Last month, we ended with a discussion of the relationship between peak and RMS (or effective) voltage. We found that the RMS voltage will always be 0.707 that of peak voltage, and peak voltage will always be 1.414 that of RMS voltage. This relationship holds true regardless of the sine wave frequency. But, as frequency changes, the total voltage applied to a circuit per cycle can differ substantially. To visualize this difference, we will need to introduce another unit of measure-volts per hertz.

Integral Hp AC motors Between 1-500 hp

The Energy Independence and Security Act of 2007 (EISA), which restates and broadens the definition of General Purpose Electric Motors, goes into effect on December 19, 2010. Certain motors "manufactured (alone or as a component of another piece of equipment)" will be required to have nominal full load efficiencies that meet the levels defined in NEMA MG-1 (2006) (see Table 12-12). Motors manufactured after December 19, 2010, must comply with the law.

First of Three Parts

This three part primer is a basic introduction to AC power for those in the pump industry who need a place to start. It will also provide several web references to access if you would like to further your understanding of this interesting and essential topic.

Most of us probably never notice the spinning cylinder mounted between the pump and motor, except how easy it is to dis/assemble when a pump or motor is changed out. Otherwise, the disc coupling never factors into our daily routine.

Unanticipated noise and vibration can be problematic for both occupants and processes within structures. Noise and vibration in piping systems can originate at pumps and other mechanical equipment. If the system design does not accommodate vibration, a variety of issues ranging from annoyances to actual business interruptions can occur.