When and Why to separate Grounds and Neutrals.

hey everyone welcome back I am the electrical code coach and as tempting as it may be I have to remind you to not repeat anything in these videos use them for educational purposes only I do want to note that there are previous code cycles that allow the neutral and ground to be bonded and if you were to go back and try to disconnect those without contacting a qualified electrician you could be actually be creating a larger Hazard let's get to it all right y'all today we're learning about when and why to separate grounds and neutrals I feel like this is one of the most misunderstood and just underappreciated parts of the code so hopefully I'll bring clarification very quickly today I don't want to waste any of your time so first let's learn about when when do we separate grounds and neutral let's go ahead and take a look at it we must connect the grounds and neutrals at the first point of Disconnect we must separate grounds and neutrals at every other point in a standard electrical system we must connect the grounds and neutrals at the first point of Disconnect and we must separate grounds and neutrals at every other point in a standard electrical system all right let's go ahead and take a look at a couple real life scenarios so let's imagine that we installed this new meter out here it's a meter only and then we went back to back and we installed a regular electrical panel pretty standard setup well this would actually be our first point of Disconnect and we must connect all the grounds and neutrals in this panel I've taught you in previous videos how to bond the can and establish that connection and that's called your main bonding jumper remember it was the green ground screw that you screw in or sometimes it's actually a bonding strap that goes in these panels and that connects the grounds and the neutrals um together and also to the can now let's look at another scenario let's imagine that you put a meter disconnect combo like this now this would actually be our first point of Disconnect and we must connect all of the grounds neutrals together at this point and at this point only and let's imagine we come into the house and we install our standard electrical panel or or our commercial building it doesn't matter at this point this would be our second point of Disconnect and any point past that first point is considered what we call in the field a subpanel and every point in an electrical system past the first point of Disconnect we must separate grounds and neutrals no matter what there are very little exceptions in the code and it has to do with drers and ranges and that is a very limited and it has to be grandfathered in from previous but when we're talking about services and bonding grounds and neutrals anywhere in the system if we're doing a meter back to back this would be our first point of Disconnect and we must connect the grounds and neutrals if this is a meter disconnect combo or if you have another disconnect outside underneath your meter then this would be your first point of Disconnect and you must connect grounds and neutrals and at this point and at every Point past that you must disconnect the grounds and neutral connection all right y'all we can't stop there now it's super fundamental to know when to separate grounds and neutrals but I don't want anyone to be average around here I want you guys to be pro- diyers and pro electricians at every stage in the game so we must understand why we separate grounds and neutrals now let's go ahead and take a look at it we've been told our whole life that current takes the path of least resistance okay and and that has some truth to it but the truth is is that electrical current can take any and all paths back to the source that it is connected to and it will it'll take any and all paths now the Lion Share may go on the path of lease resistance but as the scenarios that we're getting ready to unfold the wire may not be the path of least resistance there may be another component in the system that's offering a whole lot less resistance and the current can actually flow on it now let's take a look at the scenario here let's imagine that we have this meter disconnect combo right here and this is our panel inside the building and we ran a piece of rigid metal conduit in between it okay and we ran our two Hots our neutral and our ground over to our panel and let's imagine at first that we did connect the grounds and neutrals here and we did separate the grounds and neutrals here everything's good this is a proper system as far as this goes now let's take a look and let's imagine We've ran some wire out of this panel pretty standard and let's say out of this circuit we head out we head to this light bulb here and the current should flow in on the hot come back on the neutral back on the neutral and then leave on the insulated neutral conductor all the way back to the source at no point was that current leaking anywhere else and it was heading on the path that it should now this is the beautiful thing this is how it's supposed to be designed we've connected grounds and neutrals here we've separated them here current leaves the breaker it comes in on the hot pin leaves on the neutral pin of this light bulb after it does its work comes out leaves back all on an insulated conductor in insulated setup through here and then it comes back on the insulated neutral back to the source okay or on its way back to the source that would be be a beautiful setup now let's imagine for a second if you did not separate the grounds and neutrals okay in this little scenario that we have here current is going to leave the breaker it's going to come back on this neutral