limit push-buttons are spring-loaded: pushed in, a button locks down and that limit is off, so the motor keeps running; released, it pops out and sets the limit where the curtain is. Roll-A-Shield data
- If the buttons face the back wall of the box you will see two short metal prongs marked Y and W instead; pull a prong toward you to press or release its button. Roll-A-Shield data
- Somfy ties the colors to the side the curtain comes down from, looking at the motor head end-on: down on the right, yellow sets the lower limit and white the upper; down on the left, the reverse.
- Roll-A-Shield presets the limits when the shutter is built; in rare cases they drift or zero themselves in shipping, and then they need to be set again. Roll-A-Shield data
- Manual-override motors have no obstacle detection; only the limit you set stops the curtain at the bottom. Roll-A-Shield data
Applies to: Somfy manual-override (CMO) tubular motors with white and yellow limit push-buttons: the wired Altus CMO on a wall switch and the radio Altus RTS CMO on a remote, including on Roll-A-Shield shutters. Gaposa override motors use limit screws instead; see the link below.
Why can't I set the limits from the remote?
Because on a Somfy manual-override motor the limits are mechanical push-buttons on the motor head, not settings stored by the remote. Roll-A-Shield's override overview gives up remote limit-setting as one of the trade-offs of choosing an override motor. The same two buttons are on the wired version (run from a wall switch) and the radio version (run from a Somfy remote); in both cases you drive the curtain with the switch or remote and set the limits at the motor.
Roll-A-Shield sets these limits when the shutter is built. Its install guide notes that in rare cases they drift or "zero" themselves in shipping and then have to be set again.
Where are the white and yellow buttons?
On the motor head, at whichever end of the shutter box holds the motor. Roll-A-Shield's guides check and set the limits with the box cover off.
- Two round buttons, one white and one yellow: the buttons face you. Press them with a long thin screwdriver.
- Two short metal prongs marked Y and W: the buttons face the back wall of the box. Pull a prong toward you to press or release its button.
Somfy's own guide describes optional adjustment pull tabs for working the buttons where they cannot be reached, and a protective housing for the motor head that is refitted only in some mounting positions.
What a button does: pushed in, it locks down and switches that limit off, so the motor keeps running in that direction. Released, it pops out and fixes the limit where the curtain is at that moment.
Which button is the upper limit and which the lower?
It depends on which way the curtain comes off the tube, so the same color does different jobs on different shutters.
| Looking at the motor head end-on, the curtain comes down… | Lower limit | Upper limit |
|---|---|---|
| on the right | Yellow | White |
| on the left | White | Yellow |
Roll-A-Shield's install guide does not rely on the colors. It finds out by testing, as in the steps below: release one button at the top, then try to lower the curtain.
How do I set the upper limit?
Tools: a long thin screwdriver (or your fingers for prongs), the wall switch or a paired Somfy remote, and a helper to watch the curtain.
- Push in both buttons (or pull both prongs). There is now no limit at all, so be ready to stop the motor with the switch or remote.
- Raise the curtain to where it should stop at the top.
- Release one button: press it again with the screwdriver, or pull its prong again.
- Try to lower the curtain.
- It moves down: that button set the upper limit. Go on to the lower limit.
- It will not move down: that button set the lower limit at this height. Now you know which button is which; push it back in and repeat steps 2 and 3 with the other button.
- Move the curtain slightly off the limit and back to check it holds.
How do I set the lower limit?
- Make sure the lower-limit button is pushed in.
- Lower the curtain to where it should stop.
- Release the lower-limit button. It pops out and fixes the limit there.
- Move slightly off the limit and back to check it holds.
- Run the shutter all the way up and down and check it does not stick or hang up anywhere.
Stop: Manual-override motors have no obstacle detection. With a button pushed in nothing stops the curtain except you. Roll-A-Shield's guide uses two people the first time: one at the switch, one outside watching the shutter. Following a published Roll-A-Shield guide does not void the warranty. Mains wiring must be done by a licensed electrician.
Where should the curtain stop?
Roll-A-Shield's install guide gives the target positions for its shutters.
- Top: the bottom slat is still inside the guide rails.
- Bottom: the whole roll of slat is off the axle and the hanging straps have pushed the top slat toward the box.
- Too far down: if the slat starts to roll up the wrong way round the axle, stop the shutter at once and set the lower limit again.
If the curtain has already been driven past its limit and the top slats are bent, see a shutter that ran past its limit before running it again.
What if it still is not right?
| Symptom | Likely cause | Fix |
|---|---|---|
| Runs past the top or bottom and does not stop | That limit's button is still pushed in | Stop it, run back, and release the button at the right point |
| Will not move down at all after you released a button at the top | You set the lower limit at the top | Push that button back in; use the other button for the top |
| Stops a little short or a little long | Released slightly early or late | Push that limit's button in, move to the right point, release again |
| Stops working after several test runs | The motor's thermal protection tripped | Wait about 15 minutes and try again |
| No movement and no sound | No power or a remote problem, not the limits | See why a shutter won't go up or down |
What about the remote, the reset and the crank?
On the radio version, remotes pair the same way as on any Somfy RTS motor: hold the programming button on a remote that already works the shutter until the motor moves, then hold the programming button on the new remote until the motor jogs again. Somfy's radio reset for this motor erases paired controls, sensors and in-between positions; it does not list the push-button limits, but check them after a reset anyway. See how to reset a Somfy RTS motor.
The point of an override motor is the crank: Somfy says to switch off the power before cranking and never to run the shutter from a radio control while you are using the crank. More on how overrides work is on the manual override page. A Gaposa override motor sets its limits with two screws instead of buttons; see adjusting the limit screws or call (480) 921-0200.
Frequently asked questions
Can I set the limits of a Somfy override motor from the remote?
No. On a Somfy manual-override motor the limits are the two push-buttons on the motor head. The remote only drives the curtain while you set them.
Does resetting the motor's radio programming clear the push-button limits?
Somfy's reset for its radio override motor lists the paired controls, sensors and in-between positions as erased, not the push-button limits. Check both limits after any reset anyway.
Why does my shutter keep running past the bottom?
Either the lower-limit button is still pushed in, so there is no lower limit, or the limit was set too low. Stop the shutter at once and set the lower limit again. If the curtain has started to roll back up the wrong way round the axle, see the page on a shutter that ran past its limit.
Can I use the hand crank while the motor is powered?
Somfy says never to run the shutter from a radio control while using the emergency crank, and to switch off the power before cranking.
Parts and next step
Need a part or a hand?
Replacement motors, remotes, straps, slats and hardware ship from our Tempe, Arizona factory. Phoenix-area owners can book a service visit; everywhere else, our technicians help by phone. Call (480) 921-0200; the factory answers technical questions for any rolling shutter, not only ours.