How does starting torque compare to running torque?

Starting torque is the amount of torque that is required to get an object, such as a motor or pump, moving from a standstill. This value is often significantly higher than the running torque, which is the torque needed to keep the object moving once it has started. The reason for this difference is primarily due to inertia – starting from a complete stop requires additional effort to overcome initial resistance and any static friction present in the system.

In most applications, especially in hydraulic systems, it is crucial to have adequate starting torque to ensure that components can begin their operation. If the starting torque is not sufficiently high, the system may fail to initiate movement, which can lead to operational failures or even damage to the equipment.

The distinction between starting and running torque is essential for sizing motors and pumps correctly. It ensures that the selected components can handle the initial load they will face when starting. Understanding this relationship is fundamental in hydraulic system design and operation, which is a key aspect of the IFPS Hydraulic Specialist Certification.