BLDC motor  s can be constructed in several different physical configurations: In the 'conventional' (also known as 'inrunner') configuration, the permanent magnets are mounted on the spinning armature (rotor.) Three stator windings surround the rotor. In the 'outrunner' configuration, the radial-relationship between the coils and magnets is reversed; the stator coils form the center (core) of the motor, while the permanent magnets spin on an overhanging rotor which surrounds the core. The flat type, used where there are space or shape limitations, uses stator and rotor plates, mounted face to face. Outrunners typically have more poles, set up in triplets to maintain the 3 groups of windings, and have a higher torque at low RPMs. In all BLDC motor  s, the stator-coils are stationary.

There are also two electrical configurations having to do with how the wires from the windings are connected to each other (not their physical shape or location). The delta winding connects the 3 groups of windings to each other in a triangle-like circuit, and power is applied at each of the connections. This pattern is typical to low-speed, low-torque motors. The wye ("Y"-shaped) winding, sometimes called a star winding, connects all of the windings to a central point and power is applied to the remaining end of each winding.

Although efficiency is greatly affected by the motor's construction, the wye winding is normally more efficient. At any given time, two-thirds of the windings in a delta configuration are running at half the voltage of the other, which is an impact on efficiency. The wye winding always powers only two windings in series, so higher voltages (or lower-resistance windings) can be used.

From a controller standpoint, the two styles of windings are treated exactly the same, although some less expensive controllers need to read voltage from the common center of the wye winding.