A variable-frequency drive (VFD, or adjustable-frequency drive, adjustable-speed drive, variable-speed drive, AC drive, micro drive, inverter drive, variable voltage variable frequency drive, or drive) is a type of AC motor drive (system incorporating a motor) that controls speed and torque by varying the frequency of the input electricity.

The basic function of a variable speed drive (VSD) is to control the flow of energy from the mains to the process. Variable speed drives sit between the electrical supply and the motor. Power from the electrical supply goes into a drive and the drive then regulates the power that is …

2004年7月28日 · I've seen two methods for showing a variable speed drive for motors on P&IDs. One is a standard instrument bubble with SIC inside, with a doted line going to the motor/pump. The other is a positioner, commonly used for control valves, which 'indicates' an actuator, attached to the motor/pump.

2016年6月10日 · This article offers a comprehensive assortment of widely utilized P&ID symbols for pipes, fittings, valves, strainers, and various process equipment like pumps, compressors, motors, heat exchangers, and towers, ready for immediate download.

2024年1月2日 · This document contains a diagram summarizing symbols and components related to a variable speed drive system. It includes symbols for a variable speed drive, soft starter, motor rotor starter, power factor compensation, circuit breaker and motor. It also shows an existing transformer, feeders, cable connections and references other drawings.

2023年8月29日 · Usually a VFD is shown as just a rectangle with the term VFD inside, often with the size rating and added boxes above or below for Line Reactors or Load Reactors (abbreviated LR). If the VFD is 18 pulse, some people often show …

In processing systems, VSDs are used to control the mechanical power of the different machines involved in the process. Material treatment can also be controlled by VSDs. A good ex-ample is a drying kiln, in which the hot air temperature must be constant. The process is controlled by controlling the speed of the hot air fans using VSDs.

2008年7月30日 · Anyone out there knows what symbols to use for a VFD and for a magnetic starter in a P&ID? For a DOL motor you don't need to show the starter just a circle with the motor number or drive Number e.g. P-101 for pump 101. For a VFD a box beside the motor with the tag No inside e.g. VSD-101.

The VFD schematic symbol is a visual representation that helps electricians and engineers easily identify and understand the presence and function of a VFD in a circuit. It typically consists of various lines, shapes, and labels that indicate the various …

A variable speed drive (VSD), also known as a variable frequency drive (VFD) or an adjustable speed drive (ASD), is an electrical device used to control the speed and torque of an electrical motor. By adjusting the frequency and voltage provided to the motor, a VSD can vary the motor’s speed to match the desired application requirements ...