These questions were taken from viewers following Schneider Electric's "Pumping Controls and Systems" webinar on June 20, 2013.

I`ve read articles (some I believe in Pumps & Systems) about the energy and performance enhancement benefits of coating the interior and impeller of HSC pumps. I believe some of the articles have indicated increases in efficiency of 10 percent or greater. Do you have any experience or knowledge about that and whether it actually provides any benefit?

Coating the interior and impeller of centrifugal pumps has proven to make the pump more efficient. There are a number of articles available that discuss the improvements. Pumps and Systems has an article that provides a great overview of the benefits: https://www.pumpsandsystems.com/topics/benefits-pump-restoration-and-co…. It’s important to note that coating addresses the pump efficiency; however, the overall pump system efficiency must also be addressed.

  
Why do companies allow their pumps to run at 40 percent efficiency?

There are numerous answers to this question, so we’ll just name a few possible causes:

  • A basic answer is unfamiliarity with pumping applications and energy consumption – this is still a relatively new dynamic, especially in the US.
  • The priority around energy efficiency in the US is also relatively new. Applications such as lighting and HVAC have gained immediate attention, while pumping is on the rise.
  • Another factor is that pumps are used in many, if not most of all companies, but they seem to be well hidden many times, and do not have the visibility of other applications.
  • Pumps also tend to be frequently “oversized,” for a combination of both real needs and “conservative application.” Users are frequently unaware of this phenomena and the effect on energy efficiency.
  • Lastly, financial incentives, while commonplace, have not received great visibility and are sometimes considered difficult to attain. However, as their impact expands, so will systems to improve pump efficiency.

  
For pump optimization, at what point or points in the system should pressure head measurements be taken?

As discussed during the live webinar, it all depends on the application; however, to measure wire to water efficiencies, the head should be measured in conjunction with flow and kW for the pump or pump system for which you want to measure wire to water efficiency. Having these values measured dynamically allows for data that will help with pump optimization, and running a pump at the right time to meet operational needs, as well as reducing the cost of running the pump or pump system. This could also enable use of the right pump at the right time.
  
When should harmonic mitigation be of concern? Is there a typical horsepower that raises the concern of this occurring?

IEEE 519 gives requirements for harmonic mitigation at the Point of Common Coupling (PCC). IEEE 519’s PCC is where the electric service utility’s responsibility ends and the end user’s responsibility begins for electrical service. Some prefer to drive the PCC to different locations within a facility; a common point is at the line side of the drive terminals. This can increase the costs of harmonic mitigation significantly for the facility. Typically, harmonic mitigation should be a concern if the harmonics cause additional heating burden on conductors or interference with the operation of other electronic or electrical devices such as trip units, overloads, generators, automation equipment, etc. With a single application VFD, harmonics are typically looked at for pumps over 100 HP. However, harmonics could be an issue with multiple VFDs less than 100 HP on a system. A good application for an active harmonic mitigation device such as Schneider Electric’s Accusine is for a system with multiple VFDs. This allows the use of standard 6 Pulse VFDs to reduce the space and costs of the VFDs in the system.
  
For the same pump, is 4160 volts or 480 volts considered more efficient?

The voltage used to power the motor is not really driven by efficiency; it’s much more about power consumption – that is to say, current draw. Naturally, there are economic tradeoffs as well between capital investment and power consumption. For example, with a 4160 V system, cable conductor size is reduced for higher HP applications potentially reducing the wiring cost of the pump system. Other considerations include available power supplies, as 4160 volts are not always available at specific job sites. Additionally, considering one component of a pump system does not optimize efficiency. The complete system must be evaluated to determine the life cycle cost.

  
What is SCADA? What does it stand for?

SCADA is the acronym for Supervisory Control and Data Acquisition. The term SCADA usually refers to centralized systems which monitor and control entire sites, or complexes of systems spread out over large areas (anything from an industrial plant to a nation). Most control actions are performed automatically by Remote Telemetry Units (RTUs) or by Programmable Logic Controllers (PLCs). Host control functions are usually restricted to basic overriding or supervisory level intervention. For example, a PLC may control the flow of cooling water through part of an industrial process, but the SCADA system may allow operators to change the set points for the flow, and enable alarm conditions, such as loss of flow and high temperature, to be displayed and recorded. The feedback control loop passes through the RTU or PLC, while the SCADA system monitors the overall performance of the loop.
  
What are the major challenges in implementing energy upgrades for existing pumping applications and/or implementing energy optimized systems for new pumping installations? What are the trends for energy program investment incentives for pumping applications? What organizations are known to sponsor? What end markets are targeted?

Challenges for energy upgrades for existing pumps/optimizing new pumps:

  • Shifting the paradigm from just making the pump system work to making it work with the lowest life cycle cost - achieving more efficiency, reduced maintenance, and dynamic monitoring.
  • Looking at longer ROIs based on the life cycle of pump system – 3-5 year to 10-20 year or longer.
  • Right sizing pumps for present needs with the ability to expand easily for peak demands or future needs.
  • Designing pump systems with system efficiency as a key component of design approval.
  • Limited resources to accomplish energy savings projects.

Trends for incentive programs:

  • Electric utility incentives for pump efficiency and optimization
  • State and local incentives to reduce pumping energy
  • Federal incentives to reduce pumping energy. Example – ARRA had key energy components in legislation, 20% set aside for energy savings projects
  • Loans and grants for local, state and federal government as well as private investors offering same
  • Refer to DSIRE Website for energy savings programs by state: http://www.dsireusa.org/

Organizations known to sponsor:

End markets targeted:

  • Most end markets are targeted by energy savings programs.

How does the "intelligent system" approach—measure/fix/automate/monitor—best encouraged all industries with pumping applications? What type of support is needed by pump manufacturers and pump users to take advantage of the new trends, such as remote monitoring?

The “intelligent system approach provides a closed loop system to measure and monitor energy consumption on an ongoing basis. Hence, setting a baseline for optimal operation and measuring/correcting any deviations that may occur due to system dynamics, pump wear, etc. See Slides 11-14 for details.
  
What are challenges faced by the water and wastewater industries to implement energy savings programs for pumping and all energy consuming loads?

The challenges are the same as what was stated for pumps and pump systems. In addition, producing the quality and quantity of water is a key concern to all operators of water and wastewater facilities. With public utilities, funding for projects is a major issue and design build at risk models using energy services performance contracting is an alternative method to implement energy projects. The energy savings pays for the improvements with a loan guarantee of the savings carried by an energy services company like Schneider Electric.
  
How much OSHA enforcement has taken place with NFPA70E in pumping markets, particularly in municipal water?

Municipal water authority enforcement has been at a low level and geographically spotty. This group of pumping customers is still in the learning process with the effects and requirements of NFPA70E. However, there are documented cases throughout the country where OSHA has cited water and wastewater facilities for incidents involving arc flash events or non-compliance with NFPA 70E. Based on this trend, as both awareness and new specifications which include arc resistant equipment gain momentum, we expect to see more incident energy studies, education and inspection (enforcement) take place at municipal water facilities.
  
Where can I find additional information about what was covered during today's webinar?

Schneider Electric offers some focused resources on our website including:

In addition to these resources, and the organizations mentioned above, the following organizations may have useful information to enhance today’ presentation: