Any good troubleshooting books available?

[Sparky up north]

Hello all,
I will be applying for a job soon that will require a lot of troubleshooting type work. I have several years experience in residential and light commercial electrical work. My trouble shooting skills are definitely lacking. Can anyone direct me to a online course or possibly a good troubleshooting book? Any information is appreciated.

 

[gar]

220130-0539 EST

Sparky:

I don't think you need a book. You need a basic understanding of basic electrical theory. Then you from your experience, in the field of work you do, you develop techniques to solve your type of problem.

You need to learn about voltage and current sources. Resistance of materials, types of loads, and what happens when you combine these.

You need to determine if your source is good, or what its characteristics are if not good. You need to understand your load characteristics, You need to study the impedance between the source and load. You need to know how instruments work, and their limitations.

Then you need to figure out how to get part way into a system to determine which way to go looking for the problem.

I have no way to know where you are starting from.

What kind of problems do you not understand?

For example:
In a residential application how much voltage drop typically occurs at the main 120 V lugs when you apply 120 V 12 A load to that circuit? What happens to the opposite phase?
What is the resistance of 100 feet of #12 copper wire?
What is the peak starting current to a1/3 HP 120 V induction motor? What is the RMS value? At a minimum how long might this last?
What is the peak inrush current to a 100 W 120 V incandescent bulb when turned on at the peak voltage point? How long is its duration?
How does the voltage drop on a neutral wire compare to a hot wire of the same size and material?

The above are just a few simple questions, but might allow you to solve many problems.

.

 

[Fred B]

Like Gar said, an understanding of how and why things work, and what a working system "should look like" when functioning properly are a beginning to troubleshooting. Then from there taking logical steps backward to source of problems. Then knowing how to correct once you find the problem source is the final step. I've seen guys just start throwing parts at an issue then after a lot of money spent either give up or find what was really a simple problem. This not limited to the electrical field but have seen in mechanics, plumbing and appliance, any area where troubleshooting is involved.

Experience over time is a big part of simplifying your troubleshooting tasks, many issues will present in a specific fashion and your experience will point you to a fix quicker without having to rip everything apart, this part cannot be learned from a book, and is an ongoing learning curve. A good source while not comprehensive but gets into a lot of "real world" application of troubleshooting is this forum under troubleshooting. Look through that and see how the logic forms (most times lol). Another piece is the homeowner or machine operator or whomever is reporting the trouble, always lies (or leaves out key parts of the picture) so experience is key to "trying" extract needed information for troubleshooting. 90% of the time, on trouble calls will eventually at some point find something the owner deliberately or absentmindedly neglected to mention when I was first asked to look at the issue.
If you are going to be dealing with mostly specific equipment, getting the service manual (if there is one) would sometimes give a step by step trouble diagnostic methodology for that equipment. That doesn't replace basic knowledge though.

Don't know your electrical background or if you are licensed and what level, but if your prior employment didn't provide the opportunity to learn that phase of electrical work (troubleshooting) during your apprenticeship, jumping straight into a troubleshooting role will be like trial by fire. Mike holt has some good publications that go into basic electrical theory that you might be benefited by "IF" that is where you are lacking. I know of a lot of EC who get apprentices and never have them learn theory only the mechanics of the trade, and these guys will struggle with troubleshooting. Early on I work for one of those types and had to learn theory kind of backwards, learning (and still learning) after the mechanics.

 

[hillbilly1]

Don’t know if your experience has been new, ground up construction, but that is one of the best ways to learn troubleshooting. If you know how it was put together to begin with, it makes it a whole lot easier to troubleshoot. The journeyman I started out with, had a saying when troubleshooting somebody else’s work, “If I was an idiot electrician, what would I have done?”LOL!

 

[Sea Nile]

Ditto what everyone else said. No shortcut to true trouble shooting. If you could follow a flow chart to find the issue then you have no job security.

Understand the fundamentals and you should be able to think about why it's not operating normally.

If you ever find yourself "shotgunning" a problem, you should walk away and clear your mind.

