Pid - Toshiba G3 Workbook

The built-in PID of the G3 can be used to maintain a constant process variable such as flow, pressure,
temperature, and level. In the example below, the drive is used to vary the speed of the motor/pump to
maintain a constant pressure at the output of the pump. As the valves on the output of the pump are
opened, the pressure goes low. The drive senses this via a 4-20 mA feedback signal and speeds up to
increase pressure up to the desired level. The drive will slow the motor/pump down as the valves close.
The rate at which the drive responds to changes is adjustable via three parameters (Proportional Gain,
Integral Time, and Differential Time) and will have to be field-tuned. Later in this guideline, PID
D/A
500
Check your transducer's schematic for connection information. The above diagram is typical for a loop-
Separately powered isolated transducers feed into the 'IV' and "CC" terminals. If your transducer is not
isolated, order an isolated input board. The inputs to the standard G3 are not isolated; do not connect the 'CC'
Set SW1 (to the right of the phone jack on the control board) in the 'I' position.
For additional assistance, please contact Toshiba Adjustable Speed Drive Marketing Dept. at (800) 872-
applications will be discussed in general.
MOTOR
G3
P24
IV
CC
powered transducer.
terminal to ground.

PID

Introduction
Connections
PUMP
4-20 mA feedback
2192
Output Flow
VALVES
//
//
Transduce
Area in which constant
pressure is desired
22
48