Motorised Blinds and Smart Curtains: Track Types, Motor Wiring, Hub Integration and Scene Automation

Summary

Motorised window treatments have shifted from a luxury specification to a standard smart home line item. The combination of energy monitoring, wake-up routines, and privacy automation drives the majority of installations — clients want blinds to open with the sunrise scene, close when the TV turns on, and respond to voice commands. Integrators who can specify and install the correct motor for each blind or curtain type, wire it correctly, and commission it through the smart home hub avoid the callbacks that follow mismatched specifications.

The motor selection is the step where most specification errors occur. The correct motor depends on the window treatment type (roller blind, Roman blind, Venetian blind, pleated blind, curtain track), the weight of the fabric, the tube or track dimensions, the available power source, and the hub integration protocol. A motor that's electrically perfect but physically incompatible with the blind tube, or that uses an incompatible RF protocol, becomes a warranty issue.

This article covers motor types, drive mechanisms, wiring approaches, hub integration for major protocols, and scene automation configuration.

Key Facts

• Tubular roller motor — most common type; inserts into hollow blind roller tube; available in 35 mm, 40 mm, 45 mm, and 50 mm tube diameters; specify correct tube diameter before ordering
• Motor torque — expressed in Nm; light voile 0.6–1.5 Nm; medium fabric 1.5–3.5 Nm; heavy blackout fabric 3.5–6 Nm; wider blinds and heavy fabrics require higher torque
• RTS (Radio Technology Somfy) — Somfy's proprietary 433.42 MHz one-way RF protocol; by far the most common UK residential motor protocol; requires Somfy Connexoon, TaHoma, or RTS-to-IP bridge for smart home integration
• RS485 (Somfy) — Somfy's two-way wired protocol for commercial and high-end residential; bidirectional status feedback; more expensive but provides confirmed position reporting
• io-homecontrol — two-way RF protocol at 868 MHz used by Somfy, Velux, and other European manufacturers; bidirectional status; integrates with more hubs natively than RTS
• Z-Wave motors — Fibaro FGR-223, Qubino Flush Shutter; Z-Wave modules that drive AC or DC motor outputs; universal application but require separate motor hardware
• Dooya/Zemismart — Chinese OEM motors widely used in budget roller and vertical blind systems; use proprietary RF at 433 MHz; Tuya/Smart Life app integration via Tuya hub; lower torque range
• Nice Motors — Nice (formerly GiGA Motors) produce tubular motors with Nicerf, TTBus, and Era One protocols; some supported natively in KNX systems
• Hardwired vs battery — hardwired motors require 240 V supply to each blind; battery motors (Somfy LI-ION range, Dooya T45i) eliminate wiring but require periodic recharging; hybrid solar-powered motors available
• Part P — 240 V motor wiring in dwellings is notifiable work; low-voltage (12/24 VDC) motor wiring fed from a driver is not notifiable
• Curtain track motors — separate category from blind motors; typically low-voltage (24 VDC) belt-drive or rod-drive mechanism; Somfy Irismo, Dooya DT52E, Silent Gliss 5100 are common UK specifications
• End limit setting — all motors require upper and lower travel limits to be programmed after installation; tubular motors have internal limit switches; set incorrectly, the motor will over-run or under-drive
• Obstacle detection — better tubular motors include current-monitoring obstacle detection that stops the motor if resistance is detected during travel; important for motorised skylight blinds where obstruction risk is higher

Quick Reference Table

Detailed Guidance

Motor Selection by Window Treatment Type

Roller blinds (single tube):

Measure the internal tube diameter precisely — 35 mm, 40 mm, 45 mm, or 50 mm. Most off-the-shelf roller blinds use 40 mm or 45 mm tubes. Insert the motor into the tube before the blind fabric is attached; the end cap on the drive side must match the bracket type supplied with the blind. Torque selection: for a 1.2 m wide blackout blind specify minimum 3.5 Nm; for a 3 m wide heavy blackout, 6 Nm or consider dual-motor operation if the manufacturer supports it.

Roman blinds:

Roman blinds use a cord-drive or rod-drive lift system rather than a rolling tube. The motorisation approach is either a motorised pulley unit that replaces the standard cord drive, or a separate micro-drive unit that winds the lift cords onto a motor-driven drum. Somfy Sonesse series and Nice Motors Low Noise range are suitable. The fabric weight is less critical than the number of lift cords and the mechanical efficiency of the cord routing.

