Need Help!- bridgeport TC-1 errors

[brian448]

The machine has been running decent for about a month now... since we last had it worked on. Suddenly, it is giving three different errors. The first to pop up is a "coolant motor overload", followed closely by a "Emergency Stop Activated" message. Two things... the coolant motor is not in use and no one has hit the emergency stop button. A third error did come up but only once so I am not sure it is significant or related in any way to the other two errors which come up each time the machine is turned on. I am new to this machine so am not at all familiar with it. If anyone has suggestions on what the issue could be... or issues. Please let me know. Thanks!!

-Brian

[machintek]

Check your 24VDC power supply.

George

[brian448]

I was looking into that... reading the manual. The manual says to check wires 31-32 and that they are located on CB4. That is not the case. There are a buch of 31's together in the overload section right next to a bunch of 32's. The only place I see 31 and 32 meeting is where it plugs into the MCP box. With the machine running, I did check the voltage at that plug and it was reading little to nothing... fluctuating. On the 24 VDC power supply mounted on the left wall, I checked the voltage coming in and it was ( I believe correct) 115VAC. On the opposite side, I checked for VDC and it read similarly to what I saw on the 31-32 wires but a bit higher... still fluctuating in time with the little LED light which was blinking. I am not sure what, if anything that means.

Is this any help in diagnosing the problem?

[brian448]

As I mentioned earlier, the 24VDC power supply LED light blinks rather than stay steady. I disconnected the wires coming out of the power supply and the light was bright and steady. I put the wires back and flipped off the CB5 with wires 30 and 31 in it. Again, the light on the power supply went bright and steady. What I also noticed is it is directly corresponding to the 3 circuit boards on the back wall... tool changer I/O board and input and output boards. The lights on those are blinking in unison with the power supply LED. So is this normal? It would seem that a power draw is causing the emergency stop activated error because the circuit is not completing like it should. The relays down the line from the motor overload 1 and 2 SEEM ok. Nothing obviously burned out and I gave them each a pretty good tapping in case one was stuck but no changes. What could be causing this power draw? Could the power supply be going out and just not capable of handling the load anymore?

Thanks, George, for your earlier response. I hope you can gleen some useful info from this post and help me a little more. Or anyone else here for that matter.

[ppascuzzi]

Originally Posted by brian448 As I mentioned earlier, the 24VDC power supply LED light blinks rather than stay steady. I disconnected the wires coming out of the power supply and the light was bright and steady. I put the wires back and flipped off the CB5 with wires 30 and 31 in it. Again, the light on the power supply went bright and steady. What I also noticed is it is directly corresponding to the 3 circuit boards on the back wall... tool changer I/O board and input and output boards. The lights on those are blinking in unison with the power supply LED. So is this normal? It would seem that a power draw is causing the emergency stop activated error because the circuit is not completing like it should. The relays down the line from the motor overload 1 and 2 SEEM ok. Nothing obviously burned out and I gave them each a pretty good tapping in case one was stuck but no changes. What could be causing this power draw? Could the power supply be going out and just not capable of handling the load anymore? .

Power supply could be going out or something else could be shorting out. The main 24 volt power supply in the TC's usually had a 5 amp circuit breaker or fuse protecting it's output and should be able to supply 5 amps with out problems. If your's is the same and you have access to a 5 ohm 150 watt (or higher wattage) resistor you could put it across the output of the power supply (disconnected rom the rest of the machine) and see if the green light stays on and if 24 volts is being output under load. The resistor would draw about 4.8 amps. If your power supply has a label on it saying what it's output is use those figures to calculate the resistor needed.

If the power supply is good you'll have to try to find the short. Could be a shorted prox switch or a bad cable someplace.

[brian448]

I just disconnected the 24VDC wires going into the I/O board. I turned on the machine and ALL the lights (except the I/O board of course) were bright and steady. If I understand the wchematics correctly, the wire goes from TB1 to the I/O board. So possible break in that wire? I'll be checking it out shortly. I did the same thing for the other two circuit boards and with the 24VDC wires disconnected. It had the same problems as before. So I am sure that what is causing the drain is either in that wire to the I/O board or the board itself or it could be something after the board, but I have not gotten to that point yet. If it is a straight wire from the TB1 to the I/O board, I should be able to jumper it to verify the wiring. I'll update again as I get more info. As always, input from you folks is very welcome.

-Brian

[brian448]

I ran jumper wires to the I/O board bypassing the possible broken wires and had the same result so I do not believe there is a short in the wires going to the I/O board. Therefore, it has to be something on the board itself doesn't it? I was thinking maybe a wire leaving the I/O board on the other side might be shorted but how likely is it that a wire can develop a short without ever being moved? My gut is telling me it is the board itself having a problem. Any thoughts?

[ppascuzzi]

Originally Posted by brian448 I ran jumper wires to the I/O board bypassing the possible broken wires and had the same result so I do not believe there is a short in the wires going to the I/O board. Therefore, it has to be something on the board itself doesn't it? I was thinking maybe a wire leaving the I/O board on the other side might be shorted but how likely is it that a wire can develop a short without ever being moved? My gut is telling me it is the board itself having a problem. Any thoughts?

It's a possibility. The power leads are not the only ones that carry the 24 volts, this is also what powers the prox switches and other switches that are on the machine, some of the cables to those switches do move as you run the mill. If I remember right the i/o of the board is all on plugs. Check the prints and see which you can unplug and see what happens.

[brian448]

Ok, I disconnected all of the wires going into the tool changer I/O board one at a time until I found the culprit causing the power drain. The I/O board is fine.. at least it appears so. The offending wire is on JP1-4. Listed as wire 31 which is a 24V power wire. I tried to physically trace the wire to its opposite end but it is lost in a wire bundle going into the machine. According to the wiring diagram this wire goes through a switch for "Tool Unclamped" then around to become wire 151 at JP4-4 I/O 51. My gut hasn't been right so far but I am now thinking the switch is the likely issue. I will post an update when i know more.

[ppascuzzi]

Originally Posted by brian448 Ok, I disconnected all of the wires going into the tool changer I/O board one at a time until I found the culprit causing the power drain. The I/O board is fine.. at least it appears so. The offending wire is on JP1-4. Listed as wire 31 which is a 24V power wire. I tried to physically trace the wire to its opposite end but it is lost in a wire bundle going into the machine. According to the wiring diagram this wire goes through a switch for "Tool Unclamped" then around to become wire 151 at JP4-4 I/O 51. My gut hasn't been right so far but I am now thinking the switch is the likely issue. I will post an update when i know more.

Typically they used just a roller switch for tool clamp/unclamp. Unless the switch is physically damaged they normally fail by either staying open all the time or closed all the time but not shorting out the supply. My gut feeling would be that the wire is shorting to ground some place. Since the cable moves up and down with the spindle it does get flexed a lot. Once you get the covers off if the switch looks intact just disconnect it (make sure the wires don't touch the frame--maybe put some tape over them for now) Turn the power back on and see what happens...if it does come up move the spindle up and down some and see if it goes out again.