Gain the knowledge and confidence to inspect a home’s electrical system in this free three-hour webinar. You’ll learn how to evaluate the service entrance, grounding, and key electrical safety issues—plus how to spot common defects that could put occupants at risk. This training will help you deliver thorough, accurate, and safety-focused electrical inspections every time.
The video has too much misinformation. InterNACHI should have an expert review videos before posting them. It’s ironic that the narrator says inspectors should use proper terminology but he misuses terms and makes up words. He gets basic stuff wrong. For example, at 18’10” he says a #3 conductor is pronounced “3 aught”. That’s wrong. #3AWG and 3/0 (3 aught) are two different wire sizes. He says the same thing later in the video about #4. He says that #4 is pronounced 4-aught. Again, #4 and 4/0 are two different gauges. He repeatedly refers to “Amplicity”. Amplicity is not a word in the English language. At 22’35” he says “#14 should not be connected to a 30 A breaker. Why? Because of the resistance is going to be too much”. Seriously? That, of course, is wrong. At 23’14” he says “Ohms (mumbles) and that has a Greek symbol which I believe is god”. It is not a Greek god. At 31’52” “Ground is bonded to the panel and it is isolated from the neutral”. That is a misconception that is common among home inspectors and poorly trained electricians. They are not isolated. The grounded (aka neutral) is always solidly grounded. That fact can easily be verified with a continuity tester. “Isolated” means there is no conductive path, which of course, there is a conductive path. Otherwise there would be a floating neutral, which would create problems. There’s no excuse for an electrician not to know that. His explanation of why aluminum conductors are larger for a given ampacity is wrong.
I only watched about half an hour of the video. After the first half hour, I randomly jumped ahead to several different points in the video. I found incorrect information at every point. The video should be taken down. It is doing more harm than good. Bad information is worse than no information. Home inspectors, especially new inspectors, look to InterNACHI for accurate information.
@dhouglum, I tried to verify your credentials as an electrician in both Florida and Minnesota online search portals, but all I could find was your Florida home inspector license.
You said that you’re an “electrician by trade”, but have you ever practiced as an electrical contractor? What is your experience in the field?
I completely understand the question — and I appreciate you taking the time to look into my background. I have a 2-year degree in electrical and also completed vocational training during high school. While I never pursued a state electrical license, I worked hands-on in the field through a non-profit under Jim Green, where I gained valuable practical experience. My mentor, Perry Vogler, who is close friends with Mike Holt, has also been a major influence on my electrical education and approach to safety.
When I refer to being an “electrician by trade,” it’s because electrical work has been a core part of my training and background, even though I transitioned into home inspections professionally. My focus now is applying that electrical knowledge to ensure safe and thorough inspections for my clients.
I guess being an “electrician by trade” is subjective. In GA, you can be an electrician without a license, but you must work under a licensed electrical contractor.
So, you’re a home inspector with electrical background. You should stick with that. Making the claim that you’re an electrician and botching basic terms diminished the credibility that you were trying to establish. It made you look, well in your words, “inexperienced”, “unprofessional”, and “bad”.
I get it that it was a live webinar and you got tongue tied a couple times. I know that you didn’t mean to say “porpoises” instead of purposes; and I really hope that’s what happened when you said “amplicity” instead of ampacity. I’m also thinking that the Greek God comment was a just a bad attempt at being funny.
That is a sub panel. The grounding conductors and the grounded conductors are not connected there. They are “isolated” from each other in that panel. The grounded conductors are solidly grounded at the service entrance with the grounding conductors (single point ground), but kept separate until they are united at the service entrance.
I have formal college level training in HVAC, but I’ve never called myself a mechanical contractor. Though, I was a service technician for a while but I grew tired of the expectations from my employer to bait and switch customers.
I have also been an “electrician’s helper” off and on for the last 6 years, but I’ve never intended to pursue apprenticeship. So,I’ve never referred to myself as an electrician. Maybe I should. We are finishing up the first of two new construction single family homes next week.
It is a long video. I have watched about half of it. There are at least two other videos imbedded in it. I found nearly all the information to be accurate and useful. I agree that 14AWG is not matched to a 30amp breaker because of resistance although broadly speaking, “resistance” is a part of the explanation and using that term requires extended explanation.
I smirked when Dirk said something about Ohms and a Greek god, but since HIs almost never report on ohms, that was a “so what” for me.
“Amplicity” went by me. I guess I was thinking ampacity and that is what I heard. That might be a regional term for Dirk.
Dirk said several times in the video that…using correct terminology is important (I agree) and he made a mistake.
Hopefully, Dirk will respond to these comments.
In general, I am pretty forgiving on these videos of minor mistakes. I’ve made a few of these and I made one particularly incorrect statement in one of them that annoys me to this day. It’s hard to be perfect. I look at this like, “Should perfect be the enemy of good?” I thought this is a good presentation. But I am definitely interested in what others think. Hopefully, some of you other guys and gals will take some time to watch some or all of it and post your thoughts here.
