Solar Photovoltaic (PV) Systems, Scope [690.1]

[Music] all right part one general and as we finish apart guys I'd like us to do a summary and Ryan if you can remind if we do a summary and let's correct any mistakes we made or give final comments and before we go to the next part so help me in case I forget first thing is article 690 that one every article has a scope and alerts what's the scope of article 690 and this is an important thing that we want to talk about 690 at 1 the code says article 6 and it applies to solar photovoltaic systems other than those covered by article 691 and this is an important point what is a solar voltaic system well put some graphics we have this in our book and let's just talk about a soul of the take system is there a definition somewhere guys about a soul of a tech system and where's that definition located and Bryan can you go there and let's take a look at it we'll pop it up and we'll actually read it we're gonna call it a PV system Oh article 692 is solar we'll take solar photovoltaic solar photovoltaic co2 okay so we're gonna call it a PV system I'm not gonna find it under s 10 know we had that acronym put all throughout the code P Z because it's too hard to say and most people save photo Bowl Act ik and that sounds like Profoto Blackie you'd be like yeah it's not right ok that's not good ok so now we're gonna go to the code Bryan whenever you get a chance to pop up PV system and let's see if there's a definition of a PV system while he's doing that let's go ahead and take a look at a PV system one of these I try to do on these graphics is to highlight in yellow everything that is considered part of the PV system I want to try to use PV and first thing we do is we want to start with a power source and that is that we're generating energy and this is not a book talking about well how do you generate energy from cells them you know semiconductors we're not going to get into that but just that the Sun hits something and it does something and it causes electrons to move in a given direction and if you get more of these things and the more you put together you'll see later on well then them the more you gotta generate there so we have a power source and guys help me is the word power source an important term in general just the term power source when we get to 705 then we have power sources so we have to recognize that most electricians are dealing with just simply going to load well now we're dealing with power sources and you might have what let's talk about in general concept what a power source is wind solar generator generator generator transformers kind of no I'm just saying it's a Transformers transformer it's transforming it rather and being the source itself so later on we get to 705 is long what happens if you start mixing power sources together what do you put PV in a house and you have utility well we're now having two power sources and we're gonna have to consider that so 690 is only talking about solar voltaic and the other power source a win is 694 706 in energy storage systems okay so we get power sources let's stay on the PV power source alright here's the power source now the wires that lead the power source are called source circuit it's a source circuit follow that now rather than a load circuit you got to work with me here this is really important and just listen to it this is an introduction it's a source and it's a source circuit rather than what Bill rather than a load circuit rather than a load circuit okay so it's on a go it's a power circuit now they have these boxes that they can put these little electronic things we'll talk about DC to DC converters we're not gonna talk about what they do but in a brief just short bill what are why do we have a DC DC converter the shortest because we'll talk about later on what's what does Dave what do they do we don't always have them they just they can be okay in the circuit and they would just there like an AC transformer that's the DC similar device as an AC transformer it does something with the source circuit conductor energy coming in and then it goes out and there's some kind of electronic device here right doing something that we'll talk about later on now we don't have to have DC DC convertors but if you did put a DC DC converter then the conductors that leave the converter okay these are DC to DC converters source circuits these this is the source then you bring them together and you have a bunch of circuits that you combine together and then you're gonna have a combiner and we're going to show some pictures that combine it so now you have three four or five or six number of circuits coming together but I don't want to be running all these wires all the way back there I can kind of put them in a box and then combine them together and then instead of me running six circuits of two wires in back to the source I mean back to the inverter I can put those six circuits into this combiner and then just run two conductors but of course the two conductors are going to be bigger because it's going to be the combination of the power sources added together but it's a lot easier to run a little bigger wire and a bigger pipe but there's only two wires as opposed to having six circuits going back so it's just a convenient way of getting it back over to the source so that's gonna be then a combiner well then the conductors leaving the combiner or it's the combiner output because the electrons are going the other way they're not going to the power source they're leaving the power source once a source that's the output so as you're kind of gaining closer utility this is the output and now so in and the combiner is usually a disconnect is that good common thing guys the combiners have disconnects on okay well it's a disconnected whatever and then it can output circuit that's going over it now to an inverter