Student Discussion: How to Perform Residential Electrical Inspections Course

This open, public forum thread is dedicated exclusively to students currently enrolled in InterNACHI’s free, online How to Perform Residential Electrical Inspections Course .

Students may discuss course topics, ask other students questions, and share thoughts with other students.

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Hello

Will be starting this course

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studying for the test now, nice overview

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Great, @etancrell. Feel free to ask questions related to the course topics and share thoughts with other students.

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Thank you, @ematthews5. Feel free to reach out to anyone on the Education Team (Contact InterNACHI) for help with your training, certification, licensing, examination, or continuing education. They’re a great resource for you.

And feel free to ask questions related to the course topics and share thoughts with other students.

Looking at the cheat sheet in the introduction section under conductor sizes,

sizing conductor cheat sheet

I’m confused how to properly read this. It looks like the AWGS grow in size from the largest number to the smallest, until you reach aught 1/0. But then the aughts grow from 1/0 to 4/0 and then jumps to 300? At what point does each conversion happen, is 4/0 the highest and then 300 is lowest or how can I tell?

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The table starts out with wire gauge sizes commonly referred to as AWG.
Here that goes from #2 to #4/0, the ampacity of those conductors increase as you move down the table. Once you pass #4/0 then the condcutors are represented by their physical circular mil area which starts at 250 kcmils and increases in area as you go up in size.

The heading on this table should be changed to indicate that this can only be used for single family and dwelling units of two family or multi-family dwellings. It cannot be used for other services or feeders for other applications.

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Thanks, @rmeier2. Table content at InterNACHI® - International Association of Certified Home Inspectors has been updated.

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Awesome that answers it perfectly. Thanks!

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Ive taken the course and passed the test. woohoo

I finished the course and the exam but one thing that still isn’t clear to me is how service panelboard is properly grounded when it is located inside the home (not in a garage or adjacent to an exterior wall). I see many meter boxes grounded to 2 ground rods connected together under the meter box but how does the copper wire get to the panelboard when the home is a slab home and no other conduit can be seen running inside? Thank you

I am struggling to make sense of the second column. I get that the two right columns are to compare the wire diameters between Cu/Al at any given service amperage.
Is the “Solid Wire” column about the overall diameter of the SE cable at those amperages? Which doesn’t seem right- 150A SE cable at just over 1/4 in? Surely I’ve gotten something wrong!

That column is pretty meaningless because service condcutors large than #10 are going to be stranded so telling you a a diameter of a solid conductor is of little value. According to the NEC a #1/0 conductor has a diameter of .372".

When watching the:

Electrical Inspection Training Video With Paul and Ben

Right at the beginning of the video when descussing saftey equipment like glasses and gloves, they say that “Leather”, [like my skin…] is a non-conductive material???
I wonder if the cows know that? Possibly, they treat the leather with a product… but this seems highly suspect… And i would be interested to know what brand they recommend?

But the most concerning aspect of the video is how often they are putting their fingers in the panel and handle the supposedly energized items… Bare handed, continually, without end. If they had at the very least, killed the panels power, at the main service disconnect.

As a student, having a check list of the defects, on the same page as the video would be helpful for me to recognize defects, right there, as they are identified. It might also be useful to include the precise reporting language describing the issue. As you would use in the report. It is one thing to teach us to identify the issue and explain why it is an issue… but that is not what i would put in my report. How should i describe the defect in my report?

“Well gee mister… since they were supposed to do X-Y-Z and they didn’t, its not installed properly and needs to be fixed by a qualified trades person… Because it’s a safety hazard. And I’m gonna be checking my “major defect” box. 'Cuz it’s serious.”

There could be some examples described with professional language all the way down the checklist. I would find this helpful. As i tend to ramble on… Description appropriate/ Precise terminology for the defects listed would be greatly appreciated. Who’s up for the challenge?

Panelboard Inspection Checklist

  • Take inspection images for every task of the inspection process.
  • Wear personal safety protection, including glasses and gloves.
  • Touch the panelboard cabinet and front cover with a non-contact voltage detector.
  • Check for adequate workspace, clearances, and illumination at the panelboard.
  • Read the label on the cabinet front cover to identify the cabinet name and type.
  • Check the condition of the dead front cover and for proper fasteners.
  • Check specific identification for all breakers.
  • Check for inspection stickers and dates.
  • Check for unused openings, including knockouts.
  • Identify the main service disconnect and rating, if labeled.
  • Identify the breakers in the “off” position.
  • Remove the dead front cover safely and carefully. (Not required. Optional. Hazardous.)
  • Gaps greater than 1/8 inch between the cabinet and wallboard are not permitted.
  • Check for rust, corrosion, or water inside the cabinet.
  • Foreign objects or contamination inside the cabinet are not permitted.
  • Check service entrance conductors and main lugs.
  • Check clamps, connectors, and bushings.
  • Check for disconnected or loose conductors.
  • Inspect the main bonding jumper.
  • Inspect the grounding electrode conductor (GEC).
  • Locate and follow grounding and bonding components.
  • Check the material type of the main water supply pipe.
  • Check for damage to wires or sheathing.
  • Check for melted or scorched conductor insulation.
  • Check for overfusing or oversized breakers in relation to the connected wire gauge.
  • Check for loose equipment grounding conductors.
  • Check for doubled neutrals and doubled hot conductors.
  • Look for multiple wires under a single screw at the neutral bus bar.
  • Look for different gauge wires under a single screw at the grounding conductor terminal bar.
  • Check for solid conductor aluminum branch-circuit wiring.
  • Identify any breakers that are not permitted by the manufacturer.
  • Check for identified handle ties.
  • Test GFCIs and AFCIs with test buttons.
  • Check multiple cables in connectors and clamps.
  • A doorbell transformer inside the cabinet is not permitted.
  • In the subpanel, confirm that the EGCs (equipment grounding conductors) are on a separate terminal bar that is bonded to the cabinet and that the grounded conductors (neutrals) are isolated or floating from the cabinet.
  • Never leave the panelboard exposed.
  • Replace the cabinet’s dead front cover immediately, correctly, and safely.
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Google Article 100 and you’ll get precise terminology used by the NEC.

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Unrelated questions
[Perhaps my questions are ahead of the regulating bodies paperwork?]

  • If Aluminum wires require antioxidant paste when connecting to copper in a splice situation. Why don’t aluminum lugs in the terminal bars require antioxidant paste when copper wires are inserted and fastened into them with a lug? It’s dissimilar metals with galvanic potential…

  • Is there a situation when aluminum feeders DO require antioxidant paste plugging into an aluminum lug?

  • Isn’t there a Galvanic potential when mounting Aluminum Terminal bars to a “galvanized” steel cabinet? Or does the Galvanizing process eliminate galvanic potential? What about the bonding strap or the Grounding electrode conductors? It too is dissimilar metals with galvanic potential…

Just curious…
It seems to be an across the board principle that has only partial application.

Starting course.

Starting this course now. Will come back during or at the end if there are questions!

Thanks, @apolanco2.

Good questions, @acrowell3. Inspecting the Main Electrical Panelboard During a Home Inspection - InterNACHI® touches a little bit about antioxidants you may want to check out.

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