Induced Draft Fan

A centrifugal fan that creates suction on the outflow end of the process, drawing air to the inflow.

Fast Facts

Industry:

Customer Type:

User, OEM, Contractor

Degree of Integration:

Simple

Ease of Application:

Easy

Performance Level Required:

Low

Suggested ABB Solutions:

ACS550
ACS800

Required Drive Features

Long Acceleration

The drive can control the rate of acceleration and deceleration of the motor and load. These features control the amount of time the drive takes to increase or decrease the output during speed control.
Requires: A drive with programmable times sufficient for the application.

Analog I/O

Each application has specific requirements for I/O. Analog I/O is generally used to read process signals and output signals proportional to drive status. Analog I/O is generally Voltage (0-10V) or Current (0(4)-20mA). The type and number required by the application must match the drive.
Requires: A drive with sufficient number and type of analog I/O.

Critical Avoidance

Some applications have mechanical resonance points that cause the mechanics (shafts, belts, etc.) to oscillate. These oscillations can rapidly cause mechanical failure.
Requires: A drive that, through programming, can assure that these critical speeds are 'skipped' over and avoided.

Dynamic Brake

Applications that require rapid deceleration or quick stops can regenerate energy back to the drive. A dynamic brake dissipates this energy through a resistor as heat.
Requires: A drive that has an internal DB chopper and connectable resistor or has an external DB kit.

Fan / Pump Control

Many fan or pump installations have a wide spectrum of flow variations. These include water and sewage systems, process, and other industrial applications. Excellent flow control can be achieved by using a variable speed drive on one fan or pump and using the drive to control other units at fixed speed.
Requires: A drive with built-in Fan/Pump Control software.

PID Loop

An internal function provides closed loop process control with proportional, integral and derivative (PID) control. The PID function reads an analog input to the drive and compares it to a desired setpoint. The PID loop adjusts the drive output frequency (and therefore the process) to make the input value equal the setpoint.
Requires: A drive with one or more internal PID loops to eliminate the need for external hardware.

Speed Range (10:1)

All applications operate over a given speed range, defined as the ratio of maximum continuous speed to minimum continuous speed.
Requires: A drive that can produce the needed torque and speed torque regulation (accuracy) over the required speed range.

Motor Control Type

Volts per Hertz (V/Hz)

Applications that do not require significantly more torque than the original motor rating can most often be addressed by a drive using V/Hz algorithms. Loads, such as centrifugal fans and pumps or simple conveyors, are difficult to overload and therefore do not require the performance of other motor control algorithms. Simply maintaining a fixed ratio between drive output voltage and frequency is sufficient.
Requires: A drive that offers this motor control method when simple speed control with rated torque is required.

Regulation Type

Speed

Applications that depend on accurate speed to accomplish the task require a drive that can control or 'regulate' speed.
Requires: A drive that regulates speed to the needed accuracy. Methods include open loop, slip compensation and encoder feedback.