View Full Version : Problem OKUMA LT25-M

03-14-2009, 08:57 AM
Hello Folks!
i are new with the Okuma Machines, and justi come in a USED lathe to our Shop
the machine a twin turret LT25M with a OSD5020 control.

We have 2 problems a may be somebody in the forum haved similar ones.

1- We get a Alarm Error "emergency STOP" so we check the emergency stop button in the panel and working fine, so searching in the Diagrams we see
another emergency stop circuit wired with one single pole swich
directed to a one CNC I/O board, the swicht is named Kmon o some similar
(due the copy dont read weel the small fonts), the machine is equiped with a bar loader, but we not conect it yet..... may be a e-stop circuit from outside

2-We gat a LIMIT alarm. and the suspect is the lower turret in overtravel condition, Well we activated the OT swicht and make a reset, to jog the axis
to a safe position, but cant move anything so we suspect we need to
first leade the "E-stop" condition. is right?

how we can see the plc I/O signals in the CNC screen to see the i/O board staus?

Thanks a lot by the Help and sorry by my english


03-16-2009, 09:34 AM
I am sure that you must connect the bar feed unit before the system will function as a whole.
You should be able to "switch OFF" the bar feed unit, but I think it would be wired into the E-Stop circuit also... thus the reason you have an open e-stop loop.

03-16-2009, 10:14 AM
Hello Brian...

Well i suspect it!. so i not able to search the connection for the loader,
due are not in the wirings schematics. i try to trace the wirings and
connect it to see the results....i post also the results!

also i learn minute to minute the tricks in this machine!



03-16-2009, 06:32 PM
2-We gat a LIMIT alarm. and the suspect is the lower turret in overtravel condition, Well we activated the OT swicht and make a reset, to jog the axis
to a safe position, but cant move anything so we suspect we need to
first leade the "E-stop" condition. is right? End Quote

I am wondering how you get an alarm with a different alarm in the foreground?

Also with the overtravel-1.put the machine in Manual mode 2.flip the switch 3.Reset it 4.the alarm will change to something else I forget but the message will be different 4.only use the Jog handle, if you use the buttons the turret will not move.

But Brian is right the emergency stop alarm is going to have to be cleared before anything happens.


03-17-2009, 08:29 AM

Well. really a not have a "formal" LIMIT alarm in the CNC screen, only we get
a anunciator Blink in the Panel with the "LIMIT" word. so we see in the manual and fund "out of limit Axis"......

i see the very strange OKUMA way to make Electric Circuits plans. (i see similar ones in our Mori Seiki Machines but a lot more clear.) and at last i discover the KMON circuit. is the Relee used by close with 24V the E-estop circuit to the PLC input, due the e-stop loop is 110vac (for example in the eschematics the several poles of the relee is spread over the Sheet or Sheets, without any vinculation lines!!!!) due the loop is vinculated with the loader and unloader, just rest see in the panel, what is the points to jumps, so simulated the E-stop ok from the outisde machine.

Thanks a lot by the support


03-18-2009, 07:49 AM
hello again.

Well a able to restore the e-stop circuit without the Barloader attached.
a now a get another error, i suspect is part off the married lathe/loader.

The error is related to the Changeover Coil.....(in plain, the relee to make the change to hi-lo range is not actuated) this is for the right spindle, i see the circuit and discover the signal is not present to actuated the comand relee.
so may be i start a new post if need help abouth this new error.

thanks by the support


03-25-2009, 11:45 AM
we have okumas with barloader units. I don't know if they are the stock units or aftermarket but In our case you can switch system link off at the panel to end lathe to feeder communication and switch power to the feeder directly to eliminate the estop alarm on the feeder panel. A clamping device illegal is common. I dont know of the top of my head but on one or two situations simply switching off the alarm didnt help and we had to go into the parameters and change the b-x-+ limit var to a greater number to release the turret. This may have been for a larger diameter but its been about a year since i've seen it.

03-26-2009, 08:43 AM
well the problem a this machine in particular, is the barloader are not okuma, (is LNS )and as i can see the integration was done by a contractor by LNS, so in the center door, at the panel, is a cumulus off contact jumpers and relees, but it not documented in any way, so i need to discover the function off each by myself.
For now, we not need the bar loader, so i simply search the e-stop circuit and doing a wire jumper to simulate a closed circuit at bar loader.

after it the machine come to life, but i get several errors like "changeover" in the spindle (caused by a bad contact, in the contactor, and well ducumented in other thread), after solve it with the help a friendly guy, i get a alarm as the coooling spindle unit dont work, so i put in manteniance booth units, so i think tomorrow, try to "see" if can jog the axis, due is imposible to jog the machine, i suspect, first the all the alarms must be clear.

thanks by your info


04-04-2009, 06:47 AM
of course, shorting external Emergency Stop is proper solution in that case. concerning other alarms; it seems, they are all related to motors. Did You checked if power supply phase connection is proper? Did You checked the main supply voltage?

04-04-2009, 09:15 AM
hi sir.

Well the cooling circuit was shipped without a wire harness conected, but
i remove booth unit, to maintenance, due the machine is in painting work for now, until the next week. so after reasembly it i can perform more testing.

thanks by your support