So electric motor torque is not constant. There is a region of operation in conjunction with the controller and for certain load conditions which will give the appearance of constant torque.
What is constant torque motor?
Constant torque motors are high-efficiency, brushless DC motors that are based on the same ECM technology described in ECM 2.3 variable-speed motors. … In other words, if the ESP changes, then the motor program will maintain the amount of torque for which it was programmed (this is not the same as constant airflow).
Do electric motors lose torque over time?
The wound field motors generally don’t lose power over time, but the ones using permanent magnets can lose power permanently if they are severely overheated or are loaded too heavily. Those actions can cause the magnets to become weaker.
How do you maintain constant torque?
In order to keep a constant torque, which is directly related to current, the voltage going from the VFD to the motor is increased as the speed increases. On a 460 Volt motor, 460 Volts is only applied to the motor when the speed reaches 60 Hz.
How long do electric motors last?
Some manufacturers estimate 30,000 hours, while others state 40,000 hours. Some will say “it depends.” One thing is clear—a motor should last much longer with a conscientious motor systems maintenance plan than without one. Motor life can range from less than two years to several decades under particular circumstances.
What makes an electric motor go bad?
Stressful mechanical, environmental, and electrical operating conditions can all cause electric motor failure. Electrical failures are winding failures caused by an open contactor, bad connection, blown fuse, excessive heat, electrical overload, or broken power lines.
What does a constant torque mean?
Constant torque loads require the same amount of torque at low speeds as at high speeds. Torque remains constant throughout the speed range, and the horsepower increases and decreases in direct proportion to the speed. … With constant torque loads, the torque is not a function of speed.
Is a pump constant torque?
Pumping applications can be categorized as constant torque (CT) or variable torque (VT). This refers to the relationship of the torque required by the pump to a reduction in speed. … Conversely, when you slow down a centrifugal pump, the performance (pressure and flow) capability is reduced.
What is constant torque speed range?
For example, a constant-torque speed range (CTSR) is expressed as 10:1, or the motor can operate from base speed to 1/10 of base speed (180–1,800 RPM). Generally lower-horsepower general-purpose motors can operate over a wider speed range (20:1) because of their lower temperature rise.