Three Bad Habits of Electrical Technicians

Let’s face it; there are technicians who know how to diagnose and troubleshoot system faults, and then there are technicians who only know how to make guesses. Anyone who has ever worked in an industrial setting for any length of time has seen the difference. Anyone can blindly go through the motions and do the things that usually fix most problems—like rebooting a computer. But when the common solutions fail, you need a real technician who knows the art of troubleshooting. Here are some bad habits to avoid if you want to learn how to troubleshoot and do it well.

Swap-and-Pray

“I wonder if it’s the power supply. Let’s try replacing the power supply. No? What about the servo encoder? Have we replaced that yet? We have? Ok, what about the PLC? Sometimes those go bad.” And so on. The pseudo-technician’s typical strategy for fixing problems is to just try replacing one part after another until something fixes the problem. The sad part is that this often works; after all, parts fail. But if you don’t know why the part failed, you might not have addressed the underlying problem. It is not uncommon in these situations to find the same thing occurring again—and finding that a second expensive component has now been fried.

Meter-Poking

If you put a voltmeter on a terminal block, you should know what reading you expect to see. If you’ve actually diagnosed a problem and you have a working theory of where the problem is located, your meter should confirm or break your hypothesis. Some technicians—especially ones who don’t have much electrical experience, have a tendency to start poking around in cabinets, putting a meter here and there just to see what reading they get. It’s hard to say exactly why anyone finds this useful. The key to using a meter correctly is to first do the critical thinking about what reading would show up at which test points if the fault is where you think it might be.

Download it Again

Technicians who fail to understand how PLC’s and control units actually work have a tendency to look at them as mysterious black boxes. Sometimes, PLC programs become corrupt and need to be re-downloaded through a serial interface on a laptop. However, this is generally pretty rare. There are those, though, who develop a quick trigger finger for re-downloading PLC programs or firmware simply for lack of anything better to try. Sometimes, it’s a stalling tactic to buy more time to think. (In the field, when the customer is watching, sometimes it helps to be seen taking something apart or plugging a cable into a port just to ease their nervousness—even if you aren’t actually accomplishing anything). If you think that a PLC or PLC program is bad, first ask yourself: what output doesn’t make sense given the inputs applied to it? If you can’t answer that question, there’s probably nothing wrong with the PLC.

Being a technician is about critical thinking and observation. It’s not about blindly applying fixes that work a percentage of the time. You can get away with being a board swapper a lot of the time, but sooner or later you will find yourself in a situation where being a hack doesn’t cut it.

Tags: electrical, technician, trouble shooting

This entry was posted on September 10th, 2013 and is filed under Electrical, General, Technology. Both comments and pings are currently closed.