Solar

[LopezBart]

Unfortunately I am starting to lose faith in our ability in the USA to do much of anything without excess complication. Solar needs to be better addressed so it does not end up discouraged.

There are lots of folks out there convinced they know exactly how to hook things up, and who are you to tell them anything different. Lots of folks in my demographic, unfortunately. The domain doesn't seem to matter - electricity, hydraulics, steam, ...

Too many folks say "get 'er done" instead of "get 'er done right".

Lots of people are not accustomed to panels with two sources of power in the same panel - hence the requirement for various warning labels, etc.

Lineman are subject to the stupidity of anyone with a generator; all it takes is one idiot out there.

 

[lund]

There are lots of folks out there convinced they know exactly how to hook things up, and who are you to tell them anything different. Lots of folks in my demographic, unfortunately. The domain doesn't seem to matter - electricity, hydraulics, steam, ...

Too many folks say "get 'er done" instead of "get 'er done right".

Lots of people are not accustomed to panels with two sources of power in the same panel - hence the requirement for various warning labels, etc.

Lineman are subject to the stupidity of anyone with a generator; all it takes is one idiot out there.

Partially agree. Linemen are generally working on stuff energized with way more power than any portable generator can put out.

There is certainly a lot of shoddy work and the regulations are mostly setup for people paying and to protect people paying from substandard contractor work. But they can get crazy over generalized. In a non-rural area it may be near impossible to develop any trust with the local inspection team as a DYI guy and there may be a significant prejudice in the system against DIY.

Case in point. I have a hillside home in Cali. I tend to overbuild stuff and take my time to do things right. Plus I have an R&D Engineering/Physics background and have been working on things from A-Z since a young kid. At first, I started to file for permits in my large home rebuilding project. Then I found that pretty much everything required separate mechanical, electrical, and plumbing permits with multiple stage inspections, high fees, difficult to meet schedule needs, etc. Then talking with an inspector (who did not seem very knowledgeable on much we were discussing on earthquake retrofits and materials choices), they would not allow me to present simple analysis and designs and (due to the hillside home) required most everything to be certified by a licensed professional engineer at EXTREMELY high rates that I could no way afford. So it became worse and worse. This was all depressing. After that, I looked up the permit history for the house (worked on a lot from the early 1970s) and found there was *not one single permit* filed on the house over 40 years from being built from 1968 though 2008 when I started. This was through many pro contractor and handyman jobs both large and small. Some jobs were well done. But some jobs were done by complete hacks that could have never passed a legit inspection at any phase (including a bunch of unsafe electrical mods not to code). But none of them had permit records in spite of the many requirements.

You can guess what I did from there. I just kept the layout of the house the same and heavily rebuilt with no permits while doing things to better than code in all cases. I do not anticipate issues if I sell given the past history. But I do live in fear of being vindictively reported by one nutty neighbor (the type of person that causes one to question how one can draw such wrath for no sound reasons!).

 

[ericm]

Line crews would pound on my door at 3 am asking if I was back feeding. They just hear a generator and go nutso.

Weird.

Maybe because I'm in a different part of CA but that's never happened in 27 years of living in this house, in a place with a lot of outages. I've had many conversations with linemen and none have said a word about the generator.

 

[pembol]

Partially agree. Linemen are generally working on stuff energized with way more power than any portable generator can put out.

Some lineman do live line work in controlled situations - but a repair crew (or neighbor) trying to get that branch off the line or get around the downed line is not one of those situations. A portable generator produces more than enough 'power' to kill someone. Anti-islanding is a really serious thing, as opposed to most electrical work, you have the ability to cause harm off your property. Unfortunately there are lots of examples of lineman being injured or killed in these situations.

That said, in most jurisdictions you can do your own solar work, but it needs to be permitted and inspected regardless of who is doing the work, in addition to any requirements from the PoCo.

 

[pembol]

There are lots of folks out there convinced they know exactly how to hook things up, and who are you to tell them anything different. Lots of folks in my demographic, unfortunately. The domain doesn't seem to matter - electricity, hydraulics, steam, ...

Too many folks say "get 'er done" instead of "get 'er done right".

Lots of people are not accustomed to panels with two sources of power in the same panel - hence the requirement for various warning labels, etc.

Lineman are subject to the stupidity of anyone with a generator; all it takes is one idiot out there.

