When choosing a electric motor for an application, a primary consideration may be the speed range it’ll be operated in. When a motor is run considerably slower than its ranked base speed, several potential adverse effects may come into enjoy, including reduced cooling effectiveness, reduced power effectiveness and a alter in the motor’s acceleration and torque features. To mitigate this issue, some motors and swiftness speed reducer gearbox controllers have been designed especially to operate a vehicle lots at low speeds with specific control.
Most domestic and industrial motor applications use 3-phase asynchronous induction motors, which operate at a speed that is dependant on the frequency of the supply power. When a credit card applicatoin operates at a constant speed, the only thing that is required may be a gearbox or swiftness reducer that brings the motor speed down to the required level. However, many applications require the quickness of the electric motor to be diverse during operation.
This is generally achieved using a VFD or Variable Frequency Drive, which controls the speed by modifying the frequency fed to the motor. Deciding on the best engine and VFD type depends on a variety of factors, however, it is necessary to first look at how the characteristics of a motor change when the swiftness is reduced.
A motor usually includes a base speed, specified by the product manufacturer, that it is certainly made to operate at. However, if a motor is operated below the base speed, it could experience reduced performance of the coolant system. Especially with generally used Totally Enclosed Fan Cooled (TEFC) and ODP (Open Drip Proof) motors, where in fact the cooling system consists primarily of a shaft-mounted lover, a reduction in speed results in reduced airflow over the electric motor and lack of cooling, and warmth buildup occurs. Especially when the electric motor is operated with full torque at low speeds, heat can easily build up inside the motor to harming levels.