insalespart-ga:
Typically electric control panels for industrial application are used
for Process Control - for example in a plywood mill where logs are
mechanically reduced to wafer thin sheets or in a chemical plant where
batches of liquid and solid chemicals are heated, cooled, mixed, etc.
The Process Control may be as simple as an on/off control or a complex
an automated assembly line.
The majority of process applications employ motors that through a
variety of mechanisms feed, mix, cut or in some way interact with the
material in the process. Other equipment utilizes electricity directly
for heating or welding or indirectly, such as Lasers, plasma
generators, UV light, etc.
Obviously this is a very broad topic spanning simple motor control
applications to highly sophisticated interfaces for automated
equipment. In their simplest form simplest Electric Control Panels use
pushbuttons, switches, or speed controls to start, stop or control a
motor and indicator lights to monitor the state of the motor (i.e. on
or off). At their most complex processes they are interfaced with
Programmable Logic Controllers (PLC) or computers running complex
programs that utilize feedback sensors to monitor the process.
However, even the most sophisticated control panels are based on
simple blocks.
For example a motor control panel maybe used to start, stop, change
direction or varying the speed of a motor. There may be a feedback
device such as a limit switch that stops the motor when the material
reaches a certain point in the process (for example I installed a
limit switch this weekend on a winch motor that lifts a scoop attached
to a barge used for skimming algae off of a lake. The limit switch
prevents the winch from binding.) A more complex application may use a
machine vision system to detect defects as the material passes by it
and in turn switches on a program in a PLC that slows, stops or
redirects the material in the process (an example of this is the
equipment used in plywood mills to cut out and patch defects in
plywood sheets). The more sophisticated application is built on the
simple one.
The following web site offers a self-paced study course that will
introduce you to the basics -
http://www.enm.com/training/siemensstepcourses.asp#Basics%20of%20Control%20Components
I would also recommend that you investigate manufactures websites -
here is a short list:
Allen-Bradley (Rockwell Automation)- http://www.ab.com/
Siemans - http://www.sea.siemens.com
ABB - http://www.abb.com/
Cutler Hammer/Eaton - http://www.eatonelectrical.com
GE Fanuc - http://www.geindustrial.com/cwc/gefanuc/index.jsp
Manufacuters reference:
http://www.processregister.com/home.asp
http://www.electric-find.com/controls.htm
Following are a some reference sites that I find handy:
http://www.eng-tips.com/supportus.cfm
http://cipco.apogee.net/mnd/home.asp
http://www.controlmag.com
http://ics.pennwellnet.com/home.cfm
http://www.automationtechies.com/sitepages/pid0.php
Here is a handy glossary for industrial process control:
http://www.processindex.com/glossary.htm
Please let me know if I can elaborate on a particular aspect of
Electrical Control Panels.
Waldo |