I also think I am also in a demographic that is apt to make this sort of mistake - I have degrees in EE and physics and have a tendency to suffer from what we call 'physicist syndrome', which is the idea that you can figure anything out from first principles, and don't really need practical experience or training.

Generally I can figure out how things are supposed to work, but don't have the practical experience to know and plan for all the ways that it could, and at some point will, go wrong. Which is where the electrical codes and inspectors come into play, they are based on decades of experience of things going wrong, and take the wild card of human nature into account - I don't always know why the code is the way it is, but it is usually for a good reason that I haven't thought of.

 

[wyliesdiesels]

Line crews would pound on my door at 3 am asking if I was back feeding. They just hear a generator and go nutso. Several looked legitimately concerned yelling about it even (I guess company propaganda got some of them too). I put a sign on the door saying "No generator backfeed." It did not help. After a few rounds of early morning wake ups, I gave up and decided to do without.

which power co? what part of cali are you in?

 

[lund]

Some lineman do live line work in controlled situations - but a repair crew (or neighbor) trying to get that branch off the line or get around the downed line is not one of those situations. A portable generator produces more than enough 'power' to kill someone. Anti-islanding is a really serious thing, as opposed to most electrical work, you have the ability to cause harm off your property. Unfortunately there are lots of examples of lineman being injured or killed in these situations.

That said, in most jurisdictions you can do your own solar work, but it needs to be permitted and inspected regardless of who is doing the work, in addition to any requirements from the PoCo.

Thanks for the correction. I would have naively thought linemen are used to doing much live line work.

But a comment. I was working on a lot of electrical equipment when I was a student (as a tech) with open chassis trouble shooting. I got light shocks from time to time. But it is pretty hard to kill yourself on 120 V rms, 60 Hz AC if you work with reasonable prudence. 240 V (line to line, phase) one should be a bit more careful. Any work on electrical stuff you should think about where you stand, what you grab, etc and avoid making yourself a through body conduction path ... whether you think the circuit is safe or not. I am very surprised if trained linemen do not work that way. Grated, things can go wrong and a lot of dumb stuff gets done with big numbers all over the country. If one is worried about positioning, it can be prudent to ground the input of the circuit being worked on to effectively bypass yourself if Murphy's Law hits. Large capacitors and battery packs really scare me. Those can be quite dangerous and need more substantial care. I would be nervous if large battery packs end up all over and get tinkered with by people who do not know that they are doing.

 

[lund]

which power co? what part of cali are you in?

It was Pacific Gas and Electric (PG&E) around 2013 in the Oakland Hills when this was happening to me. After early morning 3 rounds I had enough of it and just avoided use other than brief day intervals to run the fridge and empty the sewer pump basin.

PG&E had a lot of issues after that time and I think became even more extreme. California has a lot of unusual problems though. I was more surprised that the crew seemed to not understand that the (very small portable in my case) generator was being run completely out of circuit. Maybe they saw a cable going into a box and did not see my house on a registry of some sort (does that exist?) so they assumed I could be back feeding the panel? It struck me as a little odd that I had to repeat what I was doing several times each time I was roused (different guys, I think, each time) and they seemed stressed over what I would have thought was a common thing.

 

[pembol]

Thanks for the correction. I would have naively thought linemen are used to doing much live line work.

But a comment. I was working on a lot of electrical equipment when I was a student (as a tech) with open chassis trouble shooting. I got light shocks from time to time. But it is pretty hard to kill yourself on 120 V rms, 60 Hz AC if you work with reasonable prudence. 240 V (line to line, phase) one should be a bit more careful. Any work on electrical stuff you should think about where you stand, what you grab, etc and avoid making yourself a through body conduction path ... whether you think the circuit is safe or not. I am very surprised if trained linemen do not work that way. Grated, things can go wrong and a lot of dumb stuff gets done with big numbers all over the country. If one is worried about positioning, it can be prudent to ground the input of the circuit being worked on to effectively bypass yourself if Murphy's Law hits. Large capacitors and battery packs really scare me. Those can be quite dangerous and need more substantial care. I would be nervous if large battery packs end up all over and get tinkered with by people who do not know that they are doing.

This is kind of the issue with a little bit of knowledge being dangerous. That 120/240V from your generator or solar backfeeds the transformer on the pole/pedestal outside your house, where instead of being stepped down like in normal operation, it is now stepped up to the transmission line voltage (4 - 7kV) which is plenty to kill someone, or cause arcing and a fire. There typically aren't reclosers between every house to protect in this sort of sitaution.

