Fractional HP Motors

More Information about Fractional HP Motors

A fractional horsepower motor comes in different types, including induction motors, brushed DC motors, brushless motors, stepper and servo motors. Each type has its own advantages and is suitable for specific applications.

The construction of fractional HP motors typically includes a rotating shaft and stationary magnets or rotating magnetic fields, depending on the motor type. AC fractional HP motors often use a rotating magnetic field generated by the stator windings, while DC fractional HP motors use permanent magnets or a combination of magnets and electrical currents.

Depending on the specific application, fractional HP motors may have features such as totally enclosed fan cooling for better heat dissipation, ball bearings for smooth operation, and open drip-proof construction for protection against moisture and dust.

The performance of fractional HP motors is influenced by several factors, including the frame size, starting torque, efficiency, and speed. These motors are typically rated for continuous operation at their specified power rating.

FAQs

Does a fractional HP motor have the same mechanical energy as a blower motor?

Yes, both fractional HP motors and blower motors have mechanical energy as their output. However, it's important to note that "fractional HP motor" and "blower motor" are not mutually exclusive categories. A blower motor can be a type of fractional HP motor, but not all fractional HP motors are specifically designed for blower applications.

What kind of power supply is required for a fractional hp electric motor?

Fractional HP electric motors typically require a power supply that matches their voltage and frequency specifications. Some larger electric motors may be designed for 240 volts AC single-phase power. Three-phase motors require three-phase power consisting of three alternating currents, typically at voltages such as 208 volts, 230 volts, or 460 volts AC.

Motor Starters, Soft Starters and VFDs

Motor Starters

Motor starters safely start and stop a motor in industrial applications. They are designed with a contactor, overload and circuit protection. They are used when basic motor control is required, where torque on the motor is not a concern and speed control is not needed. The advantages of motor starters include: lower cost, allows for remote operation, allows for monitoring of motor state (with the use of auxiliary contacts) and they are safe and efficient. The disadvantages include: high inrush current that can cause fuses to blow and breakers to trip if the inrush is too high, and the starter will allow a full torque to start the motor which can cause the motor to ramp up to full speed very quickly potentially causing the motor to wear and degrade prematurely.

Soft Starters

Soft starters protect motors from inrush current by gently ramping up the motor to full speed. They provide all of the same functions as a traditional motor starter. The advantages of soft starters include: they are less expensive than a VFD when only startup control is needed, they are a smaller system than a VFD where space is a concern and they prevent unwanted torque upon startup, prolonging the life of the motor. The disadvantages include: they are more expensive than a traditional motor starter and they do not allow for full speed control. 

VFDs

A Variable Frequency Drive (VFD) allows for the slow ramp up of a motor during startup and the slowing down of the motor during shutdown. It also allows for full speed control during the entire run cycle of the motor. VFDs provide the same functions as both the traditional motor starters and soft starters. The advantages of VFDs include: full speed control (start, stop and in-between), more custom control and monitoring, energy savings due to efficient motor usage and less wear and tear on the motors. The disadvantages include: they are more expensive and larger than other motor control options and they generate heat that may require fans or AC units.