Comparison of motor speed control methods

It is often desirable to control the motor speed, usually for reasons process control for such variables as flow or pressure. Such applications as fans and pumps often have varying… Read more

Mar 13, 2015 | Edvard

The most common LV/MV motor starting devices

The most common motor starting device is the low voltage motor-starting contactor. A contactor is defined as “a two-state ON-OFF device for repeatedly establishing and interrupting an electric power circuit.” Contactors are… Read more

Jan 14, 2015 | Edvard

4 Types of DC Motors and Their Characteristics

As you already know, there are two electrical elements of a DC motor, the field windings and the armature.The armature windings are made up of current carrying conductors that terminate… Read more

Jan 07, 2015 | Edvard

When to Buy Premium Efficiency Motors?

Using premium efficiency motors can reduce your operating costs in several ways. Not only does saving energy reduce your monthly electrical bill, it can postpone or eliminate the need to expand the electrical… Read more

Dec 31, 2014 | Edvard

8 NEC Basic Feeder Circuit Sizing Requirements

Once the branch circuit loads are calculated, the feeder circuit loads may be calculated by applying demand factors to the branch circuit loads. General Lighting Loads (Article 220.42) Show window… Read more

Dec 17, 2014 | Edvard

PLC Implementation Of Forward/Reverse Motor Circuit With Interlocking

Figure 1 illustrates a hardwired forward/reverse motor circuit with electrical and push button interlockings. Figure 2 shows the simplified wiring diagram for this motor. The PLC implementation of this circuit… Read more

Dec 10, 2014 | Edvard

Characteristics And Work Principles of Switched Reluctance (SR) Motor

The Switched Reluctance (SR) motor is very different from the other polyphase machines described because both the stator and the rotor have salient poles. The motor can only be used… Read more

Dec 08, 2014 | Edvard

14 energy-efficiency improvement opportunities in pumping systems

Pump systems consist of pumps, driver, pipe installation and controls (such as ASDs or throttles) and are a part of the overall motor system. Below some of the energy efficiency… Read more

Oct 13, 2014 | Edvard

Energy Efficiency Aspects of Electric Motors

Three-phase squirrel-cage induction motors comprise a considerable percentage of the electrical load in the United States. Design, operation, and maintenance of these machines is well described in some of the… Read more

Oct 01, 2014 | Edvard

8 Energy-Efficiency Improvement Opportunities In Electric Motors

When considering energy-efficiency improvements to a facility’s motor systems, a systems approach incorporating pumps, compressors, and fans must be used in order to attain optimal savings and performance. In the… Read more

Sep 29, 2014 | Edvard

13 features and advances of using electronic soft starters for a motor starting

Soft starters serve for a continuous adjustment of the starting characteristic of three-phase asynchronous motors to the requirements of the load by controlling the voltage across the motor and enable… Read more

Jul 14, 2014 | Edvard

Selecting AC induction motors for cement plant applications

This technical article relies on the great paper written by Barton J. Sauer (Siemens Energy & Automation) which goes into essence of selecting the proper AC motor for cement plant… Read more

Jun 18, 2014 | Edvard

How to measure insulation resistance of a motor

If the motor is not put into operation immediately upon arrival, it is important to protect it against external factors like moisture, high temperature and impurities in order to avoid… Read more

Jun 09, 2014 | Edvard

PLC application for reduced voltage-start motor control

Figure 1 shown below illustrates the control circuit and wiring diagram of a 65% tapped, autotransformer, reduced-voltage-start motor control circuit. This reduced voltage start minimizes the inrush current at the start… Read more

Jun 04, 2014 | Edvard

Motor Starting via Chokes or Resistors

The series-connected chokes (Figure 1) or resistors (Figure 2) reduce the voltage at the motor and hence also the starting current. The starting torque is reduced by around the square… Read more

Mar 07, 2014 | Edvard