 

[RCC1]

220130-0539 EST

Sparky:

I don't think you need a book. You need a basic understanding of basic electrical theory. Then you from your experience, in the field of work you do, you develop techniques to solve your type of problem.

You need to learn about voltage and current sources. Resistance of materials, types of loads, and what happens when you combine these.

You need to determine if your source is good, or what its characteristics are if not good. You need to understand your load characteristics, You need to study the impedance between the source and load. You need to know how instruments work, and their limitations.

Then you need to figure out how to get part way into a system to determine which way to go looking for the problem.

I have no way to know where you are starting from.

What kind of problems do you not understand?

For example:
In a residential application how much voltage drop typically occurs at the main 120 V lugs when you apply 120 V 12 A load to that circuit? What happens to the opposite phase?
What is the resistance of 100 feet of #12 copper wire?
What is the peak starting current to a1/3 HP 120 V induction motor? What is the RMS value? At a minimum how long might this last?
What is the peak inrush current to a 100 W 120 V incandescent bulb when turned on at the peak voltage point? How long is its duration?
How does the voltage drop on a neutral wire compare to a hot wire of the same size and material?

The above are just a few simple questions, but might allow you to solve many problems.

.

I liked the part about either knowing or knowing where to find the information you need. I always tell students to think about what they would expect the meter to read before touching a probe to any point in the circuit. If they do not know what they expect the meter to read, there is no value in the reading it.

 

[kwired]

Electrical theory knowledge is biggest asset.

Some mechanical knowledge sometimes can be pretty valuable as well- if troubleshooting tripping motor overloads a majority of time the problem is not electrical, but owner/operators figure since it is an electrical device that is shutting things down it must be an electrician's problem to solve, but in reality you are going to have to prove why they are overloading the machine and the overload is just doing what it was supposed to do.

Experience is the next biggest asset. Some that theory just doesn't fully sink in until there has been experiences in seeing how it really works.

 

[LarryFine]

Electrical theory knowledge is biggest asset.

Experience is the next biggest asset.

Agree completely. Trouble-shooting probably relies on instinct more than any other facet of electrical work.

The basis is that the circuit or system was working, something has changed, and you need to figure out why.

 

[hillbilly1]

Ditto what everyone else said. No shortcut to true trouble shooting. If you could follow a flow chart to find the issue then you have no job security.

Understand the fundamentals and you should be able to think about why it's not operating normally.

If you ever find yourself "shotgunning" a problem, you should walk away and clear your mind.

Just love talking to customer support in India when troubleshooting. LOL! They go by a troubleshooting chart, and do not deviate. So instead of a five minute fix, you have to go through 30 minutes of bad English to get to a resolution (usually software errors) Finally they will escalate it to someone that kinda knows what they are doing, and they correct the software error. They always blame the electrical, even though you have manually bypassed their system, and it works.

 

[synchro]

Hello all,
I will be applying for a job soon that will require a lot of troubleshooting type work. I have several years experience in residential and light commercial electrical work. My trouble shooting skills are definitely lacking. Can anyone direct me to a online course or possibly a good troubleshooting book? Any information is appreciated.

I think it would be helpful in your case to focus on the types of installations and equipment that you would be dealing with on this particular job. Basic electrical knowledge will be needed in all troubleshooting, but residential, commercial, and industrial will need different knowledge and skills (including dealing with customers). If you can give more informaton about the type of job, then I think that forum members could give you more specific information for training recommendations.

 

[zbang]

A couple more things-
Ask yourself "Did it ever work correctly?" or "It might have looked correct, but was it really?" Usually the answers are yes, but sometimes..... (I had one of those a few months ago- somebody used a traveler leg from a 4-way to power the the e-light battery pack.)
From knowing both electrical theory and how things are commonly wired, be ready to ask yourself "What sort of hare-brained idea could somebody have done to make it work this way?" (see above )
Never dismiss the possibility of a nail through the cable.

