Is high starting torque good?

Locked Rotor or 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.

Should torque be high or low?

Because there is generally a limit on how fast you can spin an engine, having higher torque allows for greater horsepower at lower rpms. This is also why people talk about “low-end torque” being important for better power at slower speeds.

Does more current mean more torque?

Torque is directly proportional to the current. Torque is inversely proportional to the speed. Load plays a very important role.

What is the meaning of high starting torque?

It means your motor / rotational machine has high moment of inertia. Larger moments requiring more torque to rotate. For rotating machines (like electric motors, ic engines) if the moment of inertia is high, since the torque is rotational moment, starting torque will be higher.

What is a starting torque?

Starting torque is the torque transferred by the shaft coupling during run-up (see Start-up process). It is calculated based on the ratio of power (P) to angular velocity (ω) and is represented as a rotational speed function.

Which has high starting torque?

The capacitor start motor develops a much higher starting torque of about 3 to 4.5 times of the full load torque.

Is torque better at lower or higher rpm?

“Higher torque at lower r.p.m. means you have a lot more horsepower at lower r.p.m., which makes it easier to tow things from a standstill. “High torque at higher r.p.m. means more power while you’re already underway, which usually results in higher top speed.

What is relation between torque and current?

Mechanical or load torque is proportional to the product of force and distance. Motor current varies in relation to the amount of load torque applied. When a motor is running in steady state, the armature current is constant, and the electrical torque is equal and opposite of the mechanical torque.

What is low starting torque?

As R2 is neglected, starting torque now depends upon X20 which is maximum at starting as slip is 1. So starting torque is low in induction motors. To get maximum starting torque, resistance is added to the rotor while starting slip ring motors, which is reduced gradually as motor picks up the speed.

What does low starting torque mean?

the start-up torque of a motor is the maximum torque which it is capable of producing from a standstill. If the start-up torque of your motor is not greater than the start-up torque of your mechanical system, then the motor will not be able to get the system moving.

How does the starting current affect the starting torque of motor?

The starting current may be lower or higher for producing higher starting torque. The starting torque of the motor is proprtional to the product of main flux, rotor current and rotor power factor. The flux in the motor is more or less constant, and the starting torque depends on the rotor current and rotor power factor.

How to reduce the high starting current of induction motor?

Therefore different starting of induction motor, methods such as (star delta starter, auto transformer starter and other starting methods) are employed in order to reduce the high starting currents of induction motor. Induction motor can be compared to an electrical transformer with the secondary short circuited.

What happens if the starting current of a DC motor is high?

Such high starting current of DC motor creates two major problems. Firstly, current of the order of 400 A has the potential of damaging the internal circuit of the armature winding of DC motor at the very onset.

How to choose the right motor for your load?

The more quickly a load must accelerate from rest to normal rotational speed, the greater must be the torque capability of the motor driver. For very large inertia loads or loads that must be accelerated quickly, a motor having a high starting torque should be applied.