I am sure the protocol for all line work is to assume the line is hot, but with a damaged grid and unknown sources, that is way harder to do in practice. You can also check that it is not hot, then some knuckle head fires up his generator plugged into the dryer outlet, after you measured.... Secondly, it is not just linemen who come in contact with damaged lines, think first responders, neighbors etc.

 

[lund]

I also think I am also in a demographic that is apt to make this sort of mistake - I have degrees in EE and physics and have a tendency to suffer from what we call 'physicist syndrome', which is the idea that you can figure anything out from first principles, and don't really need practical experience or training.

Generally I can figure out how things are supposed to work, but don't have the practical experience to know and plan for all the ways that it could, and at some point will, go wrong. Which is where the electrical codes and inspectors come into play, they are based on decades of experience of things going wrong, and take the wild card of human nature into account - I don't always know why the code is the way it is, but it is usually for a good reason that I haven't thought of.

We may have a similar background. I am a PhD R&D physicist/professor that switched from EE. In my case though I was working from a young age rebuilding homes, mechanical, electrical, plumbing, etc. So I have handy skills too and appreciate craftsmanship. Professionally, I teach mostly postgrads in the universities covering topics like RF cavities and superconducting magnets. Plus I was an electrical/electronics tech to earn $ in my younger days to put myself through school. Generally speaking, home wiring is not very complicated: just 2 phase AC in steady state. I follow the most updated electrical codes when I work and look up info as needed. But most of the home stuff is relatively obvious outside of maybe things like polyphase motor controllers. Some of the solar stuff with phase controlled inverters synching to line with battery banks etc are probably getting a bit complex (and perhaps dangerous if botched) also. But the stuff we have at work with cryogentic temps, exotic materials, high frequency EM waves, etc is otherworldly on the complexity scale. Perhaps that has left me delusional

 

[wyliesdiesels]

It was Pacific Gas and Electric (PG&E) around 2013 in the Oakland Hills when this was happening to me. After early morning 3 rounds I had enough of it and just avoided use other than brief day intervals to run the fridge and empty the sewer pump basin.

PG&E had a lot of issues after that time and I think became even more extreme. California has a lot of unusual problems though. I was more surprised that the crew seemed to not understand that the (very small portable in my case) generator was being run completely out of circuit. Maybe they saw a cable going into a box and did not see my house on a registry of some sort (does that exist?) so they assumed I could be back feeding the panel? It struck me as a little odd that I had to repeat what I was doing several times each time I was roused (different guys, I think, each time) and they seemed stressed over what I would have thought was a common thing.

no such registry.

i wouldve installed an interlock. that wouldve eased their fears

 

[lund]

This is kind of the issue with a little bit of knowledge being dangerous. That 120/240V from your generator or solar backfeeds the transformer on the pole/pedestal outside your house, where instead of being stepped down like in normal operation, it is now stepped up to the transmission line voltage (4 - 7kV) which is plenty to kill someone, or cause arcing and a fire. There typically aren't reclosers between every house to protect in this sort of sitaution.

I am sure the protocol for all line work is to assume the line is hot, but with a damaged grid and unknown sources, that is way harder to do in practice. You can also check that it is not hot, then some knuckle head fires up his generator plugged into the dryer outlet, after you measured.... Secondly, it is not just linemen who come in contact with damaged lines, think first responders, neighbors etc.

The generator I was mentioning was a small portable with a ~1.5 KW. It was only 120V also (not sure they would recognize that from sight). But I seriously doubt any small generator would not be pulled down by local loads all the way through a step up transformer. Sure, you can cook up something hypothetical with everything open in the secondary and the primary pulled down ... but I think the line crews are more realistically worried on a dangling wire being unexpectedly driven or me possibly zapping the neighbors (with them liable?) as you point out. I would add that crews should *always* work on things like they are live unless they are purposefully clamped to ground with some form of lockout. Elect tech troubleshooting for lab instrument was the worst case for me since you would have to energize the system to find problems while poking around (which would often require some degree of safety bypasses). I quickly learned on that job (!) to do most everything one handed and think what and how I was contacting things before doing so.

 

[LopezBart]

Generally speaking, home wiring is not very complicated: just 2 phase AC in steady state. I follow the most updated electrical codes when I work and look up info as needed. But most of the home stuff is relatively obvious outside of maybe things like polyphase motor controllers.

