Pumps & Systems, October 2007

With highly reliable electrical systems, protective relays may be called upon to operate very infrequently. However, the effects of faults and abnormal conditions can be severe and protective relay systems must be designed carefully to protect against the worst possible fault conditions.

This article briefly describes the basic goals and philosophies behind relay system design and the types of protection that are applied in water and wastewater treatment facilities. As motors for pumping applications are particularly critical to water and wastewater facility operations, the major faults and abnormal conditions that affect motors are also covered. The relay schemes discussed here are typically applied to systems with operating voltages greater than 1000-V.

Pumps & Systems, April 2008

Production, distribution and refining applications in the oil and gas industry rely heavily on motor-driven pumps and pumping systems. Keeping electric motors driving critical operations at peak performance is vital to ensure maximum profitability.

Pumps & Systems, April 2008

In the oil and gas industry, electric submersible pump (ESP) systems are probably best known as an effective artificial lift method of pumping production fluids to the surface. ESPs are especially effective in wells with low bottomhole pressure, low gas/oil ratio, low bubblepoint, high water cut or low API gravity fluids.

Pumps & Systems, April 2008

Artificial lift technology selection is highly dependent on the conditions of the wellbore and the specific application parameters of a given well. Electrical submersible pumping (ESP) systems employing centrifugal pumps are the preferred artificial lift technology for wells with higher flow rates and deeper well depths. ESP systems are used to lift fluids for a variety of industries, including oil and gas, mining, municipal water and geothermal. Rod lift systems-the most common form of artificial lift-use sucker rods to bring fluid to the surface and are used primarily in lower flow wells. 

Pumps & Systems, June 2007

Most of the electric motor information we use on a daily basis is pretty straightforward. Voltage, amps, efficiency, and service factor are all well understood terms in our industry. There is, however, one motor characteristic that can be anything but straightforward. That characteristic is power factor (PF).

Pumps & Systems, June 2007

Shaft failures do not happen everyday, but when they do, it can be a challenge to determine the cause of failure. Here's a technical explanation of what happens when the shaft bends or breaks.

Named for a technique commonly used on failing pumps, "percussion maintenance" - where a technician beats on the pump's stalled motor with a hammer or rubber mallet - often indicates motor deficiencies in his diaphragm pump. Though it is impossible for the maintenance department to predict when a pump will stall, such maintenance techniques are often the result of poor motor design.

Pumps & Systems, June 2007

When a motor fails, users can (1) rewind, possibly for high efficiency; (2) replace the failed motor with a new motor; or (3) invest in a premium efficiency product. Here are the advantages and disadvantages of each approach and the precautions that must be taken to assure the best investment.

Pumps & Systems, June 2007

In many pump installations, problems such as jams and suction loss can lead to serious damage to the motor or pump long before the thermal overloads trip. These problems can be quickly detected by monitoring drive motor current.

Pumps & Systems, June 2007

Why integrating vibration monitors with process controls provides fast response to pump faults, adds predictability and avoids unexpected shutdowns.