but it's also going to want to flow back when it gets back here to the source if it didn't catch anywhere else here it's also going to want to flow back on the ground wire all the way back to the source because if you connected the grounds and neutrals here is going to flow on any and all paths back to the source well you say that's not a big deal maybe it's an insulated green conductor and it wouldn't matter anyways well unfortunately that's not the case because in these neutral and ground bars you also connected the metal frame of the can like we're supposed to just in case there's a short it would trip the breaker right we've learned about that in the past so currents actually going to flow on this metal can as well also it's going to flow on the metal conduit all the way back to the source so instead of the current leaving the breaker hitting the neutral riding back on an insulated conductor all the way on its path back to the source it left the breaker hit here could have flowed on this metal box back flowed all the way here would have hit the can all of the metal components here could have temporarily flowed on any one of the bearrs inside of that panel it would have flowed back on the ground and the neutral conductor and on the piece of rigid metal pipe coming back to the source and anything else metal it was touching on the way back if this was mounted to a metal stud building it could have flowed on the metal stud building on the way back all right y'all let's take a look at a large setup and understand the true dangers of not separating the grounds and neutrals past the first point of Disconnect so when we left off we were in this perfect scenario weren't we we were in the did connect did separate neutral currents only flowing back on this insulated conductor Life's good no worries but let's imagine that you did not separate we just learned a second ago that current would flow on this can on the metal and both of these conductors all the way back may not be a hazard it may be but now let's imagine that you installed another sub panel and you did not separate and this is very common in homes okay so let's imagine here and let's imagine coming out of both these panels we had circuits now I'm only going to be drawing the equipment grounding conductor leaving from these circuits because that's all we need to focus on today of course every one of these would have Hots and neutrals leaving the panel too but we're just going to draw the equipment grounding conductor so let's imagine we come out of this panel and we come over we come down we're going to have receptacles and potentially Lighting on this circuit that's a metal lighting fixture okay and let's say we came out of this panel we came down we also had receptacles and we came over to refrigerator pretty standard situation now every circuit that leaves this panel is going to have an equipment grounding conductor coming with it in modern wiring and in lots of old wiring and all of these ground connections are likely going to be bare you know bare conductor and they're going to be touching multiple metal points all over your system these two circuits could have their grounds connected somewhere Downstream you know and these two circuits could have their you know circuits connected Downstream the grounds and these two here so these could be multiple interconnected and actually that's what we want we want all of the grounds in the entire system to be interconnected very well so if there's a fault anywhere in the system it's going to quickly clear the fault but let's imagine we come out of here and we have the ground wire coming over here to our dryer all right now here the stage is set this is a pretty typical house and we're ready to go now at a minimum if we did not separate here and here okay the issue would be at a minimum we would have from all of these circuits here and all of these circuits here the current would flow back on this metal can on this ground conductor this neutral conductor this metal pipe this metal can these two conductors here and this metal conduit at a minimum and every other thing that they touched uh and connected with metallically okay on the grounds meaning any of these grounds that went out from this panel anything that they touched if it was in between that point and the source it would flow on could potentially flow on all of those back okay and that is like the best case scenario the reality of it is is that current's going to flow potentially on any and all metal components and conductors on the way back to the source every single one of them including the shell of your refrigerator including the shell of your chandelier all of these bare ground wires and everything they touch in between you could have current flowing on it okay measurable current flowing on it okay and this is just super important also includes our metal bathtubs metal showers metal water piping and every single thing in between we could have current flowing on it that's why it's super important that we separate grounds and neutrals all right y I hope you guys really enjoyed today's video and I hope you have a full understanding of when and why to separate grounds and neutrals just remember that we must connect grounds and neutrals at the first point of Disconnect only and we must separate grounds and neutrals at every other point in a standard electrical system I am the electrical code coach I'm here to help you in any way that I can you can email me at electrical Cod coach atgmailcom let's get to [Music] it a

Channel: Electrical Code Coach

Views: 244,317

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Id: _v_vcTqD6zk

Length: 10min 32sec (632 seconds)

Published: Fri Apr 29 2022