Milling macine problem

[mrmatt]

Ok. Looking at your third photo I'm willing to hazard a guess that 0 and 2 on that terminal rail is your 24 v control. If so there's a good chance that you will have either 0 or 2 wires at the A1 terminals on the contactors behind the L 1 terminals. If there are wires numbered 0 at these A1 terminals then check for continuity between there and the 0 terminal at the terminal rail. If the wires are numbered 1 then check for continuity to the 1 terminal on the rail. This should more or less confirm that you have a common to the contactors and suggest that there is a break in the stop circuit.

From memory they are labled 0. I will check for continiuity tomorrow. If no continuity is shown does this indicate a stop issue? I took one contactor out and didnt see A1 or A2 labled but i am guessing the ones behind the 3 pases are these connections to the coil as there is nothing else in the contactor and if i remember right the ones labled 0 are looped into the other contactors also

 

[johnstantine]

Also, I know you said you checked the stop buttons but, you could completely eliminate them by shorting out the two wires on the buttons then trying to run the machine. Just be ready to hit the isolator if it all goes wrong.

 

[Hawk81]

have you tried the reset button on the overload

 

[johnstantine]

From memory they are labled 0. I will check for continiuity tomorrow. If no continuity is shown does this indicate a stop issue? I took one contactor out and didnt see A1 or A2 labled but i am guessing the ones behind the 3 pases are these connections to the coil as there is nothing else in the contactor and if i remember right the ones labled 0 are looped into the other contactors also

You should (in theory!) have continuity from terminal behind L1, all the way to the same numbered terminal on the rail and also right through to one leg of the secondary on the control transformer. If you DO have good continuity from transformer right through to contactor then it suggests problems is on stop circuit.
Think of the terminal behind L1 as being a bit like a neutral, in that you wouldn't expect that leg to be switched.

 

[johnstantine]

If the wires going to the terminals behind L1 are numbered 0 then you should have 24v between them and the terminal 2 on the rail. If this checks out then you need to trace from terminal 2 right through to start buttons and stop buttons. There should be 24v between terminal 0 and one side of start buttons, if so there should be voltage between terminal 0 and each side of stop buttons.
Do the pump, traverse, and motor each have their own start and stop buttons? or is there one stop button that stops everything?

 

[silva.foxx]

So... by now, mrmatt, you would have drawn up a schematic of what you have. You are the best man for that job. 3 DOL starters and stop/start circuits. You should then be able to trace the circuit for continuity from +24v through components through to coils. Put temporary shorting links in to test (hence the importance of drawing up the schematic).

You will get there. You will do it. You'll find the fault and think "Is that all it was?" and may feel a little embarrassed that it was something so simple or so obvious. I've had plenty of them and certainly not alone! Good luck.

 

[silva.foxx]

What details have you got on the milling machine?

Make

Model

Perhaps a schematic can be sourced on t'interweb.

 

[caddy]

There is 24v out of the transformer for the control gear traced this to the start buttons. There are 3 start buttons, one for each contactor, and 4 stop buttons one for each contactor and and Emg stop. The emg stop functions correctly I have double checked this.

Do you get 24v back to tha panel connections when you press the start button ? if so then where does the cable go from there.

 

[ACDC]

Out of curiosity, have you checked the resistance of the contactor coils? if they have gone t**s up, you will lose your retaining circuit if it goes through a N/O contact on the contactor.. Just a thought before you start ripping out cabling.

 

[silva.foxx]

Is our miller running yet?

I'd have sacked you by now!

 

[Guest123]

I'm intruged to know the outcome too.

 

[mrmatt]

No its not running yet but I have not had chance to look at it since my last post as I have had a lot of work on.

I am planning on looking at it tomorrow afternoon, good job they havnt needed to use it

 

[silva.foxx]

Is this miller on ebay's "for spares or repair" section yet?



.

 

[Darkwood]

It smells alot like as mentioned before the stop circuit is open, this can be due to limit switches on door panels etc as well as the stop buttons, ask and find out if any panels have been taken off like the access panel to the belts or motor, if you trace your stop circuit you could short it out and see if the problem lies within it, but if you can find a diagram just see what is in the stop circuit, also as mentioned before check voltage at contactor coil when your pressing the start button if its there then the coil on the contactor has failed and needs replacing.

 

[mrmatt]

Thanks for the replies guys. The machine is still not running (as i have not been back to look at it) they have another machine different but does same job so there is no rush. Ive got too much happening at the moment and havnt had the time to go back and do a freebie,
Hopefully once the rewire I am on is done ill go and take another look

 

[mrmatt]

Drum roll please..... Finally Fixed

Indeed it was in the stop circuit.. Faulty Emg stop button

Thanks all for your help

 

[silva.foxx]

Thanks mrmatt for feeding back the result. Nice one. Finally put to bed, eh?
Said it would be something simple. These faults just like to play hide and seek. All the fun of the fair...and more!

Cheers

 

[jpmiff]

good experience, if this type of fault reared up again would be the first thing to check out.great.