I posted from my saved documents.
I made an official complaint about being stalked.
Saved as you so famously put it.
How are you being stalked on an open message board?
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SAVED!
Did you report yourself for being Racist?
I am part American Indian, born in an Iroquois Hospital in Illinois, USA.
Mr. @mwilles appears to be White American.
He has been giving you a hard time also, and you only report me? WHY is that??
Time for you to get your affairs in order!!
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Or sub-feed lugs.
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Thank you for the additional information.
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They are not isolated. The grounded conductors are always solidly grounded.The neutral would be floating If they were isolated. The neutrals are never isolated from the equipment grounding conductors, the grounding electrode conductor, any made electrodes, or Earth. Neutrals and grounds being isolated is a myth that is disseminated and perpetuated by home inspectors and poorly trained electricians.
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You are splitting hairs again George. All I am saying is that the grounded conductor is only grounded at one point within a home (typically at the main panel or service disconnect) and that it should not be grounded at any subpanel. If you have a better phrase for it than “isolated at the subpanel” please share.
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Separated.
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That may be what you think you are saying, but it isn’t even close to what you are actually saying. What you are saying is that the system’s grounded conductor needs to be removed from its connection to ground at the service and at the transformer to create a floating neutral. I know of no building code or utility company that allows that in a residential electrical system. So, using a term the meaning of which is the exact opposite of what you are saying is far from splitting hairs.
It isn’t anything like referring to a panel as either a sub-panel, distribution panel, or load center. It isn’t anything like referring to a receptacle outlet as either a receptacle or an outlet. You are saying to fundamentally alter the system in such a way that it would violate multiple building codes, would be in conflict with standard utility company design criteria, and would create a system that is less stable than it would be with a solidly grounded neutral conductor. It is a very important and fundamental concept in electrical system design.
Ryan Jackson explains what an isolated ground is in this video. What’s especially interesting, and sad, is that he said he got an email from a confused apprentice who couldn’t get a satisfactory answer about an isolated ground (floating neutral) system from either his foreman or his apprenticeship instructor. That’s the state of the industry today. There are too many poorly trained electricians supervising electrical installations and even electrical instructors who don’t know the basics. I watched half an hour or so of an InterNACHI training video recently. The two instructors both made many egregious errors, among them being saying that the EGC and the neutral should be isolated. That’s inexcusable! One instructor repeatedly referred to conductor “Amplicity”. The video is an embarrassment.
The NEC and any good training or reference manual will say that the grounded and grounding conductors are to be separated on the load side of the service. I prefer to say “Separated”. Sometimes I will say separates and insulated for additional clarity. Insulated would be acceptable. Now, if someone were to argue strongly in favor of one or the other either between separated and insulated, that would be an example of splitting hairs, but to use a term that has the exact opposite meaning from what you mean is not splitting hairs.
Misusing terminology is unprofessional and unacceptable.
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Great video, George. I fully understand now why you’re so passionate about the misuse of the word “isolated”. I enjoyed Ryan’s enthusiasm at 13:12 when he said, “if you ever get to wire one, take the time to…enjoy it”.
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Great isolated ground video by, Ryan Jackson.
Thank you, George.
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I trust ChatGPT and here is its response that clearly presents the argument that “isolated” is the correct adjective:
//
Excellent and very precise question — and yes, in electrical distribution wiring, “isolated” and “separated” have distinct meanings, especially in formal electrical code contexts (like the NEC, IEC, or IEEE). They’re related concepts but describe different physical or functional relationships between conductors, circuits, or systems.
Let’s break it down clearly:
Isolated
Definition (conceptually):
“Isolated” means electrically disconnected from other circuits, systems, or conductive materials, except through intentional connections such as grounding or specific devices.
Purpose:
Isolation is primarily about preventing unwanted current flow or electrical interaction between systems or between a circuit and ground.
Examples:
- An isolated grounding system uses a dedicated equipment grounding conductor that is insulated from the building’s grounding path until it reaches the service ground.