now the inverter if you notice the symbol here is converting DC which is symbol shown here to the sine wave which is AC so it's an interactive inverter which means that I have a disconnect because electrons are leaving the power source going through the DC convertors and then they have sorcerer conductors combined or combiner output circuit conductors going to a disconnect now going to the inverter because I want to be able to disconnect power the DC power that's coming into the inverter so now we're having an equipment disconnect this is the inverter DC disconnect okay so we have to have a disconnect so you can then work on that inverter to turn off the power to work on that inverter so let's take a look at this graphic again so now we have a the inverter DC disconnect here's the inverter and if you notice the arrows here another kind of hard to see on the screen here but the arrow is going this way a single arrow right here that means going that direction into DC and we use pink to kind of show DC and use red lines to kind of represent DC now we're inverting it to alternating current and we're using blue to represent this is the alternate current coming from that power source in other words there's two power sources if you look at the utility the wiring on the utility coming in here is going to be black but the wire coming from the inverter is going to be blue which represents alternating current this is an inverter this is going to be an inverter output circuit oh here it is here's the inverter DC input circuit so the direct current coming into inverter is called the inverter DC input circuit what's leaving the inverter is gonna be the inverter AC output circuit now this is the terms are kind of intuitive you just got to know that it's the DC input the AC output you know but inverter so work with you here then I have a disconnect now this disconnect is the inverted disconnect because if I have an inverter and I want to work on the inverter but I have AC power coming in well I gotta be able to turn off the DC power DC right input and I got to turn off the AC power so I need an a see this kind of DC tonight this is for the equipment so I can service that equipment now I have to terminate that equipment over to the distribution system this is where I'm going to be inter connecting the two power sources notice that the power source I said for the DC inverted over is blue so that's one power source circuit of blue but the utility power sources and black so now we're going to interconnected and I think bill what I should do is I should point here and I should make a reference here that this is article 705 this point right here this interconnection is 705 the everything in yellow is 690 so when we're talking about yellow but once I make this interconnection Brian will make that note there well then how do you connect that blue circuit with the black circuit where blue representing the power source that's coming in that's one power source with a black well we have to go to 706 to make that interconnect 5-7 705 in connection all right well that takes care of Oh bill talk to me about interactive PV what what is what does that mean it looks like in your picture that it's it's the interconnection of black and blue so we're black and blue black in the black teleplay the black commute ility and the blue from the solar is coming together so article 705 is interconnected power sources and so these power sources have to be able to play nice and so that whole process of playing nice usually as in most things the bigger source or the bigger factor sets the rules and the utility system is the bigger source and so when we play nice we we have to get along with our you know Big Brother and so the interconnection process an interactive system when it says it's interacting with the utility source it's actually running in parallel with the utility source so that the the PV system is interacting with the utility system and so the concern then is what that the PV system if the utility loses power and the PV system could then be back feeding so talk about that interactive and that inverter what is that right so it has to it has to be able to synchronize with the utility source okay so that's an AC waveform so it synchronizes with the AC source and then it also has to sense whether or not that source is there and so in a utility outage the the big concern from the utility side is is to continue to energize their transformers things like that which creates a safety hazard for their line workers and the like and so this interactive system must interact with that system in a way that it does it safely it doesn't without damaging the utility system doesn't without damaging the equipment at the customer's facility and then when there is a power outage if it's going to continue to operate then it has to isolate from the utility system and no longer interact so it would actually move into a mode called Island mode in the 2020 code where we would no longer interact but we could still provide power to local sources and we'll talk about that I had the PV system in my house and if I lose power I don't have any power I mean my solar only works and it's not even giving me any current right well it is supplying some of my loads but if it supplies if I need if I have less load than my you took that my PV system supplying well then it's feeding the utility it's gonna be interacting but once I lose power I lose my the PV still there and the electrons are just they're not yeah and so people think that a solar PV system can be used as that backup no but you could but we'd have to add batteries there are other ways to go about it so what this means is this and that is that it the inverter is designed and it's listed under a standard to say hey listen if the utility loses power we don't want you back feeding utility you automatically shut down