The power at runout required for my pump is 76 hp. Can I use a 75 hp motor and still satisfy the non-overloading (NOL) requirement?
Depending on the wording of the specifications, some or all of the motor service factor may be used to satisfy the non-overloading requirement. Theoretically the end of curve power may be reduced somewhat by polishing the impeller to gain a little efficiency and reduce the power to the required level. Polishing impellers is not as effective as many people think so you will need to inquire about this possibility prior to quoting the unit. Practically however one should be careful about sizing motor power to the Nth degree. If the maximum power is way off to the right then the above scenario will work fine. However if the maximum power is close to the operating point then sizing the motor power too close to the published absorbed power could prove costly. All Armstrong pumps are designed and built to meet Hydraulic Institute (HI) ANSI/HI 1.6 2001 standards. Because of casting variations and necessary machining tolerances seemingly identical pumps may produce different test results. HI te
