What kind of torque does an asynchronous induction motor have?
The torque developed by an asynchronous induction motor varies when the motor accelerates from zero to maximum operating speed. The Locked Rotor Torque or Starting Torque is the torque an electrical motor develops when starting at zero speed.
How to calculate the torque of a motor?
In metric units the rated torque can be expressed as. T = 9550 P kW / n r (2) where . T = rated torque (Nm) P kW = rated power (kW) n r = rated rotational speed (rpm) Example – Electrical Motor and Braking Torque. The torque of a 60 hp motor rotating at 1725 rpm can be calculated as: T fl = 5252 (60 hp) / (1725 rpm) = 182.7 lb ft
Which is the torque in synchronous Watts?
The air gap power P g is also called as the Torque in Synchronous Watts. Synchronous Watt is the torque that develops the power of 1 Watt when the machine is running at synchronous speed. Now, the electrical power generated in the rotor is given by the equation shown below:
What do you mean by full load torque?
Full-load (Rated) Torque or Braking Torque. The Full-load Torque is the torque required to produce the rated power of an electrical motor at full-load speed. In imperial units the Full-load Torque can be expressed as. T = 5252 P hp / n r (1) where. T = full-load torque (lb ft) P hp = rated horsepower.
When to use high or low starting torque?
A high Starting Torque is more important for application or machines hard to start – like positive displacement pumps, cranes etc. A lower Starting Torque can be accepted for centrifugal fans or pumps where the start load is low or close to zero.
When does the torque of a motor decrease?
When a motor starts and begins to accelerate the torque in general will decrease until it reach a low point at a certain speed – the pull-up torque – before the torque increases until it reach the highest torque at a higher speed – the break-down torque – point.
What kind of motor can I use for more torque?
If a load requires more power or more torque than a single-phase AC motor can provide, then an AC three-phase squirrel cage-type induction motor (SCIM) can be utilized. When paired with variable frequency drives, these motors are adjustable in speed and have very high efficiency.