The correct answer is: d) excessive heating due to motor overloads and failure to start You'll find the rules for motor and branch-circuit overload protection in Part III of Art. 430 in the 2011 NEC.

When you get the call, “The motor won’t start,” you’d best have a logical and systematic plan in place to approach the problem. “Easter egging” just doesn’t work unless you happen to be very lucky!

For the PDF version of this article, click here. Motor controllers used to power, stop and control the speed of a variety of motors must deal with a wide variety of surges due to switching events.

An overload or short circuit in a fuse or mini circuit breaker can lead to undersupply or failure of an entire 24-V dc power-supply system. Selectivity protection using an electronic fuse offers a ...

Safety is a major concern in a good many motor-driven applications. This is true in industrial applications where motion starts when power is applied and especially true when power is restored after ...

This is a simple and very effective project circuit which helps to control the speed of a DC motor using pwm and microcontroller. In many applications, it is important to control the speed of DC motor ...

Guest columnist Alfred Hesener, European marketing director at Fairchild Semiconductor, describes how good design of power switches can help reduce losses in motor control circuits. Energy-saving ...