Franklin Electric has always been pleased to offer you quality, state-of-the-art electronic products for all types of submersible pumping systems, including constant pressure systems. Our in-house electronics engineering team is continually working to make our products perform better, work smarter, and last longer. A key part of their effort is the feedback we receive from you about our products, and as a direct result of your observations, we are pleased to introduce the latest member of the CP Water family, SubDrive 75. We can honestly say YOU made it better.
SubDrive 75 is a variable frequency drive that changes the speed of the pump to satisfy demand in the system. Using a standard ¾ Hp pump mounted to a standard Franklin Electric 1½ Hp motor (3-phase, 230V), SubDrive 75 will drive the pump between 1800 and 4800 rpm to maintain constant pressure. An external pressure sensor is used to monitor the system pressure and provide a means for the installer to change the target pressure setting. Pressure setting options range from 25 to 80 psi.
A SubDrive 75 constant pressure system will provide performance consistent with a 1½ Hp pump curve. If the performance represented by the 1½ Hp curve of a particular pump series will satisfy your needs for head and flow, then the ¾ Hp pump in that series can be used to achieve the same performance when used with SubDrive 75.
It is important to remember that SubDrive 75 does not require a specially-designed pump. It utilizes a standard pump and motor, which allows you to use the pump brand of your choice to provide your customers with a dependable constant pressure system. For more information on the SubDrive 75, contact your pump supplier or call our Submersible Service Hotline at 800-348-2420.
4-Inch 10Hp Amp Readings
Over the past few years, Franklin’s 4-inch 10 Hp 460V motor has undergone some design changes that have caused the service factor (SF) amp values to change. These changes, in turn, have led to confusion in the field as to which value is correct. In reality, each value is correct, depending on when the motor was manufactured.
Older motors (models beginning with 234 329) had a service factor max amps rating of 18.5 A. However, when this motor was changed to a clad design (models beginning with 234 595), the SF max amps rating changed to 18.4 A. Then in July 2000, the new clad motor received a winding change to improve motor performance. Thus, the current production motor (models beginning with 234 595) carries a service factor max amps rating of 17.3 A.
The August 2000 edition of Franklin’s Application-Installation-Maintenance (AIM) Manual lists 18.5 A as the SF max amps rating for the 4-inch 10 Hp 460V motor. While this value was correct when the manual went to press, it does not properly represent 4-inch 10 Hp motors manufactured today and will be adjusted for the next edition of the AIM manual. Remember, however, a 10 Hp motor is still a 10 Hp motor, regardless of the service factor amp rating.