so the inverter will only work if the utility gives it power because the inverter needs utility power to sense it so that it can start working so they can start back feeding right I just you know as we're looking at this graphic I just want to mention for some people are going to be a lot more familiar with the different components on graphic and some people are going to be less familiar those are just representative parts and this is just diagrams all of these diagrams are so that we can explain to you how things work together not that this is the only way that things could be done so as you're kind of looking at these things don't think oh my gosh that's where the disconnect happens to be has to be I didn't do my job right or hey that's not what mine looks like because there's a lot of different scenarios and equipments change so much even just in the short time I've been on Bill's been in the industry way longer than I have but just in the short period of time that I've been in the industry the equipment has completely changed what it looks like so it's all diagrammatic look at this right here we have a DC inverter DC disconnect you can buy an inverter that has the DC disconnect incorporated within the inverter or the AC inverter disconnect well you can have an inverted it has the AC and the DC disconnect incorporated with this so now I don't have to have a separate disconnect for the AC to DC or the back fed circuit breaker could be your AC system or we don't even have to have this dis disconnect here because this back to a circuit breaker if it's with it meets the requirements of equipment disconnect yep because that's the PV system that's gonna that's when the system ends so it's a matter of where well where did you locate this how are we gonna follow the code rules but this is saying hey we need a DC this we need to put me this connect like you said our brain we can say okay there needs to be a disconnect there and we all know that a box with a handle on it to disconnect so at least in our brain we can make that connection there all right I'm done with this graphing anybody comments all right let's go to another now we're gonna get little bit more complicated but article six nine let's take a bill to see this is the yellowest 690 right the utility is gonna be general code is that right Jimmy yep sir black is all gonna be whatever the code would be and this interconnection right here of the power production sources is gonna be 705 705 coming over here this is fascinating what 2017 code did was to clarify that the PV system ends at the PV system disconnect so 690 only applies to this very small section if you're going to have a power source and you're going to go to a disk connect and now you're gonna be connecting we're gonna be DC coupling that we have an energy storage system that as a disconnect then maybe the energy source system incorporates a disconnect within the equipment but it still needs a disconnect but that energy storage system is now connected to the DC so let me watch the arrows here electrons are leaving the power source they're coming this way they're going down to the disconnect they're going to charge a battery but there might be times where the battery is going to be powers needed so the electrons can go back to the other direction well they're not going to go up to the power source because they can only go to one direction it's now moving over here and this is the point of DC coupling so should this arrow will be put right to this little point right here I'm sorry is this the point of DC coupling right here the actual point where the DC energy source is making a connection okay think of it think of it as a bus a DC bus yes you're basically supplying power to a DC bus and the inverter is operating off that DC bus that has two sources one is solar and one is energy storage okay so I have electrons going in this direction and II see the arrows they're going this way electrons coming in this way so we could at times have the pv source having current going in that direction and also the battery going in that direction going through the inverter disconnect going through a multimode inverter which is different than an interactive inverter is a multimode inverter and Interactive inverter by its very definition it has two it would include more than one mode that's and one mode is interactive the other mode is standalone is it standalone as an island island mode is the mode that we're yes I think that's that's our word which one I use that's a really good question that's which one should we use for now in this class so I can just not two different ones it's it's we have a standalone article so I think for now you know using the term standalone well I we're standalone I think people understand that great slang has been stand along you know I don't know it is yeah yeah but I know what a stand alone is okay so here we go England so therefore the multimode has interactive mode that means you're interacting with utility or it's gonna be a standalone standalone mode okay I got that I understand that now see soda comes in this direction is going over to the multimode inverter the big graphics we can see better yeah so currently here it goes this direction and it can also charge the battery but it can also then battery to charge here and it goes this direction it goes to multi mode oh if I'm connecting to the utility here then it's gonna go to the blue connecting over here right so therefore I need that to be in the interactive mode but this inverter can also supply supply standalone panel and Brian we need a main breaker on this panel here the panel there needs a man to break with ovarcome protection why well we had to have overcome protection why right panel boys have to have overcome towards out to have a look that's gonna be 408 dot thirty six so panel boards have to have overcome