A well-maintained pump system can reduce electric costs and extend the life of the pump.
Electric Motor Basics
Factors Affecting Motor Life
The following operation and maintenance tips can increase pump efficiency and extend motor life:
- Surrounding temperature
- Operating voltage
- Service factor
- Type of bearings
- Motor enclosure
- Ambient temperature: the rating for motors at sea level is generally 104° F.
- Sunlight: direct sunlight can increase motor temperature by as much as 20° F.
- Low operating voltage: motors operating at a lower voltage draw more current as they try to reach the rated horsepower, causing them to run hotter (on average, 1.5° F for every percent change in operating voltage).
- Overloading: when horsepower demand is greater than nameplate rating, the motor draws more current and can heat up.
- Altitude: motor temperature increases about 1° F for every 330-foot rise in elevation; most will operate in the rated temperature range to an elevation of 3,300 feet. Motors operating above this elevation may require a service factor of 1.15 because windings can overheat.
- Keep ventilation screens on the motor clean.
- Build a well-ventilated shed or sunshade over the motor.
- Make sure that the motors internal fan is working.
- Perform required maintenance on an ongoing basis.
- Maintain the area around the pump for proper ventilation.
- Protect motor from extreme weather.
Ventilation and Shade Help
Increases in motor temperature can result from several factors. As a motor runs, heat in the windings increases winding resistance, which requires more current to operate at its given output. This generates more heat until optimum operating temperature is reached. Motors with poor ventilation or operating in direct sunlight will generate additional heat, draw more current and increase operating costs. Good ventilation and shading the motor can reduce costs.