I remember trying to explain to friends why the electrician who had wired their RV bus had made a mistake by bonding the neutral line to ground, and why that was causing the GFCI in their spider box (this is a camp at Burning Man) to trip when the AC went on.

Some of this stuff isn't obvious to folks. Like back-feeding transformers.

 

[lund]

no such registry.

i wouldve installed an interlock. that wouldve eased their fears

Thanks. You a lineman? The more I think about it, I can understand the worries with unknown people doing odd stuff while working on high power systems. The high voltage parts of the transmission system are certainly dangerous and would scare me to death to work on! I say this coming from a physics lab background (large charged particle accelerators) also. I don't think the heights would bother me (used to mountain and ice climb), but wet/damp and dirty outside around high voltage is enough to make me sweat (oh ****, that makes you more conductive too ...).

 

[pembol]

The generator I was mentioning was a small portable with a ~1.5 KW. It was only 120V also (not sure they would recognize that from sight). But I seriously doubt any small generator would not be pulled down by local loads all the way through a step up transformer. Sure, you can cook up something hypothetical with everything open in the secondary and the primary pulled down ... but I think the line crews are more realistically worried on a dangling wire being unexpectedly driven or me possibly zapping the neighbors (with them liable?) as you point out. I would add that crews should *always* work on things like they are live unless they are purposefully clamped to ground with some form of lockout. Elect tech troubleshooting for lab instrument was the worst case for me since you would have to energize the system to find problems while poking around (which would often require some degree of safety bypasses). I quickly learned on that job (!) to do most everything one handed and think what and how I was contacting things before doing so.

Not to be rude, and speaking as a fellow PhD physicist, you are kind of proving the point about physicist syndrome....

 

[lund]

I remember trying to explain to friends why the electrician who had wired their RV bus had made a mistake by bonding the neutral line to ground, and why that was causing the GFCI in their spider box (this is a camp at Burning Man) to trip when the AC went on.

Some of this stuff isn't obvious to folks. Like back-feeding transformers.

Granted.

It is also amazing how messed up some home electrical work can be if nothing more due to sloppiness and poor workmanship. Even stuff like aged electrical sockets with "back stabbed" connections can cause a surprising degree of problems (that min of install time saved was really worth it?). The more modern NEC electrical codes are quite good when properly followed. But neat work and workmanship and conservative standards still counts for a lot. I am amazed what I see when helping friends with older homes. Although I tend to hate buracracies ... I can certainly see the need for estabilished standards and standardization with so many structures and things that can go wrong.

 

[lund]

Not to be rude, and speaking as a fellow PhD physicist, you are kind of proving the point about physicist syndrome....

Umm ... I told you I have practical skills (fully reconstructed 3 homes in my life) also and was an electrical tech etc. So why do you assume I am doing things wrong because I have a also Phd in Physics? I think you should judge individuals as such. We all have different situations. I do things fairly carefully and take time. I also ask experts and look up info.

In intended good humor here: If you want to get more upset in extrapolation ... I am also a theorist in the day job. But believe it or not, I was raised by a family of New England craftsman (who were not so thrilled at first with my career choice years ago ... I literally got semi-insulted with extrapolations that I would lose all common sense and skills).

 

[pembol]

Umm ... I told you I have practical skills (fully reconstructed 3 homes in my life) also and was an electrical tech etc. So why do you assume I am doing things wrong because I have a also Phd in Physics? I think you should judge individuals as such. We all have different situations. I do things farily carefully and take time. I also ask experts and look up info.

In intended good humor here: If you want to get more upset in extrapolation ... I am also a theorist in the day job. But believe it or not, I was raised by a family of New England craftsman (who were not so thrilled at first with my career choice years ago ... I literally got semi-insulted with extrapolations that I would lose all common sense and skills).

Apologies, I am not in anyway doubting your experience and practicality.

I am speaking about theorizing that the lineman (and code inspectors) really shouldn't be so concerned about back feeding the grid as it is a low risk that they would be injured/killed. Neither of us are lineman or grid engineers, and are not taking the risk of working on these lines or fully understand what those risks may be, so I think it is reasonable to default to the experts with training and experience in the matter, and not what we estimate the risk to be.

 

[TheClaw]

I also think I am also in a demographic that is apt to make this sort of mistake - I have degrees in EE and physics and have a tendency to suffer from what we call 'physicist syndrome', which is the idea that you can figure anything out from first principles, and don't really need practical experience or training.