protection from a current limited source yep yeah before oh wait that's that 36 doesn't get into tough and good doesn't say bright apply all sources okay so we'll put an open come protection device it commits a 200 amp panel then I have to have an overcurrent advise not exceeding that but maybe somebody could write something maybe 690 could say hey if you know then you guys can you can because 690 can do what override what 408 not 36 is it make it PvP I I'm not okay so now electrons are going in one direction here to the standalone this thing can supply both of these I got it if I use if I lose utility power and if it's a in the daytime I'd have solar power supplying the multimode inverter in the standby mode right if it was nighttime I could use my batteries and of course you can use them both even a daytime you know one way here's my DC disc and my inverter disconnect DC side my inverter disconnect AC side my PV system okay so now let's talk about code sections so Bryan we want to put energy storage that's article 705 right 606 energy storage system that's an article and Bryan let's shade this including this conductors right here because that includes a disconnecting me so that's article 706 oh then we need to show the standalone what we need to shade this right here Brian and this is gonna be article 710 burnt the DC loads so I guess this is just code yes it's just chapter 2 chapter 2 all chapters you know get the wire size record everything else like that okay and then this is utility which is just code now services in utility distribution they're black see the black sine waves versus the blue now an interesting point I wanted to make here is I'm shorting the ground at the utility and I'm not gonna get into grounding and bonding but I want to go back to the mall to the interactive one just to make a statement all these metal parts and all these pieces are all gonna be tied together they're all going to be bonded together in accordance with chapters one through four specifically article 250 and there's a little bit something in six planning about some bonding and grounding but but basically if you're running raceways or enclosures you're gonna be putting that happens emt and putting the lock down on there and tighten it down and you're gonna be running equipment grounding conductor that's all just general requirements so if you look at this graphic all these metal parts are all connected together and they're all connected together connected to the distribution equipment and everything is all connected together everything is bonded and it is grounded my point is this there's nothing that you do to a PV system at all zero all parts are bonded together and that's it and then you're done we'll get into that once you get into 690 that 45 and 43 and 47 so let's go be here multimode all metal parts everything is all bonded together that's all we have to do make we install it per the code and that it's automatically grounded there's nothing else to do let's go to this okay an AC couple multimode okay I know what multimode means that means that what I can work off interactive or I can work off with the standby mode all right is my power source on one second this was 690 energy storage was 706 stand alone was 710 where does 705 come from here interactive point when you tie into the utility 705 is gonna be so right here is 705 right right so we have to point this point right here that's 705 that's that interact interactive disconnect is gonna be there right here okay got that one so now it's AC coupled to my second DC couples right here cuz I'm taking this source and I'm taking this source I'm DC coupling it all right multimode which means I'm going with interactive and standby okay energy comes this one see the arrow go in one direction go under action this is an interact oh this is an interactive and inverter okay then going out of here and I going to the PV system disconnect that's article 690 it ends right here and this point right here is gonna be article 705 at this point right yeah what do I have here okay I got batteries so they have that energy storage article 706 the disconnect that I'm gonna supply this oat so the battery is gonna supply an in multimode inverter which makes it works interactive and it works standby okay so it goes here so it can go this direct oh oh here's where it's going interactive right which then at this point right here is gonna be 706 also isn't it I bet agree that 705 now getting your numbers backwards I have to stop and think okay how about working on that okay seven okay I'm gonna be connecting here it's 7:05 okay got that so this is going oh so this is say stand by Brian let's make sure this is gonna be stand by and this is gonna be article 710 so we'll put on there and we need a main breaker in this also well we're back feeding it so that's fine there's your breaker okay so that's stand by I want to see some stand along the loan not stand by okay so Bronte out of 702 okay all right so we're gonna could do a 702 so this is going to be standalone AC panel this would be a standalone AC panel so this okay so let me see if I understand why am I doing this okay hold on I got batteries oh now I could use this as a backup power system right where oh the DC coupled could be used any batteries for remote you have that multimode inverter go so if I got this what's a dead machine for this one can I help you yeah help me okay yes difference between these two is just saying how the PV system is coupled to the multimodal system okay okay we can couple that system in a DC manner we can couple it in an AC manner in the AC coupled system we have a DC coupled battery in that example but their focus in 690 was on the ACS I was on the PV system okay so we have a DC coupled PV system and an AC coupled PV system a really important point to get across to electricians that they generally just