When things get complex, make notes and sketches of what you're finding; that'll help keep you from trying the same thing multiple times and can often turn up missing pieces of the puzzle.

 

[OldBroadcastTech]

May I add to all the above:

Learn to break the problem down into manageable 'chunks'.

Example: the light doesn't come on when the switch is 'ON'.

( I guess maybe substituting a known good lamp might be the first step, but anyway....)

Break it as close to half-way as possible, for example, at the load side of the breaker........do you have voltage on the load wire no matter what the position of the switch? stick a known load on it ( 100 W lamp, drill, etc), do you still have voltage ? if so, you have eliminated everything 'upstream' as a possible cause.

Then break the remaining half in half........say at the switch terminals

I think you can all see what I'm trying to say.

Oh, and NEVER go into troubleshooting a problem with a pre-conceived notion of 'what might be wrong'.........trust only what you can see and verify (and don't always trust your meters, etc; more than once 'they' have let me down.......)

Thank you all for your patience

 

[hillbilly1]

May I add to all the above:

Learn to break the problem down into manageable 'chunks'.

Example: the light doesn't come on when the switch is 'ON'.

( I guess maybe substituting a known good lamp might be the first step, but anyway....)

Break it as close to half-way as possible, for example, at the load side of the breaker........do you have voltage on the load wire no matter what the position of the switch? stick a known load on it ( 100 W lamp, drill, etc), do you still have voltage ? if so, you have eliminated everything 'upstream' as a possible cause.

Then break the remaining half in half........say at the switch terminals

I think you can all see what I'm trying to say.

Oh, and NEVER go into troubleshooting a problem with a pre-conceived notion of 'what might be wrong'.........trust only what you can see and verify (and don't always trust your meters, etc; more than once 'they' have let me down.......)

Thank you all for your patience

Also known as divide and conquer! LOL!

 

[LarryFine]

Additional tip: Use a solenoid voltage tester, not a voltmeter, when you want to test for the presence of real power, not for a specific voltage. My favorite is the Knopp K60:

 

[synchro]

If the problem and fix isn't obvious it can help to note down what works and what doesn't, any voltage and current measurements, etc. Also, you can take pictures of the wiring and installation with your phone. Then you can review how different explanations for the problem match up with what you've observed. And if you're still stumped you can post the info here so that we can give you some help.

Also, along the lines of what hillbilly1 said in post #4 that an "idiot" electrician may have preceded you, don't assume that everything has been safely wired until you can confirm this with measurements.

 

[zbang]

This is a place where the Fluke T-pro+ shines- not only is it a low-impedance tester like the Knopp (which are also great), but it will also show continuity without changing settings; there have been more than a few times when I put probes on some terminals expecting to find 120v and found that they were somehow connected instead (and shouldn't have been). Sure, some loads will confuse this, but knowing what to expect and finding something different is part of troubleshooting.

 

[hillbilly1]

And any information the customer gives you, take it with a grain of salt! I’ve had outlets the customer swore worked at one time, only to find out, it was never connected! Someone never finished the job when the building was built. Do find out if somebody was there before you, especially if you work on parking lot lights. I’ve came behind people that just start swapping wires in the poles, hoping something would start working. When that happens, it’s usually easier to just start over, and reconnect everything from scratch.

 

[LarryFine]

This is a place where the Fluke T-pro+ shines . . . it will also show continuity without changing settings; there have been more than a few times when I put probes on some terminals expecting to find 120v and found that they were somehow connected instead (and shouldn't have been).

"How do it know?"

I'd be concerned about being confused by a tester that responds to different conditions.

 

[ActionDave]

"How do it know?"

I'd be concerned about being confused by a tester that responds to different conditions.

The fluke t+ acts a lot the same as my fluke 12. I'm as fond of my fluke 12 as you are of your knopp. I'll wager the reason for both of us is the same, in that I'm very familiar with how my tester responds in most every situation.

 

[Sparky up north]

I originally thought my post was a dud, since it did not receive a response right away. But thanks to everyone that has responded.