The most common arrangement, which is used with only minor variations from small drives of say 0.5 kW up to the largest industrial drives of several megawatts, is the so-called two-loop control. This ...

This is the second half of a two-part article discussing principles and application of the AC induction motors that provide motive power for most of the equipment HVACR engineers specify. In March, we ...

The topic of motors and motor control techniques is wide and varied. Part one of this two-part article will cover the principles of alternating-current (AC) motor operation and control. Part two will ...

Article 430, Part XI provides the NEC requirements for motors more than 1,000V. Why this special category? Because there are additional hazards due to the higher voltages [430.221]. Part XI does not ...

Motors and their associated equipment must be protected against both overload and overcurrent (short circuit or ground fault). This function is usually split, with ...