- A transformer with isolated secondary means there is no electrical connection between the primary and secondary windings — only magnetic coupling.
- An isolated receptacle (orange triangle type) has its grounding terminal separated from the metal box to prevent electrical noise from the building grounding system.
Key idea:
Isolation means there is no conductive (galvanic) path between two things.
Separated
Definition (conceptually):
“Separated” means physically or mechanically spaced apart to prevent contact, arcing, or interference — but not necessarily electrically isolated.
Purpose:
Separation ensures physical distance or barriers for safety, thermal protection, or to meet clearance/creepage requirements.
Examples:
- Separated conductors in a panelboard are those physically spaced to avoid arcing between phases.
- A “separated circuit” might share a neutral or raceway with other circuits but has separate conductors and overcurrent protection.
- In control panels, “separated compartments” are used for low-voltage and high-voltage wiring to avoid interference or accidental contact.
Key idea:
Separation means there’s physical distance or insulation between two things, but they might still share a common electrical system.
Summary Comparison
| Term | Focus | Typical Meaning | Example |
|---|---|---|---|
| Isolated | Electrical connection | No electrical continuity or conductive path | Isolated transformer secondary, isolated ground receptacle |
| Separated | Physical or mechanical spacing | Physically apart or insulated to avoid contact or interference | Conductors separated by barrier or air gap in a panel |
| Overlap? | Sometimes both | A system can be both isolated and separated (e.g., transformer isolation with physical spacing) | Medical isolated power system rooms |
Code References (for context)
- NEC Article 517 – “Isolated Power Systems” in healthcare facilities.
- NEC 250.146(D) – “Isolated Ground Receptacles.”
- IEC 60364 – distinguishes between “separated extra-low voltage (SELV)” and “isolated” systems.
- UL 508A – differentiates “electrical isolation” and “mechanical separation” in control panels.
So, in subpanels, should the neutrals be isolated or separated from the ground conductors?
ChatGPT said:
Perfect follow-up — this is a critical distinction that every inspector should understand and be able to explain clearly.
In subpanels, the neutral conductors must be isolated from the equipment grounding conductors (EGCs) — not merely separated. Let’s unpack that carefully:
The Correct Rule (NEC 250.24(A)(5), 250.32(B))
In any panel downstream of the service disconnect, the neutral (grounded conductor) must be isolated from the equipment grounding conductors and the panel enclosure.
What “Isolated” Means Here
- Isolated = no electrical connection between the neutral bus and the *ground bus or metal panel enclosure.
- The neutral bus should be mounted on an insulated base, not directly bonded to the panel body.
- The bonding screw or strap (which ties the neutral bus to the panel enclosure in a main panel) must be removed or left out in a subpanel.
This ensures that:
- Neutral current returns only through the neutral conductor.
- The equipment grounding path carries current only during faults.
- There are no parallel return paths or stray neutral currents on metal parts or grounding conductors.
What “Separated” Would Mean (and Why It’s Not Enough)
- Separated would mean the bars are simply physically apart — for example, located on opposite sides of the panel.
- But if they’re still bonded together (via a strap, bar, or screw), then they’re not electrically isolated, and that’s a code violation and a safety hazard.
So:
You can have the neutral and ground bars separated by space,
…but if a bonding screw connects them, they’re not isolated — and that’s the real problem.
Summary Table
| Panel Type | Neutral–Ground Relationship | Bonding Strap/Screw | Notes |
|---|---|---|---|
| Main Service Panel | Bonded (connected) | Installed | Neutral and ground meet only here |
| Subpanel (downstream) | Isolated (not bonded) | Removed/omitted | Neutral and ground kept separate to prevent parallel paths |
Inspector’s Narrative Example
The neutral bus in subpanels should be electrically isolated from both the equipment grounding bus and the panel enclosure. This prevents neutral current from flowing on grounding paths, which can present shock hazards and interfere with equipment operation. The grounding bus should remain bonded to the panel cabinet and grounding electrode system.
