When choosing a motor for an application, a primary consideration may be the speed range it’ll be operated in. Whenever a motor is run substantially slower than its rated base speed, a number of potential adverse effects may come into enjoy, including reduced cooling performance, reduced power efficiency and a alter in the motor’s quickness and torque features. To mitigate this problem, some motors and velocity controllers have been designed especially to drive lots at low speeds with specific control.

Most domestic and commercial motor applications use 3-phase asynchronous induction motors, which speed reducer gearbox operate at a speed that’s determined by the frequency of the supply power. When an application operates at a continuous speed, the only thing that is required could be a gearbox or rate reducer that brings the motor speed down to the required level. Nevertheless, many applications need the rate of the engine to be various during operation.

This is usually achieved utilizing a VFD or Variable Frequency Drive, which controls the speed by modifying the frequency fed to the motor. Selecting the most appropriate motor and VFD type depends upon a variety of factors, however, it is necessary to first look at the way the characteristics of a motor change when the swiftness is reduced.

A motor usually has a base speed, specific by the product manufacturer, that it can be made to operate at. However, if a engine is managed below the bottom speed, it could experience reduced efficiency of the cooling system. Especially with frequently used Totally Enclosed Enthusiast Cooled (TEFC) and ODP (Open Drip Proof) motors, where in fact the cooling program consists primarily of a shaft-mounted enthusiast, a reduction in speed results in reduced airflow over the motor and loss of cooling, and heat buildup occurs. Especially when the engine is operated with complete torque at low speeds, heat can quickly build up inside the motor to harmful levels.