do not get is that a multi-modal inverter is operating in two dramatically different operating modes okay the interactive mode is what we call a current mode it just produces current it has it does not actually run a single load in your house so it's inaccurate to say that it's running something in my house it's only producing current and to the extent that the total current of your house is less than or equal to the PV system okay then it is essentially running as much energy as the house is consuming at a given moment in time but it is physically incapable of running those loads it's not designed to run them directly it has to run in what we call voltage mode so when it when it runs when it goes to standalone mode it has to turn itself it actually changes operating mode from controlling current to controlling voltage now and that's the way most generators work is they control voltage the generator that you buy that you you know gasoline-powered generator all right that's designed to control voltage to keep it within 240 volts plus or minus 5% or 120 volts depending on what you bought all right and it's holding that voltage constant so that loads can pull the current they need from that voltage source all right now it's really running loads so when you go into standalone mode you are actually running loads off of the system in interactive mode you're not running anything off the system it's just an arithmetic accounting of current flows that's all it is all right what I see now looking at this graphic is if I'm taking the energy storage system and somehow I'm connecting it at this point right here I'm connecting AC here with AC here that is gonna be AC coupled where in the previous one I didn't go through an inverter to get here I've made DC couples so it's just a matter of with AC couple DC couple if you look at this Mike you know it's a source that's a disconnect that's an internal birder you got the disconnect here you're supplying here you got these loads if you come over here it goes this way it goes that way it could supply both ways if you lose power it's gonna get then take the energy storage it's gonna kind of go over here and it's gonna go into voltage mode and it's gonna be supplying your standalone loads Brian yeah just to put this maybe in a little bit more of a practical perspective of just what I've seen and I'm sure Bill can give 10 more examples to this one but this exact scenario you're gonna see where somebody's got an interact system they weren't maybe looking to be able to be standalone when they initially put in the system they were just trying to take advantage of some rebates or whatever the case after the fact they go you know if you're really nice I have this huge array on my roof it'd be really really nice if when the power went out I had power to use and they call up an installer and say hey what can we do so that I don't have to replace all of my equipment and I want but I want to add some storage and then this is where you know you might get a multimode inverter installed and maybe even some more solar or whatever the case might be but well my house I'm in New Mexico and I got an arrays there any there and it's it's an interactive inverter and I'm thinking I want to I want it I want to I don't want to put a generator in case I lose power right because that's I'm thinking putting in a generator so now I I would go to an AC coupled multimode and they said well Mike you need another inverter break why don't have another inverter I already got an inverter do I don't need another very well Mike you need an another inverter because like I don't understand so in my house bill then I would put energy storage system I would had a multi mode inverter right and that's where I'd get my AC couple yep so and again these are as Brian stated these are just simply examples basic examples so there's quite a few other systems out there on the market today and even more coming and in 705 we're gonna get into micro grid interconnect devices and that changes everything okay and so the way you were looking at it here it's helpful for conceptualizing don't get all bent out of shape because there are other systems that are very common now there aren't set up exactly like this what the concepts are still you add an interactive inverters multimode inverters you have energy storage systems you have different articles you have interconnecting of articles so you need to be able to put this together all right let's go on the next one Oh stand alone mode okay stand alone system down oh yeah okay it's not a mode because this is now the articles in this process may be works are put a title here article 710 so alright 710 so 690 okay so 690 ends at the disconnect the PV system disconnect right did we ever get a definition of what a PV system is Brian we did when you get a chance pop that up I'm curious alright so now I have her for you you have it there the total oh I don't see it there okay go ahead read through since I don't have that the total components circuits and equipment up to and including the PV system disconnecting means that in combination convert solar energy into electric energy okay so the PV system starts from the power source and it ends at the PV system disconnect right and here's the way I explain it right and this is how I explained it to panel four when we were conceptualizing this stuff is that when you're standing at the PV system disconnect and you look toward the solar panels which is not the technical term but will just save the solar panels there's nothing but solar equipment between you and the solar panels alright there's no batteries there's no loads there's no nothing okay it's all part of the system all right the PV system disconnecting means is the demarcation point and that's what was so important about what we did in 2017 is to make sure that we understood where the