About tapping the panel cover with the knuckles to ensure that panel is not hot

You could use both I presume. I believe its a holdover to listen to the rattle and hum.

Sometimes it’s pointless to point out errors :confused:. Life’s too short. :laughing:

I was teaching the InterNACHI electrical class. I made the corrections at the request of the InterNACHI school director. They wanted me to use the InterNACHI Electrical book as the course textbook but the book was rife with errors. I covered the material but had to do a lot of explaining to the students. As I said in an earlier in an earlier message, there are multiple questions on just that one page that have incorrect answers as the correct one.

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Hi George, that was the kind of answers I was looking for in this post. Now, if I come across this question on the state exam, what answer you think they will accept as correct, regardless what the InterNACHI’s practice questionnaire says?

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That’s why I don’t think I can justify paying for classes :thinking:. Too much misinformation seems to be included.

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One would think they’d want to correct the errors. :man_shrugging:

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That question seems like a common sense question. I certainly hope there is no test that says it is appropriate to use any part of your body to check for Voltage.

I am more concerned about the questions such as the one that says feeders can’t be spliced, the one that says a weatherhead needs to be three feet above the roofline, and the one that says conductors between two panels must be in rigid conduit and have overcurrent protection at both ends. All those questions have incorrect answers as being the correct answers. If a person doesn’t have an electrical construction background, they would have no reason to doubt the correctness of the questions and answers.

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I can understand your concerns. Unfortunately, you are not likely to get a good quality electrical course through any home inspection school. It is sad because residential electrical systems are really very simple. If a person doesn’t have a thorough understanding of residential electrical systems, it will be impossible to gain an understanding of commercial electrical systems.

Too much of the electrical training in the home inspection world involves random and disjointed code excerpts instead of how electrical systems actually work.

I suggest avoiding electrical textbooks that focus on codes. Instead, study from books such as “Practical Electrical Wiring” by Richter and similar books. There, you will find good practical explanations of how electrical systems are built and some of the rationale behind their design.

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I agree, I have a good understanding of the residential except for when it comes to feeders and subpanels.
Commercial work I’ve been involved in was at many times too complicated for anyone except for a certified electrician who went by our schematics and sometimes those were not accurate.
I do know my limitations and weaknesses. I am very weak when it comes to 3 phase systems. I know the basics but Commercial work is usually hacked together.
I wanted to see what the real world approaches were. And as you said not rely on codes.

I was a mechanic the electrical technician would always say no that’s not how it works. But that was it. :laughing: I was taught by people that really didn’t know too much themselves.

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I still have my first one, George!

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If I used my chirper/ticker it would go off/beep every time due to the breakers inside.

Why wouldn’t they suggest a non contact voltage meter? I guess knuckes is better than fingers

wait until they start asking questions about a picture that is out of focus

Technically… it is “back of hand”, NOT knuckles!

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What about the tried and true method of whizzing on it?

Because it will often go off even if nothing is wrong.

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This article was pretty good without being terribly technical.

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Not a good article about voltage testers. In one of several assumptions made by the author, “There may be some conditions where a voltage sniffer will fail to detect current if you’re not actually holding the device, as shown in the clip below.”

Even a basic understanding of the workings of these voltage sniffers includes the fact that your body is an essential part of the capacitive coupling. Simply stated they aren’t supposed to work if your not holding them.

For a definitive article on the mysteries of “voltage sniffers” read:

or

https://www.ecmweb.com/content/article/20891439/what-do-you-know-about-capacitive-voltage-sensors

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They will ALWAYS fail to detect current because that’s not what they do. They detect Voltage, not current. Anyone who doesn’t know the difference between Voltage and current shouldn’t be writing any electrical articles.

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