You contradicted yourself. They can’t be both isolated and connected together. As I said in my original comment, this is a misconception that many home inspectors and poorly trained electricians believe and spread around. Isolated, in the electrical world, means no conductive path. There’s another active discussion on this message board about the topic. Another InterNACHI member used ChatGPT as his defense for misusing the word “Isolated”. I went to ChatGPT to find out why it gave him conflicting information. ChatGPT acknowledged that it had improperly used Isolated in a narrative. It did so because it got that from unqualified sources. You can view the entire conversation. I posted the link to it.
The grounded conductor is always solidly grounded. If it weren’t, you’d have a floating neutral (another term frequently misused by home inspectors and poorly trained electricians), which is a problem. The fact that they are not isolated (because there is a conductive path), can be verified with a simple continuity tester.
Part of the problem we have in the home inspection world is that much of the misinformation has filtered down from residential electricians. It doesn’t take much to be a residential electrician. In many areas, it is only a two-year apprenticeship. Residential electricians have limited exposure to electrical systems. While a residential electrician can get away with using incorrect terminology, they would not be able to succeed unless they greatly improve their electrical knowledge. Even a master electrician doesn’t really need to know all that much. They are mainly trained how to assemble electrical systems. They don’t need to know a whole lot about how they work.
Electricians, of all types, and the other construction trades are known for using a lot of slang terminology and referring to items by brand names. The difference is that they are communicating informally among themselves. That’s different from what we do. We are supposed to be professionals. We memorialize our findings in written reports. As professionals we should know and use proper terminology.
As an electrical fire investigator and a forensic electrical consultant, I have been deposed many times and I have assisted lawyers with preparing arguments for depositions, arbitration, and trials. It is very easy to back most electricians, including the company license holder (or holders), into a corner and get them to buckle solely on terminology. I guarantee you that if a home inspector were being deposed and said that the ground and neutrals are isolated, at any point in the system, the lawyer would tear him up.
InterNACHI has been publishing a lot of stuff lately with lots of errors. This video is disgraceful. I started making a list of errors, but I gave up half an hour into it. I jumped ahead to a few places and continued to find errors. Obviously, no one at InterNACHI is concerned with quality and accuracy.
I also listened to a couple of InterNACHI’s podcasts. There are basic errors in every one that I listened to. It wasn’t long ago that Ben posted an article that was full of errors, including referring to multiple phases in a single-phase system. I mentioned that error in this forum. Whether the article was updated, I don’t know. One of the podcasts that I listened to again referred to the two 120V lines being opposite phases! They are not opposite phases because there is only one phase. That’s why it’s called a Single-Phase system! Single means ONE. There is no other phase to be opposite of. Why is that InterNACHI cannot get right something that is so basic?
In another podcast, there is a mention of Exterior Flexible Conduit, type UF, which is not suitable for direct burial! There is NO SUCH THING! UF Cable is a style of non-metallic sheathed cable intended for direct burial. UF stands for Underground Feeder. There is no flexible conduit designated as Type UF.
I don’t know what’s going on at InterNACHI, but this is embarrassing. It seems that there’s no concern about quality or accuracy. To perpetuate misinformation such as saying that there is more than one phase in. single-phase system, that the two legs of a single-phase system are on opposite phases, that there are floating neutrals, that the grounded and grounding conductors are isolated from each other, and other basic errors is inexcusable.
I posted this video in another discussion about what Isolated means in the electrical world. The narrator is a well known, highly respected electrical trainer.
I agree with you on that. If you take a length of #14 and a length of #10, that are each 10’ long and measure the resistance, the difference is small enough (14 AWG 0.02525 Ω, 10 AWG 0.01018 Ω) that, while it is a factor, it is only one of many design factors, and it is certainly an oversimplification.
If you apply a load, there will be a very small difference in voltage drop across our 10’ lengths of copper because of the small difference in resistance. The greater the load, the greater the Voltage drop. Of course there will be more Voltage drop over a greater distance because of resistance, but that is NOT why we put a #14 on a 15A breaker or a #10 on a 30A breaker. The reason is the ability to withstand and dissipate heat, not only of the copper conductors but all the associated components. Obviously, there is a correlation between resistance and thermal energy, but heat is main reason for design differences.
If it were resistance alone, as the video says, why would conductors with different insulation have different ratings? Basing the gauge and overcurrent protection would mean that PTFE, S-glass braid, and ceramic fiber braid would have exactly the same rating as PVC insulation because the resistance of the copper conductors is exactly the same. Such is not the case however. We also have different ratings for conductors being in free air versus in a conduit. The resistance is essentially the same, but the ratings are very different. Granted, the heat increases the resistance, but the Ampacity is not determined solely by the resistance.
According to the NEC, a #14AWG copper conductor with TW insulation has a temperature rating of 60°C while that same copper conductor with mineral insulation (type MI) is 250°C. However, the NEC limits the maximum overcurrent protection and 250°C exceeds the thermal limit of the copper conductor. The NEC, and sound engineering principles, take into account those and other factors also.