Venetian (horizontal slatted) blinds:

Venetian blinds require separate motor channels for tilt (slat angle) and lift (raise/lower). Most motorised Venetian systems use a single motor that drives both functions sequentially — tilt is motor-driven, and a separate mechanism handles lift via a clutch or manual cord. Full motorised lift-and-tilt systems (Somfy SD40 dual motor) provide independent app control of both functions. Specify the blind head rail width and confirm motor compatibility before ordering.

Curtain tracks:

Curtain track motors are low-voltage (typically 24 VDC) and mount within the track header using a belt drive or rod-drive mechanism. Key specifications are:

• Track type — glider track, bay track, or motorised track; most motorised systems require a track designed for motorisation, not retrofit of a standard track
• Curtain weight — measured in kg total; most domestic motors handle up to 50 kg; heavy interlined curtains or long drops need commercial-grade motors
• Travel speed — 12–15 cm/s is typical; faster motors sound mechanical; confirm with the client whether quiet operation (silent Gliss) or cost is the priority

Skylight and roof window blinds:

Velux motorised blinds use io-homecontrol protocol natively and integrate with Velux Active (KIX 300 controller) or any hub supporting io-homecontrol. The Velux solar-powered option charges via a solar cell integrated into the blind; no wiring required. Useful for roof windows where cable routing is difficult.

Wiring: Hardwired 240 V Motors

A hardwired tubular motor requires a switched live to each motor — typically a 3-core + earth (brown, black, grey, green/yellow) or 3-core (live, neutral, earth) cable, depending on the motor's wiring requirement.

Wiring layout:

• Run 1.5 mm² or 2.5 mm² 3-core + earth cable from a spur on the ring main or from a dedicated motor circuit to the motor position
• Motor is connected: live (permanent) to neutral terminal, switched live to motor terminal (or L1/L2 for up/down direction control, depending on the motor type)
• The wall switch (if required) breaks only the switched live, not neutral
• For smart RF-controlled motors without a wall switch, the supply live runs directly to the motor; the motor responds to RF commands only — a standard 13 A fused spur provides the unswitched supply

Motor junction boxes: Most tubular motors terminate in a flying lead. Use a concealed junction box in the ceiling void or wall head, accessible for maintenance. IP rating requirements vary — bathroom roller blinds need motor junction boxes rated IP44 minimum.

Building Regulations Part P: Any new circuit or extension of a circuit to supply a 240 V motor in a dwelling is notifiable under Part P. This includes spur extensions from ring mains to motor positions. Either self-certify (if registered with a Competent Person Scheme) or notify the local building control authority.

Wiring: Low-Voltage DC Motors

Low-voltage curtain track motors and Venetian blind motors use 12 V or 24 VDC supply from a driver/transformer. The driver connects to a 240 V supply (Part P notifiable); the low-voltage secondary wiring to the motor is not notifiable.

Multi-drop wiring (RS485 / bus systems):

Somfy RS485, Nice TTBus, and Silent Gliss RS485 systems run motors in a bus topology — one cable daisy-chained to multiple motors, with each motor addressed individually. This simplifies wiring in large installations (a single cable run to 12 motors in one room is manageable) but requires compatible motor hardware. RS485 bus requires a bus master controller at one end and a 120 Ω termination resistor at the far end.

Hub Integration: Somfy TaHoma and RFXtrx

Somfy TaHoma Switch:

The TaHoma Switch is Somfy's local-plus-cloud hub. It receives Somfy RTS commands and translates them to/from IP. Home Assistant integration via the overkiz integration (built-in from HA 2022.2) provides:

• Open, close, stop, and position (%) commands for each motor
• Group scenes (e.g. "all blinds 50%")
• Real-time position feedback (io-homecontrol motors only; RTS is one-way, so position is estimated)

RFXtrx433E USB RF transceiver:

The RFXCOM RFXtrx433E is a USB RF transceiver that transmits and receives on 433 MHz and 433.42 MHz (RTS). Connected to a Home Assistant server via USB, it allows direct RF control of Somfy RTS motors without Somfy's cloud infrastructure. Setup involves:

1. Add the RFXtrx integration in Home Assistant
2. Pair each motor to the RFXtrx by putting the motor in programming mode (holding the Somfy remote button until motor jogs)
3. Transmit PROG command from RFXtrx; motor confirms with jog

Tuya/Smart Life (Dooya, Zemismart):

Tuya-protocol curtain track motors integrate with Home Assistant via the tuya integration or the local Tuya-Local integration (preferred for local control). Tuya-Local eliminates cloud dependency and works without internet. Pairing requires capturing the device's local key from the Tuya cloud platform — a one-time setup step.