Generally I can figure out how things are supposed to work, but don't have the practical experience to know and plan for all the ways that it could, and at some point will, go wrong. Which is where the electrical codes and inspectors come into play, they are based on decades of experience of things going wrong, and take the wild card of human nature into account - I don't always know why the code is the way it is, but it is usually for a good reason that I haven't thought of.

I'm the same way except my degree is in Aerospace Engineering. I like to say "F=Ma and some calculus I can figure out anything".

However, I stay away from electricity. Ask me why! lol

 

[Innovate1]

The generator I was mentioning was a small portable with a ~1.5 KW. It was only 120V also (not sure they would recognize that from sight). But I seriously doubt any small generator would not be pulled down by local loads all the way through a step up transformer. Sure, you can cook up something hypothetical with everything open in the secondary and the primary pulled down ... but I think the line crews are more realistically worried on a dangling wire being unexpectedly driven or me possibly zapping the neighbors (with them liable?) as you point out. I would add that crews should *always* work on things like they are live unless they are purposefully clamped to ground with some form of lockout. Elect tech troubleshooting for lab instrument was the worst case for me since you would have to energize the system to find problems while poking around (which would often require some degree of safety bypasses). I quickly learned on that job (!) to do most everything one handed and think what and how I was contacting things before doing so.

You really don't want to mess with 1.5kW when stepped up in voltage - it's plenty to kill. IF the grid has several homes on it you probably won't be able to power it up and it will overload the generator. But you never know where the circuits are open or laying on the ground and have to consider the worst case when dealing with safety.

 

[walrus]

During a power outage in Maine if the linemen went up to every house with a Gennie going they would never get anything done. I'm in a rural area and all you can hear is gennies running. If you are back feeding grid here and lineman catch it, your service will be cut and you will be last to get it hooked back up.

 

[Innovate1]

During a power outage in Maine if the linemen went up to every house with a Gennie going they would never get anything done. I'm in a rural area and all you can hear is gennies running. If you are back feeding grid here and lineman catch it, your service will be cut and you will be last to get it hooked back up.

Yeah. I have a hard time believing the linemen are going to hassle someone over a generator running unless they find some voltage on the line or other reason to believe they aren't properly isolated.

 

[reader2580]

I doubt a single utility doesn't require attaching grounds to "dead" lines before the lineman can touch the the lines. It is supposed to be for cases where there is still voltage on the line, like a generator back feeding.

 

[wyliesdiesels]

Thanks. You a lineman? The more I think about it, I can understand the worries with unknown people doing odd stuff while working on high power systems. The high voltage parts of the transmission system are certainly dangerous and would scare me to death to work on! I say this coming from a physics lab background (large charged particle accelerators) also. I don't think the heights would bother me (used to mountain and ice climb), but wet/damp and dirty outside around high voltage is enough to make me sweat (oh ****, that makes you more conductive too ...).

no im an electrician but know several lineman

 

[wyliesdiesels]

I doubt a single utility doesn't require attaching grounds to "dead" lines before the lineman can touch the the lines. It is supposed to be for cases where there is still voltage on the line, like a generator back feeding.

my PoCo sometimes works lines hot... so they cant ground the lines.

 

[reader2580]

Certainly lineman work power lines hot all the time. It is when the power is out that people are going to be running generators. In that case the lines are usually dead, but they generally get grounded before doing any work on the line.

 

[dcg9381]

I remember trying to explain to friends why the electrician who had wired their RV bus had made a mistake by bonding the neutral line to ground, and why that was causing the GFCI in their spider box (this is a camp at Burning Man) to trip when the AC went on.

Shouldn't the ground switching be handled by the transfer switch?

So why do you assume I am doing things wrong because I have a also Phd in Physics? I think you should judge individuals as such. We all have different situations. I do things farily carefully and take time. I also ask experts and look up info.

Don't worry, they do that with EEs too.
And sometimes they are right. I've done it wrong here and there and learned a ton from people on this forum.
Post a photo of your panels, these guys are WAY better than every electrical inspector I've ever met!

I've never failed an electrical inspection, but a 4-year degree, masters, or PhD in a "science" field certainly doesn't qualify anyone to work on electrical. Most of the EE's I graduated with had never used a solder gun.