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Sure, ChatGPT can make mistakes. But, it predominantly provides well-written, excellent, information. If you know the subject matter yourself, you can catch any small mistakes. In this case, I was really saying I trust ChatGPT more than George.
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You meant to say “Is not the correct adjective”, right? The responses clearly indicate that isolated is not the correct term to use.
That is an incorrect statement. Ryan’s video shows how a properly wired isolated ground system is wired and why. It is true that some electricians do not use IG receptacles as they are intended to be used, but the fact that someone does something wrong, even if it is a lot of someones, doesn’t make it right.
A properly wired Isolated circuit never goes back to the service ground. It is electrically discontinuous, as ChatGPT later mentioned.
ChatGPT culls information from a variety of sources. Many of which are websites by electricians. I often find bad information on websites by electricians. Garbage in > Garbage out. Ryan is a well known and well respected electrical trainer.
Search through this forum and you will see that this is what I have been trying to explain here for many years, there is NO CONDUCTIVE PATH. That’s what isolated means. You can use a basic continuity tester or VOM to verify that in a residential electrical system THERE IS A CONDUCTIVE PATH between the grounded conductor and the equipment grounding conductor, therefore they are NOT ISOLATED.
That’s an accurate statement, but not germane to this conversation. All transformers are one of two types. They are either isolation transformers or they are auto-transformers. However, the world of transformers can be confusing to those outside the electrical trades because there are transformers that are called “Isolating” transformers that employ various techniques to enhance isolation with filtering. If you check any isolation transformer that is not connected to an energy source, you will see that there is no continuity between the primary and the secondary windings. The windings are magnetically coupled when energized.
The same is true of a grounded conductor terminal strip in a sun-panel. It is isolated until conductors are attached to it. As soon as the first grounded conductor is attached to it, it is no longer isolated.
I am sure that there will be home inspectors who read this discussion and watch Ryan’s video but will continue to misuse the term “Isolated”. But, that’s their problem. It is their right to be wrong. I also know, having trained hundreds of electricians and home inspectors, that there are many who are willing to accept that they have been wrong and want to improve their knowledge and understanding. It is that group that motivates me.
I routinely ask all the popular AI services questions that I know the answers to. When it comes to electricity and electrical systems, I frequently get wrong answers and I challenge the AI. I have used Copilot more often than any of the others; enough so that it will now sometimes respond with introductory statements such as “I know you demand precision so …” and it will yield a better quality answer with its initial response than in the past or compared to other AI.
They all do better on successive iterations. I always challenge the initial response regardless of which AI it is. A challenge can be as simple as “Are you sure?”. Many of my challenges are more technical, such as when I know that their are common misconceptions, such as with the misuse of terms such as “Isolated” or Floating neutral” in relation to electrical panels. I’ll say something like “Reconcile your answer with the fact that I can measure electrical continuity between the conductors” when it says that isolated is an appropriate word to describe the relationship of the conductors. Then, I often get subsequent answers along the lines of “Yes you are correct. I based my answer on the frequency with which the term is applied in discussions”. If you look at the references, Reddit is the most common source for the major AI engines. They also often cite thIs message board with anything related to home inspection and many electrical questions. They also look at electricians’ websites, which are notoriously unreliable.
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I think we are not arguing the technical aspects, just the terminology. In my interpretation (and ChatGPT), the neutrals are “isolated” at the subpanel (using that as the total frame of reference), which is the correct term regarding the subpanel only. We all know and agree that the neutral is bonded at the main panel or disconnect (where the neutrals are no longer isolated). This subject should be closed; the readers can pick who to follow.
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I don’t understand how you can possibly conclude that misusing “Isolated” is acceptable based on ChatGPT when ChatGPT contradicts itself, but leans heavily toward a proper definition of “Isolated”. It clearly says that isolated means “No conductive path”.
But, you do whatever you think is right for your business. It is your right to be wrong. You are more interested in seeking confirmation of your bias than accuracy.
I have done my research and come to the correct conclusion.
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