Wiring Diagrams

Where have you looked so far?

let me check my pocket.....

_{<scratch, rattle, thud>}

Nope. Sorry. Fresh out of them. Try Stinky Pete.

Based on your previous question, how do you expect to get a job as an Engineer if you don't know how to

a) Read instructions

b) Perform a simple internet search

Engineering is about more than asking someone else to perform simple (and obvious) tasks you should be capable of after all.

Jack - A real Electrical Engineer slightly insulted you group yourself in with me. I worked as a frickin NASA subcontractor on the Mars mission and you want me to perform an internet search for YOU!

_{<end of rant. Merry Christmas all>}

This drawing may help:

- MS

Could I be wrong in reading the circuit correctly. How does the circuit, prevent accidental reversal of direction, when the motor is running? The operator is not expected to make such stupid mistakes? Any suggestion of some effective interlock please?

If such functionality is needed... an "anti-plugging switch" is required to be inserted in to the control scheme.

• "How does the circuit, prevent accidental reversal of direction, when the motor is running? "

See the NC contacts of the opposing contact in each coil circuit? Figure it out.

I just noticed the poor location of the two N.C. contacts. It would be much better if these contacts were just before the two starter coils. The way it is now... when running forward, if someone presses the reverse button, the starter will kick.

• "I just noticed the poor location of the two N.C. contacts. It would be much better if these contacts were just before the two starter coils. The way it is now... when running forward, if someone presses the reverse button, the starter will kick."

Oh my, you are absolutely right! I failed to catch that. Bad drawing, should be ignored.

That just goes to show you the value of using the internet as a substitute for proper engineering !

The drawing that is provided in comment # 5 is not a bad drawing, rather it is to be considered as a simple drawing for forward / reverse motor control (mentioned within the drawing). It is obviously not a real drawing. If anyone is interested to see the real drawing for the reversible motor starter, here is one. Due to the size, it may not be readable - I am sorry for this.

This is a drawing for FVR (Full Voltage Reversible) starter for local manual control of Motor Control Valve (MOV) which operates in both directions. The overload relay shown in the drawing is the E3 Plus (Rockwell Automation). Again keep in mind, the protection and control of such starter fully depends on the specific case and condition of the use of the motor.

- MS

Unless the starter contactors are linked with a mechanical interlock (which is missed off the drawing).

It's not just a <...wiring diagram...>, though.

There needs to be a mechanical NAND gate between the two contactors.

Otherwise the circuit protection devices may operate.