 

[ToolsRCool]

Snapped a pic of my meter on this cold MI winter morning. I heard the fridge running and furnace blower was on when I grabbed this, and we were still pushing back 2.4kWh into the grid with the sun out bright but at its dismally low winter angle.

On electrical code stuff, I don't know any of it. Best friend is an electrical inspector for the city of Detroit (not the city I'm in), so I just ask him what I need to do. He'll typically tell me 2-3 different ways, one he'd do, then I pick one and do it. City inspector shows up, it passes, and he leaves. No fights, and everybody is happy, legally.

 

[LopezBart]

Shouldn't the ground switching be handled by the transfer switch?

There's no transfer switch on an RV....

The problem w/ tying the neutral and ground together in an RV is that when you plug the RV into a GFCI, both the neutral and the ground share the current... but the GFCI sees less current on the neutral than it sees on the hot line, and immediately trips.

 

[reader2580]

There's no transfer switch on an RV....

Most RVs with a built-in generator will have an automatic transfer switch.

 

[Innovate1]

Shouldn't the ground switching be handled by the transfer switch?


Don't worry, they do that with EEs too.
And sometimes they are right. I've done it wrong here and there and learned a ton from people on this forum.
Post a photo of your panels, these guys are WAY better than every electrical inspector I've ever met!

I've never failed an electrical inspection, but a 4-year degree, masters, or PhD in a "science" field certainly doesn't qualify anyone to work on electrical. Most of the EE's I graduated with had never used a solder gun.

I think that applies to most any certificate or field. I helped a fellow student put together a project and were were both in our 4th year of EE and he asked me what the capacitor in the power supply was. And he was one of the top in his class grades wise. It's a common complaint that college graduates in engineering lack practical experience. I did 6 years in the Navy doing electronics before college and also hobby electronics so I had a lot more background. I have had union carpenters that did really dumb stuff too. It seems like the ones that brag the most about how good they are are usually the crappy ones - not always but over half the time in my experience.

 

[theoldwizard1]

my PoCo sometimes works lines hot... so they cant ground the lines.

That freaked me out the first time I saw it !

The lineman "bypassed" a loose (and SPARKING ) joint. Removed the "connector". Cleaned up the wires. Installed new connector (split bolt?). Tape. Protocol required he wait for a backup person before starting. The backup appeared to be about 20 years longer and he just stood on the ground while the other guy was up the ladder.

 

[theoldwizard1]

The problem w/ tying the neutral and ground together in an RV is that when you plug the RV into a GFCI, both the neutral and the ground share the current... but the GFCI sees less current on the neutral than it sees on the hot line, and immediately trips.

GFCI outlets don't care about ground (you can installed them on old non-ground wiring). They just monitor incoming and outgoing current. If they are different, it trips.

 

[LopezBart]

GFCI outlets don't care about ground (you can installed them on old non-ground wiring). They just monitor incoming and outgoing current. If they are different, it trips.

Right... but you tie the neutral and ground together after the GFCI, any voltage drop in the hot and neutral lines will cause the ground wire to share the current and pop the GFCI.

 

[lund]

Don't worry, they do that with EEs too.
And sometimes they are right. I've done it wrong here and there and learned a ton from people on this forum.
Post a photo of your panels, these guys are WAY better than every electrical inspector I've ever met!

I've never failed an electrical inspection, but a 4-year degree, masters, or PhD in a "science" field certainly doesn't qualify anyone to work on electrical. Most of the EE's I graduated with had never used a solder gun.

Yeah. I realize the trades guys have some annoyance with engineers and designers and that it is not necessarily misplaced at times.

I also agree with you on some of these bulletin boards like garage journal being helpful. I like working on a wide range of nonstandard stuff and they can be GREAT for creative ideas and helpful suggestions. I actively seek advice and read.

My point in the other discussion was more that we are all individuals with our unique backgrounds and experiences. In my case i am now a theoretical physicist, but i have also done a lot trade work from a young age to present including home electrical and electronics technician and designer (including high power stuff). I have soldered thousands of wires, connectors, and pc boards. Yes, it takes touch to do well and the right equipment and materials. I would not say it is so hard as welding (ok ... maybe multi layer pc board repair is) but it can approach an art to do well.

My very limited experience with home inspectors has been pretty poor. I was figuring it must be hit and miss. But the guys i interacted with were not very knowledgeable and did not appear to be very experienced. It soured me on the permit process in cali.

