motor control

wgreen · Nov 10, 2002

I am in a basic PLC class, just learning, can anyone give me a ladder diagram for a three phase motor, running forward, (non-reversing), that can also be jogged. One stop, one start, one motor. Thanks

olias · Nov 10, 2002

This is an excellent way to learn to program. This is as simple as you get. Good luck and stop asking others to think for you.

mark sutherland · Nov 11, 2002

come on you just want your course work done for you ill give you a clue you need 3 inputs 1 output and 2 retaining coils now use your brain and try

olias · Nov 11, 2002

Actually, He only has two inputs, start and stop, so he'll have to hold the stop button and jog with the start. Now, he only needs one output.

JDW · Nov 11, 2002

start Phase
A
---| |--------------------------()-
Start phase
B
---| |--------------------------()-

start phase
C
---| |--------------------------()-

mark sutherland · Nov 11, 2002

Ok though you had a jog switch as well.are you running the 3 phase motor from the PLC or through a contactor.

Tom Jenkins · Nov 11, 2002

This is a standard motor control ciruit. If this is an industrial application you should have some manufacturer's catalogs laying around that you can look at for hints. If this is a student exercise, yopu should make an attempt, however feeble, and post it here. We will then give more hints and critique the logic.

rsdoran · Nov 11, 2002

I can offer 2 sites that may help you in this endeavor

http://claymore.engineer.gvsu.edu/~jackh/books/plcs/
download the PLC harware PDF

http://www.reliance.com
Has abundance of info pertaining to motors and controls

As stated your request is for a simple circuit that is easily found if you take the time to look and read. If we misunderstood your question then rephrase and ask again please.

DickDV · Nov 11, 2002

In my experience, jog can mean at least two different things.

First, it can mean that there is a separate jog button that, when pushed causes the motor to run, and when released, causes the motor to stop. Operation is completely independent of the start and stop buttons.

Second, it can mean that there is a two position selector switch which, in run position, causes the start button to latch up leaving the motor running until the stop button is pushed. In jog position on the switch, the start button causes the motor to run when pushed and does not latch up, allowing the motor to stop when released.

The control scheme for these is significantly different.

wgreen · Nov 11, 2002

Sorry if I didn't ask my question correctly, I diagramed a logic ladder with a stop, start, overload, memory, and ote, when I added the jog button the program would not run, after working on it for three days I ask for help because I thought there was something I was doing wrong. Tonite in class I discovered that it was a trick question and I have not been given all of the necessary info. I have since figured it out. Sorry if I was confusing.

Mr. Allen Bradley · Nov 13, 2002

ladder diagram

start stop overload contactor coil (C1)
-----||-------------------|/|---------|/|----------()----
|
C1 JOG |
-----||--------|/|---|
|
|
JOG |
-----||--------------|

try it!

Mr. Allen Bradley · Nov 13, 2002

ladder diagram

excuse, they have some problem with my last reply

Mike Williams · Nov 13, 2002

Mr. Allen Bradley, Please lower your prices!

Steve Bailey · Nov 13, 2002

Mike, I expect that your solution is for a separate 'Jog' pushbutton wired as a normally open device, and the intent is to have the motor run while the Jog pushbutton is pressed and stop when the Jog pushbutton is released.

Unfortunately, The logic that you presented will not work that way. The starter will seal itself in with the Jog pushbutton just as it will when the 'Start' pushbutton is pressed.

Mike Williams · Nov 13, 2002

I put up what MR. AB attempted to show just that. YOU CAUGHT IT TO QUICK! You guys are awsome.

motor control

wgreen

Member

olias

Member

mark sutherland

Member

olias

Member

JDW

Member

mark sutherland

Member

Tom Jenkins

Lifetime Supporting Member

rsdoran

Lifetime Supporting Member

DickDV

Member

wgreen

Member

Mr. Allen Bradley

Member

Mr. Allen Bradley

Member

Mike Williams

Member

Steve Bailey

Lifetime Supporting Member + Moderator

Mike Williams

Member

Similar Topics