DIY Sub Panel Install: COMPLETE Tutorial, Save Thousands!

hi there I'm Nils and I'm going to be walking you through the entire process of how to install a sub panel a subpanel is just a circuit breaker box or an electrical panel that's used in conjunction with an existing main panel just a couple of housekeeping items is important that you work with the certified and licensed electrician on this entire process typically you are going to need to pull a permit so check with your city for local codes and ordinances to make sure that you're doing everything up to code and properly also in my case I've been working with an electrician to make sure that we have all of the correct information here it's all verified and I'm doing everything up to code with that in mind this video is intended as a help for it so definitely do your homework first don't just rely exclusively on the content that you see here I'll have a link in the description to my website where I've written up a complete article with charts diagrams and everything you need to help with that let's start off with space requirements in order to install a sub panel there are three measurements you need to be aware of number one you need 36 inches or three feet of space in front of the panel to work with number two you need to be able to have 30 inches across the panel there needs to be plenty of room for the door to open for you to access it or do whatever needs to be done in here and then finally you need up to 78 inches of height here this is the analogy I saw that I like if there's a telephone booth put up against the wall you need to make sure that this sits somewhere within that wall of the telephone booth the next part you have to make sure is that you have sufficient power to pull from in the main panel that you're connecting to in my case the main that I've got is actually right here so just you can see this huge wire right here just on the other side of this wall is the main for my house and I'll just be pulling from that right there just a couple feet away now not everyone will be so close and I fully understand that but you do need to make sure that there's enough panel space for you to put a new circuit breaker to run your new sub panel this is basically just going to be connected to that via a simple set of wires kind of like this one and then we'll make sure that everything goes to the right place when it comes time to select your actual panel that you'll be using there are several things to consider the first one is what brand you want to use my house uses Square D home line it's a very common setup here in the United States but there are other options too like Leviton Siemens Eaton and more but if you do have one already in your home you might want to use the same one maybe update to something like the Square D home line for example I've chosen a 2040 panel that means I've got 20 rows here to work with which means I should be able to install up to 40 circuit breakers I'm actually converting my garage into a shop and this is part of that process and I'm going to be installing a 70 amp box here now this box is rated for up to 125 amps and I'm only going to be feeding 70 but I'm wiring it so that it can handle at least 90 or 100 amps just in case I need to upgrade it down the line if you're somewhere in a detached space from the panel that you're feeding from then you're probably going to need a main breaker this box for example doesn't come with a main breaker and I don't need one in my case the next thing to consider in the planning phase of this is what gauge of cable and what type of cable you're going to be running from the main source to the panel itself as you saw before I just have a few feet to run so it's not as big a deal but you have a few different options over here we have an all-in-one cable so there's Ser cable and there's tray cable and both of those have a jacket that encloses all of the cables within them they come in multiple sizes multiple gauges and multiple counts of wiring but typically for a sub panel you're going to need four wires all together first one is you're going to need your set of Hots you're going to need two 120 volt lines coming in to your bars down here or right here and then the third one you're going to need is a neutral and that goes up top here and then the last one is a ground so it's a four wire setup now what gets a little interesting here is that you don't typically actually have to have the same gauge for your ground as you do the other three just to make sure I'm very future proof on this is I'm running two Hots in a neutral and then a four gauge ground and that should give me all the power and bandwidth that I need both now and in the future so you want to consider whether you do an all-in-one cable like this like the scr or the tray cable and in my case I'm actually opting to go with what's called THHN and that THHN allows me to feed it through conduit which I'm going to do entirely on the outside of the structure here can run right through those it's a little more flexible consider if you're going to have to run any of this through the studs I've got 2x4 framing here so I can't just run one of these guys through it by code since this is a load-bearing wall I can only cut a hole up to 40 percent of the depth of these which really isn't enough space for me to run a thick cable like this the other factor that you need to look at is if you are using conduit like I am you need to make sure that you have a conduit that's thick enough to account for the amount of wire going in it typically you can only fill it up to about 40 percent which leaves room for some flexibility and maneuverability in there now there is a cool app that you can get that's totally free it's called the Southwire wire fill calc I'll double check that and if I'm wrong I'll put that in the on the screen here you can put in what size conduit you're using what type of conduit you're using and then what kinds of wires and how many you're putting in of each and it will give you a rating on that in my case I'm going to end up using one inch EMT and I'm going to run that and it's going to be almost completely up to the 40 percent I usually like to give it more space but I'm having a hard time sourcing one and a quarter or one and a half inch and the one inch is still sufficient so that's what I'll be using in my situation there are a couple of things that are a little bit specific to my situation and I want you to know what those are so that you can calculate if you need to do those on your situation or not the first one is you can see right behind me I have my ground and I have my ground rod going