PV system and started and ended because we're putting specific requirements not the least of which would be things like rapid shutdown which it was a big deal okay and we need to know where those rules start and stop because people get get very confused these last four figures that you've just put up on the board in the 2014 code we're all part of the PV system everything in that photo was part of the piece you had batteries in there and you had everything in now the circuits the whole nine yards all right let's look at it now so now you're saying that right up to this disconnect that's article 693 energy storage says don't tell me it's going to be 706 good job this standby is gonna be 7:10 where previously 690 kind of had all those things combined together which is very difficult now we have different articles addressing the unique conditions of those articles okay let me follow okay here's the PV system ends there so now we have energy storage connecting here so the electrons can go both ways right they can go out this way they can go in and out electrons go over here oh do people have DC panels absolutely what are you supplying well the FDC loves right you could have DC loads what's so ditch what's the voltage of a stand-alone system like these type of loads for standalone systems it can be anywhere from 12 volts would probably be the most common yes downloads let's go because RV the whole RV industry is built around 12 volts and so there's a lot of components so it's about a 12 volt okay got that and then I got the disconnect well then this is gonna have to go to my my pacer that's gonna be AC so that's gonna be AC and that's gonna be now is this 120 240 it could be it could be just 120 okay cool alright oh one second you know what I don't show you Brian I need you to show this panel grounded we need the ground this panel because at every building the building just gonna I don't know if even that's in the code actually to be honest with you but I'm gonna say this is a feeder coming to it so therefore I'm gonna say it has to be grounded all right AC modules and I find this interesting that back over here let me go to a better example interactive we had these individual modules or PV systems and they did all kinds of things to get over to the inverter and that's where we got AC out the blue right here where if you get a module then they actually put an inverter possibly on each individual module so now watch this you get a solar panel you have an AC module we have an inverter and interactive inverter because I'm gonna be taking that solar and interacting it with utility so now I'm taking whatever that both to just converting it to 120 volts but now I have hot Tory volts coming out and then I can plug these modules together and connect them in parallel so like let's say what's the amperage of an individual module 10 amps an individual single module was 10 amps yeah mm-hmm 40 volts 40 volts 10 amps something like that he'll mean I'm saying in the 120 both side what would it be at 120 both that when I connect how many can I put together a circuit it tells you 1 amp 1 amp on the AC so it's about that meant the same sorry it's about 1 amp on the AC so if I have a module and I have an inverter and it's let's say if it was 1 amp and I have a residential house of a 15 amp circuit well then I've run this cable from the manufacturer and I just kind of plug in 2 different ones and each one is converting the DC to one amp AC and I put in 12 of those on that circuit and then if I have another circuit I'd put 12 of those and I don't they have it where I can then make it a multi Y branch circuit where I can put them together so I just plug them in together and I just run this one cable here and I go put it on a two pole 15 at breaker it's correct right so you can just simply get the AC modules and you can get the cables and you just plug these things in together and then you just removed a whole bunch of code rules even wonder about because article 690 the only part of 690 that would apply is going to be the the inverter output circuit conductors and of course you follow the instructions and they tell you what size breakers so for all practical purpose they put AC modules you just plug them in together so these get all plug-and-play I don't know if we have any pictures of AC module about them play right which would be like they look like regular modules you you don't even know and unless you flipped it over so so I don't think I could see your screen Brian I think we don't have that set up there all right we'll have to set that in there so what we're going to show the difference okay so now let's say I plug and play all these things I connected here then when I make this connection here where is here I'm sorry good point love your face though if I connect the AC this is gonna be a hundred twenty volts because it's blue right it's see the Sun wave okay I connected here and I connect it here don't say anything to me trying to figure my articles so this is one power system this is the other power system interconnecting them together that I have to go to interconnected power production system that's article 705 right I can't think it we have to talk about I can't think of any rules on 705 anything special there and it says on 705 sure okay we'll get to seventy-five were talking okay I'm done with that that's a lot easier I noticed uh I guess in residential applications that that is this seem to be like a more common application as opposed to it's not more common it is a common it's a complicated all right so people any reason well but not gonna hold up [Music] you

Channel: MikeHoltNEC

Views: 35,463

Keywords: Electrician, solar, solar pv, photovoltaic systems, solar electricity, NEC Solar, Article 690, NEC, National Electrical Code

Id: gZT9y0Ougao

Length: 39min 21sec (2361 seconds)

Published: Mon Nov 02 2020