 

[tvand13]

The problem w/ tying the neutral and ground together in an RV is that when you plug the RV into a GFCI, both the neutral and the ground share the current... but the GFCI sees less current on the neutral than it sees on the hot line, and immediately trips.

GFCI outlets don't care about ground (you can installed them on old non-ground wiring). They just monitor incoming and outgoing current. If they are different, it trips.

I'm not sure he could have explained it any clearer, and you still need to argue with it?

 

[dave*99]

I'm not sure he could have explained it any clearer, and you still need to argue with it?

You must be new here....

 

[dcg9381]

I'm not sure he could have explained it any clearer, and you still need to argue with it?

I'm not arguing, but seeking clarification as the "RV space" is having trouble with GFCI on these newer RVs that have large inverter/battery systems.

Is that how they work, looking at a current difference between neutral and hot? They don't actually measure ground current?

In particular, I spent several hours troubleshooting a brand new RV. The one I was working on had a "MasterVolt" inverter and with all breakers shut down it was tripping GFCI. The conclusion that I came too after talking with MasterVolt was that their systems were spec'd for "Marine GFCI" which has an allowable current leak of 30ma. They should not be putting these in RVs as code requires all RV connections to be GFCI now. Residential GFCI is like <10ma.

 

[lund]

Apologies, I am not in anyway doubting your experience and practicality.

I am speaking about theorizing that the lineman (and code inspectors) really shouldn't be so concerned about back feeding the grid as it is a low risk that they would be injured/killed. Neither of us are lineman or grid engineers, and are not taking the risk of working on these lines or fully understand what those risks may be, so I think it is reasonable to default to the experts with training and experience in the matter, and not what we estimate the risk to be.

No problem. We all have our individual traits and backgrounds. I may be a little non-standard with the trade and physics mix. But my main point is it is best not to extrapolate too much.

One of the things I like about Physics as a field is that people are very much from all over with very diverse backgrounds in all directions. You know this, but if others follow and are curious, we have people of all nationalities, groups, ages, etc. When I was a grad student at MIT years ago (early 90s), I think I was the only native born USA guy working in theoretical physics (that low USA count was probably atypical for that specific year, but people being from all over is certainly typical). The laws of nature are definite, so physicists debate -- but typically do so carefully and listen to others for the most part since they do not want to be tagged with making significant mistakes. I have worked in groups with Orthodox Jewish people and Palestinians working together with proper respect. Lunch convos off technical topics could get interesting (!). It shocked me how smart people would have almost opposite interpretations on the same historical events etc! But, to those individuals credit, they managed to productively work together with proper respect.

The reason I come here is to discuss matters of interest to me with tradesmen etc. Many have good ideas and will explain things. I find Garage Journal much better than reddit boards where 75% reply knowing little or nothing and an alarmingly high % to make everything into a joke or insult. There are a lot of good suggestions on approaches to problems and I have learned a lot from reading threads here. Nothing is perfect, but I do not think most scientists refuse to listen and only lecture. Most scientists will admit when they screwed up since nature is specific. Yes, they may be the types to have strong personalities, dive into things, and try a lot. But is that so bad?

The electrician with linesman friends said that most linesmen doing residential hookups do not work on them live. I think many of those neighborhood systems are 13.8 kV line-to-line, (2 phase, rms) in the primary side. I presume they are locking them down for safety so we are mostly talking about energizing to a circuit break (wire fault etc). High power transmission (think usually more than 70kV) is definately scary. I cannot imagine working on it in outdoor atmosphere with dirt/contaminants, water, etc.

You want fun ... try talking with MDs on how they set medicine doses, know things work, etc. Many in that group get defensive quickly. I suspect this occurs since the medical community is trained to project expert authority and to avoid questions to keep a rapid progression of patients necessary for the high salaries and cost. Sure, most of what they are doing is best known practice and they know more. But many in the medical community appear to have a hard time understanding natural curiosity can drive questions. Some want to understand the basis of the approach and want to understand by discussion/questions and are not questioning as a slight of credentials.

 

[lund]

Weird.

Maybe because I'm in a different part of CA but that's never happened in 27 years of living in this house, in a place with a lot of outages. I've had many conversations with linemen and none have said a word about the generator.

I have no good explanation. Maybe it is the specifics of the local crews in the area of the Oakland hills we were in. I certainly did not think it would trigger the issues encountered.