ML1400 Fault code 0x0008h Major Error

I have a MicroLogix 1400 1766-L32AWAA controller. I got everything out of the box today and connected the power, it powers on, set to DHCP and everything is good. The unit has 120 VAC I/O, so I jumpered the neutral to COM 0-3, and then touched the hot to one of the inputs, IN3 or 4. I saw nothing on the I/O Status page and then upon touching the wire again, it sparks and trips the breaker. Of course now I start the controller back up and fault is blinking red. I'm in the status file and it reads the error code 0x0008 major error.

I'm assuming I fried the damn thing and I just need to buy another one (just great ).

I thought I knew a thing or two about electronics here...COM in regards to AC refers to neutral, yes? And then the input will be a hot, to complete the circuit. What the hell did I do?

Thanks for any answers.

Check out the AB knowledgebase article #450490

It says a 08 error could be software related. Do you have a program loaded? Try reloading the program. It also says check grounding and surge suppression.

It doesnt sound like what you did could have killed the PLC.

Thanks for your response. Like I said I just got it out of the box and hooked it up to wall power. Didn't load anything onto it. Now the ethernet port doesn't seem to work, so I can't even attempt to load something on it.

What you describe is correct; the "COM 0", "COM 1", "COM 2" and "COM 3" terminals on that controller are supposed to be connected to "L2", commonly called "AC Neutral".

There is a wiring diagram on Page 50 of the User Manual that illustrates how the Inputs on that controller are grouped into four separate groups. On most systems, L2a,b,c,d are going to be the same "AC Neutral".

If there was a short to ground through an Input circuit, I would insist on a warranty replacement. Most distributors, if you can illustrate convincingly that you connected the controller correctly, will accept a warranty claim.

I got the code to clear after switching the mode to run and then back to remote, but the ethernet port still doesn't seem to work. I was told to power off and disconnect the battery, did that and now it's reading error 0x0001h.

Guess I'm going to try pleading with the distributor.

Isn't there an Enet config screen on the front panel under Advanced setup?

Yes, and changing the settings does nothing. Before I just changed it to DHCP and it quickly took 192.168.0.42 after a power cycle. Now nothing works. Tried a static IP as well. The lights on the ethernet port aren't even lighting up so I just think it's dead.

Spark

When ever spark happen in controller due to power supply then its means some circui are surly damaged. In your case it is ethernet card

where was the ground for your PLC and computer hooked to? It is never good practice to use a live wire held in your hand to simulate inputs, too many things can go wrong, small terminals loose strands of wire ect... Did you try using the boot p again? check the comms on the PC? does the LCD display still show an ip address?