AC And DC Motors Reviews

In the late 90's, Lutron introduced the QED (Quiet Electronic Drive) which it paired with its own brand of shades (roller shades mostly). The product made big waves for being practically noiseless. This was a classic example of redefining the parameters of competition in an industry. Beforethe advent of Lutron's quiet motors, consumers did not even know that motor noise level was or would become a factor in their motorized shade purchase decisions. Only in the last couple of years has Somfy caught up to the QED's noiselessness. Today, there is still a difference, but it is slight and most consumers do not consider it a deciding factor.

Somfy manufactures two different types of 'quiet' motors used in motorized window shades; an AC powered version (ST50) and a more recently introduced DC powered version (ST30). Lutron's QED Motors are all low voltage, DC Motors. The difference between AC and DC power is that the former is high voltage while the latter is low voltage. AC Power is the same as the power received from plugging a cord into a standard wall outlet. Low voltage is powered by that same outlet but the cord has a transformer (think of a cell phone cord or a computer power cord with their boxes on the plug on in the middle of a cord - that is a transformer) and reducing or 'knocking down' the high voltage power received from the outlet to low voltage power. A main reason that DC power is important is that fewer building code issues arise and no electrician is required for wiring low voltage powered motorized window shades. Absent an electrician, wiring costs and job complexity are both considerably reduced.

The QED is available in three different sizes called the QED64, QED100 and QED225. The number gives a rough gauge of the square footage of fabric that the motor is designed to lift. For example, the QED64 can lift a shade up to 8 feet x 8 feet, the QED100 can lift a shade up to 10 feet x 10 feet and the QED225 can lift a shade up to 15' x 15' - this size motor is only very rarely required for residential applications. These are approximations only, in the field, these motors are known to actually lift more than these numeric values imply. The size of the motor affects its diameter which determines the diameter of the tube that the motor uses. Lutron's QED64 uses a 1 5/8" tube, the 100 uses a 2 ½" tube and the larger 225 uses a 3 1/2" tube. Tube diameter is important mostly for determining how wide motorized shades can be without bending (deflection). A bent tube means that fabric will not roll up properly. The fabric will sag causing creases- this is not acceptable. Therefore motor size is as much about shade width as it is about lifting capacity.

Somfy's quiet motors, known as the Sonnesse line, also use different tube sizes. The ST30 uses a 1 1/2" tube, the ST50 can use either a 2" or 2 1/2" tube*. The lifting capacity of the ST50 falls somewhere between the 100 and 225. For very large applications, Somfy has larger motors, but to date, they are not in the Sonnesse (quiet) product line. It is very rare that a motor larger than an ST50 is needed for interior applications. This is true even if multiple shades are driven by a single motor.

Both the QED and Sonnesse motors have proven to be reliable and both come with 5 year warranties.