down this is called a eufer and it's going into the concrete and this is actually the ground for my entire house so I'm actually going to tap off of this rather than feed my ground from the panel back here since this is right here and it's on this side of the wall I may as well use it and again that's what allows me to put the three two gauge wires into a one inch pipe because I don't have to add that fourth ground wire in my specific case the other thing that's a little bit different you may notice some of these studs are very close to one another typically studs are going to be 16 inches on Center in some cases 24 and in some cases like this 12 or maybe even a little bit less that's because whoever built this house they decided to do it that way but that creates some problems when most panels are about 14 and a quarter wide so that makes it tough to install so what I've done is I've reframed all of this and this is load bearing so I had to put jack studs headers the whole nine yards so a lot of you will have just a 16 inch on Center studs and you can slide that panel right in and keep in mind if that's not an option you can surface mount a sub panel if you do so you want to put some plywood on the back of it and fasten that plywood to the studs and then fasten your panel to the plywood so just keep in mind all situations are going to be a little bit different that's what I'm working with and that's why you might see things here look a little different than they are at your house or your business okay thanks for bearing with me through all that there is a lot that you do need to consider and research and understand before you jump into this now at this point I'm going to start working on the project itself and I'll just walk you through the entire thing as we go we've talked about a lot of the decisions already that were made so now let's get cutting installing and getting this thing put in the first thing I do here is use the tape measure to find out exactly where this box needs to be placed obviously I've got some framing in place to consider but I want to make sure that I'm meeting code as far as the space requirements that we talked about earlier and then I'm also looking at how far away the panel is from the existing outside panel and I'm using the main feed as a reference point to figure out exactly where this new one will go so that I can line up the exterior conduit that I'm going to be installing something to keep in mind with each of these projects is that you want to leave at least some open space either on the sides or the top or bottom the more open space you have on the sides of the panel top or bottom sides any of those sides the more it's going to allow you to use the Knockouts if you don't do that if you frame the whole thing in completely you're going to leave yourself in a bit of a bind and one thing I wish I would have done a little differently here is to actually frame this out a little bit lower so that I could leave the bottom open and the top open but as you can see right here it's really just the top that I'm going to be working with I wanted to have everything flowing through the central knockout as far as the source wires my two Hots and my neutral this so in order to do that I used to drill a hole right through from where this was placed right through to the exterior and then I was able to line that up once I had that lined up I could use a drill bit to cut a hole to the right size and I made sure to check the hole saw size against the connectors that I would be using and then was able to drill all the way through in my case you could see I had to drill through stucco some exterior boarding some OSB and in the middle there there's some chicken wire basically some wire mesh that I had to cut through and that definitely did a number on my drill bit because of that this whole Dozer bit this hole saw is pretty much destroyed with a hole in place I was able to put my lb conduit body inside the hole from the outside and that gives me access to basically a 90 degree turn in here then heading back inside I needed to figure out how best to mount this based on the thickness of the wall so I had some couplers I had some nipples and then I finally not at this early stage and then I finished off with what's called a chase nipple later on and that allows me to be able to pull all of the wiring through without any sharp edges or anything to rub on when you're working with the Knockouts in the Box just make sure to only take out as much as you need they're pretty easy to remove you can just use any hard surface to tap them off a little bit and then just use some pliers to shake it free and with that I had a beautiful fit for the sub panel and I was ready to move on to the next step next I needed to cut the one inch conduit to size and I wasn't sure exactly what that length would be until I got everything test measured so I put everything in place I'm using Rain Tight connectors here to make sure that I don't have any precipitation getting inside the run and then I got my 17 inch measurement and then I decided to use just a metal blade on a hacksaw to be able to cut that to size you always want to cut a little long I know I wear shirts sometimes that say I only measure once but I usually do measure twice it's kind of a joke but then I wanted to make sure I had a little long in case I needed to cut it shorter later make sure to remount the ends so that you don't have any sharp bits of metal inside your conduit as far as connecting to my main panel I I open it up just to make sure that everything was looking good and that there was an area that I could drill a hole into without disturbing anything the last thing we want to do is to drill a hole into some of the wires in there that could wreak all kinds of Havoc as for drilling the hole itself I picked up a set of these fairly inexpensive hole saws that are meant for drilling through steel stainless steel or plastic and they're really just perfectly made for drilling into an electrical panel in fact you can see the image on the bottom right of the packaging that shows exactly that and this worked out really well with the hole in place I was able to do a proper test fit to see how this would work out and it turns out my 17 inch measurement was a bit long so I did need to take about an inch off and then with that I was able to Snug everything into place and then tighten all my rain type fittings down I love using this set of Klein offset lock nut wrench tools to make it really easy to tighten those Rings because otherwise you have to use a screwdriver and tap it or find some other way but these just grab right onto