How to Choose the Right Motor Torque for Your Equipment

Torque is one of the most important factors when selecting an electric motor. Many equipment failures happen simply because buyers pick a motor with insufficient torque. If torque is too low, the machine cannot start or will shut down under load. Too much torque wastes energy and increases costs. Here is a simple guide to help you choose the right motor torque.

1. Understand two key torque values

Running torque: The constant torque needed when your equipment works at normal operating speed.
Starting torque: The torque required to start up the machine from rest. For heavy-load machinery, starting torque is usually higher than running torque. You must make sure the motor can handle the startup load.

2. Calculate your actual load requirement

Confirm these details before selecting:

Weight or resistance of the driven equipment
Operating speed and working cycle (continuous or intermittent)
Extra friction from gears, belts, reducers and bearings

For pumps, agricultural machines and lifting equipment, friction and inertia will greatly increase torque demand. Remember to leave a safety margin, usually 1.2 ~ 1.5 times your calculated load torque.

3. Match torque with motor speed & reducer

Motor torque relates directly to speed. At the same power, lower speed brings higher torque. If your high-speed motor cannot supply enough torque, you can use a gear reducer to increase output torque. Do not only look at motor power (kW). Two motors with the same power rating may have very different torque at different speeds.

4. Consider working environment

Check your working conditions:

Continuous heavy duty or frequent start-stop cycles
High temperature, dust or outdoor installation Frequent startup will require higher starting torque and stronger motor structure.

5. Get professional support

If you are unsure about torque calculation, share your equipment parameters with our team. Tell us your machine type, load, speed and usage cycle. LISU MOTOR engineers can recommend the correct motor and reducer combination for your application.