A #14 bare copper conductor in free air can easily carry 40-45 Amperes at 30°C ambient temperature, three times what the NEC generally allows. If resistance were the determining factor, the limit on #14 copper would be 45A, not 15A. So while resistance is a factor in design capacity, it is only one factor; it is not “The reason” for limiting a particular gauge to a particular overcurrent rating.
I read what you wrote. Did you watch Ryan’s video or read what I wrote? Did you read the ChatGPT conversation?
You said that the grounds and grounding conductors are isolated at the sub-panel. They are not. They are separated and insulated within a sub-panel, but they are not isolated from each other. Their connection together isn’t visible in the sub-panel and it isn’t supposed to be because they are separated. That doesn’t make them isolated. If they were isolated, there would be no electrical continuity between them. There is continuity because they are not isolated. There is a continuous conductive path. Being separated within a particular space and being isolated are two very different things.
Grounded conductors and grounding conductors are isolated in relatively rare instances. One of the places where they are isolated is in hospital operating rooms as Ryan discusses in his video. I have never worked in hospitals but I have worked with systems where the grounded and grounding conductors are isolated from each other, such as a natural gas compression houses in waste water treatment plants. They are never isolated from each other in a residential electrical system in a sub-panel or anywhere else.
Reasonably competent electricians, electrical engineers, and inspectors should know and understand the difference between merely being separated at a particular location and being isolated. It is a very simple concept. If there is electrical continuity between them, they are not isolated from each other.
It doesn’t matter where in a residential building you check them, there should be electrical continuity 100% of the time, at every location. There’s no such thing as being isolated at one location but being connected together at another; that is, unless there is a problem with the electrical system that needs to be corrected.
Home inspectors and electricians can’t go around making up their own definitions of long established electrical engineering concepts. It is the personal choice of every individual inspector how professional, or unprofessional, he wants to be, Knowingly misusing common electrical terminology is unprofessional in my opinion.
That’s a good video. But George, it doesn’t have anything to do with the way you are trying to define “isolated.”
He is referring to an “Isolated Power System” which includes an isolation transformer. BTW, I was unfamiliar with this so the video was fascinating and thanks for referring it. The isolation power system could have been named “Independent Power System” or “Separated” or maybe “Stand-a-lone”. And it is not technically isolated, because it does not have a separate or isolated power generator. Power has to be brought to the transformer from the same grid used by the rest of us to power the isolated power system so it is “connected.”
“Isolated” does not have a special or altered definition in the electrical world.
Under NEC Article 100, “isolated” is “as applied to location.”
We may end up agreeing to disagree, but… I am correct about this. The dictionary definition of isolate doesn’t mean something is never separated from other things throughout time or space. Things can be isolated at a specific time and in a specific space. It is not contradictory to say that the neutral and grounds are isolated from each other in the subpanel but connected in the service entrance. I confess, that I have never described it that way, but that doesn’t make it wrong. Regarding the word “isolate”, since I like analogies, including the bad analogies, a prisoner is sometimes isolated for a while in time and space, but joined later with the main population. Sick people may be isolated in a separate area of the hospital, and later placed in a shared room when they are no longer contagious.
This is clearly a stump issue for you. I have some stump issues also, but I strongly suggest to you that on this one, you are being unjustifiably hyper critical and choosing to fight on a molehill that most of us don’t see or share your criticism. (This can’t be a fight to the death because I doubt that any of the rest of us think it is worth it. I am unlikely to comment further)
I rarely bother with ChatGBT because I find it only marginally useful and the time I spend verifying information from it takes about the same amount of time I use to do my own research. I like to call AI “Artificial Ignorance”.
“Isolate” and “inaccessible” are not synonymous, if that is what you are trying to imply. To “isolate” means to set apart, while “inaccessible” means unable to be reached.
Yes, “isolate” and “separate” are synonymous, as “isolate” means to place or keep apart from others, while “separate” can mean to move or set apart.
However, “isolate” often implies a more complete or intentional separation, sometimes with the goal of keeping something in a contained state or distinct from contact and influence.
Think of a shut off valve on a water heater. It’s meant to isolate the water heater for servicing. It doesn’t separate the water heater. The same with a gas valve which isolates an appliance. A circuit breaker isolates the circuit.
Grounds and neutrals are separated in a sub panel not isolated.
Correct. For example with something like the old isolated ground systems from the 90’s the system and the isolated ground conductor is still grounded. The EGC is not just floating around in space. It is mechanically and therefore electrically isolated at every point in the system but one.
The IG is connected only at the point where the system bonding jumper is installed at a transformer or where the main bonding jumper is installed at the service. The EGC is completely isolated from everything else. Nothing wrong with the term isolated when used in the correct context.
I am correct about this. The dictionary definition of isolate doesn’t mean something is never separated from other things throughout time or space. Things can be isolated at a specific time and in a specific space. It is not contradictory to say that the neutral and grounds are isolated from each other in the subpanel but connected in the service entrance. I confess, that I have never described it that way, but that doesn’t make it wrong. Regarding the word “isolate”, since I like analogies, including the bad analogies, a prisoner is sometimes isolated for a while in time and space, but joined later with the main population. Sick people may be isolated in a separate area of the hospital, and later placed in a shared room when they are no longer contagious.