Positive Displacement Pumps

Fast Facts

Industry:

Water and Waste Water

Customer Type:

OEM

Degree of Integration:

Simple

Ease of Application:

Easy

Performance Level Required:

Low

Suggested ABB Solutions:

ACS350
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.

Communications

Applications that involve multiple drives or drives controlled by PLC or other supervisory device often require communications via a defined network.
Requires: A drive that has a standard or optional connection to the desired network.

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.

Long Motor Cable Length

Motors are rated by the manufacturer for the voltage resistance of the insulation system. If this insulation system voltage is too low, voltage reflection from the drive could cause motor failure. This is particularly important if the motor is a long distance from the drive and if the motor is an older motor being retained for the application.
Requires: A drive that has the lowest dv/dt or long cable mode of operation.

Overload Torque

Applications may require varying degrees of overload capacity for starting, accelerating, or intermittent duty. This overload capacity must be supplied by the drive as current and by the motor as torque.
Requires: A drive that has sufficient overload capacity.

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.

Power Loss Ride-Through

Applications that control a continuous process cannot afford to stop because of short power outages or dips. The process must continue to run through these outages, typically 2 to 3 cycles long.
Requires: A drive that has sufficient power loss ride-through capability.

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.

Sensorless Vector (SV)

Sensorless Vector is a motor control method that is often used to maximize torque production in the motor for loads that have significant overload requirements. It is NOT a torque control (regulation) method. This algorithm maintains a constant magnetizing (flux) current from zero to base motor speed. The output voltage is increased proportional to load. Automatic or manual tuning identifies key motor parameters including IR drop and nominal flux current, allowing automatic voltage boost at low speeds proper flux current maintenance.
Requires: A drive that offers this motor control method when torque production must be maximized.

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.