What are the Benefits of using a Frequency Converter With an Electric Motor?
Wednesday - 06/11/2019 14:41
Variable speed electric motors play a crucial role in supporting building systems, including HVAC, exhaust, and manufacturing lines.
Industrial motors that are built power to these systems, and are not kept running at all times, can benefit from being connected to a frequency converter — a device that converts one frequency of alternating current (AC) to another frequency of AC.
As their name implies, variable speed motors can operate at variable speeds, switching from one speed to another based on the wattage they must deliver to the equipment for which they provide power. When the operation of the motors is governed by a frequency converter, it offers the following benefits that would not be possible without the use of the converter.
1. Controlled Starting
When motor startup is engaged using the “across the line” model, it can take up to eight times the motor’s full operating current to achieve ignition and support the load. This causes the motor to work harder and create more heat than it would if a converter were used to control the motor’s startup speed. Here, the benefits of using a converter are less energy consumption and less wear on the motor.
2. Acceleration Control
Controlled starting leads to controlled acceleration. When an motor accelerates using the “across the line” model, it creates a mechanical shock to the equipment and the load it supports. This shock can cause the motor to wear prematurely and fail during service. Here, the benefit of using a frequency converter with an electric motor is that the motor experiences less wear.
3. Variable Operating Speed
In addition to controlling motor startup and acceleration, frequency converters can also control the operating speed of a motor. The goal is to supply the motor with only as much electricity as it needs to support the specific operation. Here, the primary benefit is that the motor consumes less energy than it would if it were operated using the “across the line” model.
4. Controlled Stopping
As with controlled starting, controlled stopping helps reduce wear and tear on the motor. Instead of gradually increasing the motor’s acceleration, the converter gradually decreases acceleration until the motor comes to a soft stop. Here, the benefit is that the motor’s acceleration decreases smoothly, preventing its moving parts from experiencing a mechanical shock due to power suddenly being cut.