The economic downturn has delivered a heavy blow to the industrial manufacturing sector in North America. Manufacturers are indicating sales drops of 30 percent to nearly 60 percent compared to that...
As a follow up on my AC Motors series, I thought it would be a good idea to provide a short overview of work, power and torque as it applies to the AC motor. I will provide a reference to a more in...
As a follow up on my AC Motors series, I thought it would be a good idea to provide a short overview of work, power and torque as it applies to the AC motor. I will provide a reference to a more in...
AC Motors Part 3-Single Phase Operation
It has been said that Washington, D.C., is the home of the largest invertebrate population in the U.S. This, of course, jokingly refers to the population of politicians and their lack of backbone or...
The frame sizes (physical dimensions) of AC motors have changed substantially through the years. Originally, they were considerably larger than those in use today. This increased size was the result...
The frame sizes (physical dimensions) of AC motors have changed substantially through the years. Originally, they were considerably larger than those in use today. This increased size was the result...
AC Motors Part 5: AC Motor Life
One of the major impacts on motor life is common sense—or maybe the lack thereof!It always amazes me how many open drip proof (ODP) motors are used in agricultural irrigation applications where...
AC Motors Part Two-Three Phase Operation
Although a number of AC motor designs are used, the induction motor is, by far, the most common and will be the topic of this column. We will also focus on the three-phase design as it provides a more...
AC Motors: Magnetism and the DC Motor
I received many comments on my four-part series on AC Power, and most of them were very positive. Several readers, however, thought they were too elementary. Ireminded them that the title of my column...
AC Power (Part Four): Transformers
Last of four partsLast month, we studied the properties and effects of resistive, inductive and capacitive loads in an AC circuit. This month, we will take self induction a step further and apply it...
AC Power (Part Three): AC Circuit Loads
AC Circuit LoadsLast month we discussed the relationship between voltage and frequency and tried to make that somewhat complex three phase sine wave a bit more understandable. This month we will...
AC Power Part 1: AC Versus DC
First of Three PartsThis three part primer is a basic introduction to AC power for those in the pump industry who need a place to start. It will also provide several web references to access if you...
AC Power Part Two: Voltage Versus Frequency and the Three Phase Curve
Last month, we ended with a discussion of the relationship between peak and RMS (or effective) voltage. We found that the RMS voltage will always be 0.707 that of peak voltage, and peak voltage will...
Calculating Energy Savings and Payback
Energy efficiency and reduced consumption are important issues in the pump and motor marketplace. Over the long term, electricity costs will continue to increase regardless of our actions. This will...
Back in the early seventies, when I was in grad school, our government pledged to convert the U.S. measurement system to the metric system. A popular cartoon at the time showed a lab technician with a...
Pumps & Systems, October 2007Back in the early seventies, when I was in grad school, our government pledged to convert the U.S. measurement system to the metric system. A popular cartoon at the...
Coupling Considerations for Pump Applications
A flexible coupling's primary functions are connecting two shafts, transmitting power from a driver shaft to a driven shaft and accommodating the misalignment between them. With only these...
Pump and Systems, June 2009 After spending money on a powerful new pump and the motor to run it, the next big decision is how to connect the two in a way that maximizes their efficiencies and...
Disc Couplings 101
Most of us probably never notice the spinning cylinder mounted between the pump and motor, except how easy it is to dis/assemble when a pump or motor is changed out. Otherwise, the disc coupling never...
Pumps & Systems, September 2007 Because operational costs ride on efficiency determinations, accurate measurements of losses occurring within the motor are paramount. The reliability of...
Because operational costs ride on efficiency determinations, accurate measurements of losses occurring within the motor are paramount. The reliability of efficiency data is key to any energy-savings...
Electric Motor Efficiency Regulations Part One
Integral Hp AC motors Between 1-500 hpThe Energy Independence and Security Act of 2007 (EISA), which restates and broadens the definition of General Purpose Electric Motors, goes into effect on...
Electric Motor Efficiency Regulations Part Two
What pump manufacturers and pump users need to know about small electric motor regulations. Second of Two Parts.Part One of this two-part article discussed Integral HP AC Motors from 1 to 500 hp...
Electric Motors: Driving to Higher Efficiency
The freefall in electric motor sales is a direct effect of the worldwide economic downturn, which has severely depressed industrial and commercial productions. Despite the 20 to 30 percent drop in...
Pumps & Systems, June 2008 Due to the expense and labor required, most facilities need to maximize the life of their motors. Electrical, insulation resistance and thermal measurement are three...
Due to the expense and labor required, most facilities need to maximize the life of their motors. Electrical, insulation resistance and thermal measurement are three tests that can troubleshoot...
Explosion Proof Couplings
Mechanically generated sparks, electrostatic discharge and high surface temperatures are all potential ignition sources in explosive atmospheres. Flexible couplings play a significant role in creating...
Following the development of variable frequency converter drives during the 1990s, totally enclosed fan-cooled (TEFC) AC induction motors became viable options for replacing DC motors in pumping...
Pumps & Systems, June 2008Following the development of variable frequency converter drives during the 1990s, totally enclosed fan-cooled (TEFC) AC induction motors became viable options for...
An argument in favor of IEEE-841's provision for motor bearing protection.In June, 2007, a reader asked Electrical Apparatus magazine, "How long should motor bearings last?" The answer will astound...