Water Pump System Upgrades Webinar: Follow-Up Q&A


These are the questions and answers from the session following the Baldor-sponsored Pumps & Systems webinar "Water Pump System Upgrades: An innovative high horsepower / low speed solution," which took place on July 24, 2014.

Q. Is this assembly suitable for wet well applications? Can you give us some detail to describe its use in these types of installations?

A. No, this assembly is not suitable for wet well applications. At 10-plus feet tall and multiple ten thousand pounds depending on application, it is designed to replace large synchronous motor applications. It is designed to be housed in pump stations with engineered foundations.

Q. Can I use the clutch as a variable speed control?

A. The Vertical Gearmotor (VGM) with clutch is not designed to be a variable speed device under normal circumstances other than slow speeds during start up that can extend several minutes. Although a heat exchanger could be designed to dissipate the heat from operation at less than 100% speed during normal operation, this would not be an energy-sufficient solution. If variable speed operation other than start up is required for extended periods, a VFD is normally a better solution.

Q. Can you tell us the change in pump efficiency that resulted from one or more of your actual case studies?

A. Actual testing is still ensuing, so we do not have actual case studies at this time.

Q. If you use a VFD, would the VFD be smaller?

A. The VFD would still have to be matched to the motor horsepower.

Q. Is the gear motor primarily targeted for existing applications or new installations?

A. The vertical gear motor (VGM) is targeted to both new and existing applications. For existing applications where high maintenance, operating costs and overall unreliability from ineffective pump motor matching exists, the VGM can be retrofitted to your application. For new installations, where system matching to the pump's best efficiency point, as well as design and civil engineering costs, are issues, the VGM is an effective solution that also offers the advantage of smaller support structures and facility enclosures.

Q. Can you estimate the saving achieved by this solution in your applications so far. That is vs. high pole count motors to achieve the slow speed.

A. The savings will be quantified by engineering analysis of each unique application.

Q. What is the percentage cost increase, roughly, for adding the CST option? How much time is involved in installation?

A. Adding clutches is very dependent on the size unit and the application requirements but would generally add approximately 15% to 25% to the price of the gearmotor. It should be noted that in addition to the other advantages afforded by the clutches, this would eliminate the need for the expense of a VFD drive, if one is needed for start up operation. As previously stated, if variable speed operation for other than start up is required and for extended periods, a VFD is normally a better solution. Also, if the pump start-up torque is unusually high at low speeds (for priming), the clutch can be used as a “soft start” which alleviates the need for a custom motor, which can be very expensive and require long lead times.

Q. How is the power factor improvement achieved?

A. The improvement in power factor (PF) results from utilization of a low pole count induction motor, which by nature has a higher PF than a high pole count induction motor. Utilization of gearing to reduce the speed does not lower the power factor; however lowering the base motor speed by increasing the number of poles in the motor will decrease the power factor.

Q. What are the routine maintenance requirements for the gearbox?

A. Lubrication oil should be sampled and/or changed periodically based on application specifics. Without a sampling, system oil changes are recommended at 6 to 12 month intervals. Use of an optional oil filter system and sampling program can greatly extend these intervals.

Q. What is the typical lead time for the various sizes?

A. Gear motors are designed to provide the required output speed for specific operation. Therefore, approximately 3 weeks should be allowed for completion of specific gear ratio design after confirmation of final desired output speed. The normal lead time for completion of ratio design and manufacture can be considered to be approximately 30 weeks.

Q. Where is it designed and built?

A. The gear motor is designed by Baldor’s Dodge product engineering team. Baldor has more than 60 years of experience in designing and manufacturing innovative gear products under the Dodge brand. Gearmotors are manufactured in Dodge product facilities located in Stratford, Ontario, Canada and Shanghai, China.

Q. Is supplemental cooling required for the gearmotor with clutch? Is this achieved? If so, how?

A. Supplemental coding is dependent on the specific application requirements. If needed, coding would normally be accomplished through utilization of an air-to-oil or water-to-oil heat exchanger.

Q. With regard to the CST electronic control, how does this differ from other kinds of monitoring technology? Can it be used with other kinds of equipment, or is it specific to this product?

A. The Controlled Start Transmission (CST) is controlled by a standard PLC with programming specific to the VGM. The standard offering would be ABB control. The ABB PLC system can interface with other systems where needed; however, other manufacturers' controls can be used, if specified.

For any questions or to request additional information from Baldor, please contact Allison M. Carroll, at allison.carroll@baldor.abb.com or 704-780-9536.

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See also:

Upstream Pumping Solutions

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