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...
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...
Pumps & Systems, September 2007 Because operational costs ride on efficiency determinations, accurate measurements of losses occurring within the motor are paramount. The reliability of...
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...
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...
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...
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...
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...
Facts and Fiction About Vibration
Facts can be tough—our emotions may get in the way. What we think we know is not always factual but is based on what we may intuitively feel is an undisputed truth. It is human to expect everyone...
Pumps and Systems, June 2009The pump industry is the largest purchaser of electric motors in the United States. According to the U.S. Department of Energy (DOE), electric motors consume more 50...
Pumps & Systems, June 2009The pump industry is the largest purchaser of electric motors in the United States. According to the U.S. Department of Energy (DOE), electric motors consume more 50...
Why integrating vibration monitors with process controls provides fast response to pump faults, adds predictability and avoids unexpected shutdowns.  Catastrophic damage to a 2250-hp motor...
A number of choices are available  when connecting pumps, fans and other rotating equipment to an electric motor. There are numerous mechanical and fluid coupling designs and, in some cases, a...
Measure Twice, Cut Once!
Aligning an electric motor coupled to a large air blower required multiple measurements.Around 18 years ago, a client needed assistance aligning an electric motor (more than 1,000 horsepower) coupled...
Pumps & Systems, November 2008Mechanical resonance occurs when an external source amplifies the vibration level of a mass or structure at its natural frequency. For a rotating mass like a motor or...
All electric motors (motors) have a housing that contains the working components of the motor. In the U.S., the enclosure describes this housing. The enclosure should meet specific environmental...
Pumps and Systems, February 2007All electric motors (motors) have a housing that contains the working components of the motor. In the U.S., the enclosure describes this housing. The enclosure should...