Universal T milling machine from Chester : Issue with Starting

[MOHAMMED MECHERIParticipant @mohammedmecheri39791]

I am using a T mill universal milling When the emergency knob is disengaged its not able to hear the knocking sound, no green light on the start button, Machine is unable to start.

But the light, DRO MEter is working.

I am attaching pictures. Please help

[MOHAMMED MECHERIParticipant @mohammedmecheri39791]

[JasonBModerator @jasonb]

Is it one of the red emergency buttons that you have to turn and pull out to activate it.

Also make sure chuck guard is closed.

[BazyleParticipant @bazyle]

Is it both the vertical and horizontal motors that both don't work? Do either work in reverse?

Do you have a circuit diagram? there will be safety interlocks on some of the doors and guards and it is common for the switches to not close properly if the door is not fully closed. You should identify the wiring for these switches which will be wired in series so that any one can break the circuit. You will need a voltmeter to follow the circuit and check if each switch is closed.

[Ian ParkinParticipant @ianparkin39383]

Turn off all the QF switches 1-6 and turn them back on

sometimes these trip without showing

after then we need a diagram

[Howard LewisParticipant @howardlewis46836]

Obviously, there is power to the machine for the light and the DRO.

Checking through against the circuit diagram, in a similar fashion to your lathe should lead you to the fault. Again, it sounds as if there is a relay that is not receiving current, or that it has failed..

Suggestion: start checking the wiring back from the relay until you find, hopefully just a loose connection.

HTH

Howard

[MOHAMMED MECHERIParticipant @mohammedmecheri39791]

[MOHAMMED MECHERIParticipant @mohammedmecheri39791]

[MOHAMMED MECHERIParticipant @mohammedmecheri39791]

[JasonBModerator @jasonb]

Just looked at the e-stop button again and it is one that you need to turn and pull to set, if you are just pushing it then the circuit will remain open.

[MOHAMMED MECHERIParticipant @mohammedmecheri39791]

I checked the safeguard, emergency switch .its not the issue. I opened the box and checked the QF switches, opened the panel in front( consists start button, spindle speed knob, emergency switch) to check for loose connections). Got almost 20 drawings from the manual. My electrical knowledge is weak. How I can check the connections with a multimeter to reach a conclusion where is the problem occurring?

[MOHAMMED MECHERIParticipant @mohammedmecheri39791]

@Jasn B : I tried it. I pulled the emergency stop. but it still the same

[Ian ParkinParticipant @ianparkin39383]

Those diagrams dont seem to be of your machine

theres no VFD for a start

Is yours single phase or 3 phase?

[David JuppParticipant @davidjupp51506]

If your electrical knowledge is weak – I suggest you stop and get help from somebody that knows what they are doing.

[Les Jones 1Participant @lesjones1]

First check that you have 24 volts AC on the secondary of of the 24 volt control transformer. I think it is the one at the top right of the control box. I can't see the labels clearly so can you take a properly focused picture (Or pictures.) of the control box with your camera pointing straight at it. (Not looking down at an angle as in your picture in your first post.) If you have 24 volts on the output of the transformer then check if you have 24 volts AC across the coil of KM1. (This contactor should be closed except when the emergency stop button is pressed.)

Les.

[shaun hillParticipant @shaunhill88399]

Hi , i have a T mill and the same thing happened to me, try resetting the Rcd the left hand one, middle row as shown on you picture, pressed them in and out a couple of times and hey presto it sprang back into life, even though they appeared ok to begin with

[ZanParticipant @zan]

If the circuit diagram is for your machine you have a problem as there should not be any switches between the vdf and the motor. The diagram indicated the vdf could be on the far left off the diagram.

i see two transformers in your photos what voltage are they, and what do they power? Trace the wires.

I suspect the vvdf is blown at its output. When converting my Bridgeport to vdf and 240 v a significant amount of fuses and other 3 phase junk had to be deleted. The vdf has adequate overload protection built in..

the main motor is now worked by a contractor which now sends the digital run signal to the vdf inputs and thus running the motor triggered by the normal push button latched with the same contractor

perhaps a separate mans lead direct to the vdf will test it, it should light up If it dies Its then up to you about risking starting the main motor .. do take care with this! It won’t start direct from the vdf itself as the parameters on it wil be set or remote operations

good luck

You will have to trace back the connections from the DRO and lamp I’m not sure on this, but they probably conn coed directly to the mains input. In the diagram they are driven from a transformer. What voltage is the lamp? Looks like 24 v

[MOHAMMED MECHERIParticipant @mohammedmecheri39791]

@ Les Jones 1

[Les Jones 1Participant @lesjones1]

Did you get 24 volts AC on the secondary of the 24 volt control transformer and the coil of KM1 ?
I still cannot read the terminal labels on the contactors and circuit breakers or the markers on the ends of the cables.
If your camera has a macro mode you could photograph the individual contactors and circuit breakers. You could also use manual focus instead of auto focus.

Les.

[martin perman 1Participant @martinperman1]

Posted by MOHAMMED MECHERI on 10/07/2019 08:36:27:

@Jasn B : I tried it. I pulled the emergency stop. but it still the same

Mohammed, you say you pulled the EM stop but did you turn it clockwise as the arrows moulded on the button indicate, you need to twist clockwise and pull.

Martin P

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