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Control wont stay on

camaro_dan67

Cast Iron
Joined
Dec 4, 2009
Location
N.E. Pa.
I have a Fanuc 3m model c on my mill and if anyone on here has been following my posts I've been having some problems with it. I just installed a different motherboard on it. I got everything connected and started it up this afternoon to the point where the control was on but the estop was in. I entered all my original parameters then shut the machine off to restart it. When I went to restart it the control would only come on if I held the ready button down. I rigged some boards to hold the ready button in so I could check voltages. Coming out of the power supply it has 5 volt 24 volt and + and - 15 just like it should. There are several relays on the door and some contactors in the cabinet. I thought I remembered when I turned the power on then pushed the ready button I would hear one click and the power supply fan would come on along with the screen lighting up then I would release the e-stop and push it again and hear a larger clunk like a contactor engaging. I think the second clunk was turning on the servos. I do have a so so wiring diagram from the machine builder but its vague. Is anyone familiar with the startup sequence of the older Fanuc controls? Thanks Dan.
 
I just went through something similar on a 3T (see the Yang/Yam) thread. There is a relay on the power supply that closes if the power supply monitor chip thinks everything is OK. The relay (if the same supply) outputs are right next to the two 220 AC voltage inputs and are labeled PA and PB.

If you've got the button held in, take an own meter and measure if those two blades are short or open.

On my machine, the relay had stopped working (hadn't been run in a loooong time), and eventually started working correctly.
 
Look at the electrical ladder and make sure any relays or contactors required for latching are working correctly. On my old 6T the lubrication pump contactor was dead and that was required to latch the control power on.
 
Is it possible I entered a parameter wrong? I read somewhere else that parameters around the 900 numbers in these controls affect the way some of the relays behave. Is this true? It seems strange to me that I connected everything and the control started and was on and working up until the point where I entered parameters then after that I turned off the parameter enable switch and restarted the machine and thats where the problem started.
 
900 series are option parameters. If you tried to turn something on that lacks the hardware or otherwise entered them wrong you may have the wrong keep relays active at the wrong time.
 
I have solved this issue but there is still one more. This issue was caused by a single contact breaker not closing. The machine tool manual I have shows contact breaker 5 closing to provide power to the DC operation circuit power source. It simply was not letting power through to the diode pack that made the power for the control.
Ok now for the other problem. The control comes up and with the E-stop still in it displays NOT READY. This is normal. When I release the E-stop I'm supposed to push the ready button again and I think the servos power up. When I do this the head of the machine wants to take off at 900mph straight towards the table. Luckily I have a 2x4 in-between the two and it stops this. The z velocity control unit then throws an ovc alarm which is expected because the board stopped it. What is causing this? There are no alarms if the machine sits in the not ready state with the E-stop pressed. The spindle drive has a green light next to the PIL marking. The motherboard has a single green led and the crt is simply flashing not ready.
 








 
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