Pumps & Systems, August 2007

Even when a redundant pumping system is in place, it can be advisable to monitor the condition of the operating units in critical applications where maintaining production depends on motor-pump reliability.

Pumps & Systems, August 2007

With the wide use of variable frequency drives in the pump industry and increasing unit size, it is becoming more difficult to design mechanical systems free from natural frequencies within operating speed range. If such an occurrence is allowed in the field, a resulting resonance condition threatens to significantly impact performance and longevity of the equipment.

You have probably noticed that there are several camps out there when it comes to centrifugal pump applications involving variable frequency drives (VFDs). One group believes that every pump should have one, while another thinks that they should be banned altogether. And, of course, there is the middle ground that says it depends upon the pump and application.

Pumps & Systems, June 2008

While driving a car with the gas pedal to the floor and then controlling your speed using the brake is obviously inefficient, many facilities use the approach for pump control. Flow control with throt­tling or restrictive devices sacrifices energy efficiency and results in unnecessary costs. However, with an understanding of basic principles, an analysis of the specific application, information about available control solutions and evaluation of technologically advanced equipment, facilities can make a quantum leap in improving the efficiency and econ­omy of pumping operations.

Pumps & Systems, June 2008

Traditionally, the primary use of drives has been in applications such as powering pumps, fans and conveyors. While they will continue to be used in these applications, today's end-users have a different approach from that of a decade ago.

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 tests that can troubleshoot motors, drives and associ­ated electrical panels and prolong their operational lifetime. Ther­mal imagers can detect potential problems and insulation resistance and electrical tests can deter­mine the cause.

Pumps & Systems, September 2008

Why is "run to fail" a common operational strategy at water/wastewater organizations? Explore this phenomenon and other results from a maintenance methodology survey.

Pumps & Systems, September 2008

The 4-20mA Current Loop

The 4-20mA current loop is used to transmit analog data representing various process variables like level, pressure, temperature or flow. Although conceptually simple, a 4-20mA current loop can be tricky to troubleshoot. Current flows in a single direction through each device in the loop (see Figure 1).

Pumps & Systems, September 2008

Wireless technology has significantly impacted business worldwide. It enables a greater degree of connectivity among devices for enhanced monitoring and utilization of existing assets. It has also led to the development of new applications that improve productivity, uptime and overall business performance.

Pumps & Systems, September 2008

Explore best practices for securing SCADA systems in remote sites. This article addresses threats and corresponding implementation measures with a focus on SCADA RTU installations and the processes they monitor and control.