Scene Automation Examples

Wake-up scene (sunrise):

Trigger: Time 07:00 (or sunrise offset -30 min)
Action:
  - Bedroom blinds → 0% (open)
  - Living room curtains → 100% (open)
  - Kitchen blind → 60%

TV mode scene:

Trigger: TV on (media player state = 'playing')
Condition: Time between 18:00 and 23:00
Action:
  - Living room blind → 100% (closed)
  - Living room curtain → 100% (closed)

Solar shading automation:

Trigger: Sun elevation > 30° AND sun azimuth between 150°–250° (south-facing)
Condition: Indoor temperature > 23°C
Action:
  - South-facing blinds → 70% (partial close for glare reduction)

These automations require the motor positions to be calibrated and confirmed — an io-homecontrol or RS485 motor reports actual position; an RTS motor tracks commanded position only.

Frequently Asked Questions

My client has 20 blinds — do I need to run a 240 V cable to each one?

Not necessarily. Battery-powered motors (Somfy LI-ION tube range, Dooya T45i) eliminate power wiring entirely. The client recharges each motor annually via USB or a proprietary charging lead. Battery life depends on use frequency — for a blind operated twice daily, typical battery life is 12–18 months. For a 20-blind install, battery motors reduce first-fix wiring time significantly. The trade-off is annual maintenance visits or client self-service for charging.

Can I retrofit motorisation to an existing roller blind?

Yes, if the blind tube diameter is standard (35–50 mm) and the motor fits. Remove the non-motorised end plug, slide in the tubular motor, fit the motor brackets (which differ from standard non-motorised brackets), reconnect the tube to the drive end, and set limits. Fabric and tube reuse is fine provided the tube isn't bent or damaged. Most Somfy LT motors are sold as kits with appropriate brackets.

What's the difference between Somfy RTS and io for a homeowner?

RTS is one-way — commands go to the motor, but the motor cannot report back its current position. If the smart home displays a percentage position, it's estimated from the travel time and calibration, not confirmed from the motor. io-homecontrol is two-way — the motor reports its actual position, so the app always shows the true state. For high-end smart home installations, io motors are worth the premium.

Do motorised blinds require planning permission in a listed building?

The blinds themselves are unlikely to need listed building consent, but any cable routing that involves making good to historic fabric may do. Internal works in listed buildings that affect the character of the building can require consent — consult the local planning authority before chasing cables through original plasterwork in a listed property.

Regulations & Standards

• Building Regulations Part P — notifiable electrical work in dwellings; 240 V motor circuits and driver supplies are within scope

• BS 7671:2018+A2:2022 (IET Wiring Regulations 18th Edition) — all motor circuit design and wiring

• BS EN 60335-1 — safety of household and similar electrical appliances; applies to blind motors as electrical appliances

• CE / UKCA marking — all motors must carry UKCA marking for UK market compliance; verify with supplier for post-Brexit imports

• GDPR UK — where smart blinds are controlled by presence detection or occupancy automation, data processing of location data may apply; advise homeowners

• Somfy RTS and io-homecontrol — proprietary Somfy protocols; technical documentation available to registered Somfy installers via Somfy Pro portal

• Somfy Pro Installer Portal — motor selection tool, protocol documentation, TaHoma integration guides

• RFXCOM RFXtrx433E Manual — RF transceiver setup and supported protocol documentation

• Home Assistant Overkiz Integration Documentation — TaHoma and Somfy hub integration

• IET Wiring Regulations BS 7671 — Chapter 55 (Other Equipment) — motor installation requirements

• Tuya Developer Platform — Local API Documentation — local key extraction for Tuya-Local integration

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