it and make light work of it I then use my channel locks to tighten everything down a little bit more just to make sure it was completely snug and this conduit was ready to go next up I installed that chase nipple that I referred to earlier that has the nice soft Edge on it and then started getting my measurements for exactly how far I needed this to stick out now I'm going to have my panel sticking out quite a bit further than most other people because in this shop I'm actually going to layer the entire walls with both OSB and 5 8 inch drywall so it's going to be a little over an inch in depth so I needed to get that measurement just right on all four corners before installing it now as a result of that I couldn't use the Knockouts which are supplied in the Box for mounting it on the sides I had to actually drill my own and then install it that way but that worked out just fine and now I've got a nice even stand out all the way around next up is the fun part and that is feeding the wires through now these two gauge wires are pretty rigid they're kind of hard to move into position but I wanted to get everything ready so I just stripped off about half an inch of wire at the end of each one and to do that there's a couple of ways you can use a blade and just very carefully and lightly score that and then pull the end off or or you can use the wire cutters themselves which I have built into my strippers and then just score around that way and pull it off either way should work but what we want to avoid here is cutting too deep and fracturing any of the wires inside the cable carefully measure out exactly how much wire you're going to need for everything and always give yourself a little extra room to play with so this is really just a matter of fitting three separate wires through here and again I'm kind of maxing out this one inch conduit here but I was able with a lot of finagling and back and forth to get this done I found it helpful to connect everything on the sub panel but not connect anything on the source panel just yet I don't want to bring any power into here just yet I just want to get it ready so that when I want to everything's at the right length once I had my lengths approximately cut in place and then the ends of them stripped I decided to connect them up to the 70 amp breaker that would be feeding the indoor sub panel I did not connect the breaker I just got the wires connected into it so that when I was ready I could connect that to my source panel and flip on the power with my two gauge wires and place inside the box I use some electrical tape to Mark the neutral and the second hot with white and red respectively now you'll need to install the bus bars that come with your panel these are for the grounds you can place these anywhere you want in the panel as long as the holes line up and you'll see that there's some little studs that protrude from the back of the box that you can use to line them up or you can just use the two holes inside there and I prefer to do that so that there are two screws fastening each bus bar to the panel the two Hots and the neutral were already connected but I didn't have the ground connected so I connected that to the rod that was right next to it the eufer we talked about earlier and then I was ready to connect it to the panel itself so I made sure to use a metal connector inside a knockout on the top and then brought that ground in before turning the power onto any of this or connecting all the way to the source I decided to install these service entrance covers over the two Hots and that just makes sure that I have everything covered up because right now everything is very exposed so this keeps me protected and I'm going to leave them in there permanently and that will help me or anybody who works on this us in the future to not have those exposed now for the Moment of Truth outside on my source panel I'm uninstalling the 20 amp circuit breaker that was powering the single line that goes into my garage and I'm replacing that with the new 70 amp circuit breaker but you'll notice I'm leaving it in the off position right now while I check everything while that 70 amp circuit breaker is still off and no power is coming into the sub panel it's time for me to run my first home run or my first line from the new sub panel out to what I'm going to connect it to which is basically just the old line of the garage this will power a couple of outlets and then the garage door opener itself for the purpose of this video I won't be getting into all the details for how to connect this up because this is more of a separate topic but generally speaking I'm going to strip the sheathing off the wires separate everything out measure it and then Mark them all down to where they need to be I'm going to connect my ground to my ground bus bar my neutral to my neutral bus bar and then the black in this case which is the hot I'll connect that directly to a 20 amp circuit breaker I also have a secondary one because this is 12 3 Romex and I'm just letting that second one kind of hang out in the Box for now because I may run a 240 volt on that one if I want to later now I'm also installing this circuit breaker on the bottom right which is a little bit unusual because this is a temporary one so I'm just kind of leaving this separate just to indicate that this will be functional but it's temporary okay so at this point I have connected one 20 amp breaker to the new sub panel we have everything here going into the main panel The Source panel but it's not flipped on on the 70 amp breaker outside so if I flip that one on and then flip this one on this connects to the outlet over here the receptacle and this is a GFCI this should be ready to go and we'll power everything else in the garage that used to be powered on the old panel so for the outside panel by itself fingers crossed let's see how this goes okay we now have power to the box so now I'm going to switch this on we now have power to the line and check it out we also now have a green light and 124 volts ac coming through so that was a success we now have a dialed in and ready to go sub panel that's fully functional that's pretty rad now the hard part is done we have power everything is wired up just as it should be it's working perfectly and that again is kind of the turning point of this entire install we just have a few steps left to finish up we're definitely not done at this point so the next thing we want to do is to install our sticker that comes with this that talks about the torque ratings for each of the lugs and screws inside the panel so I'm going to apply this Inside the Box on one of the sides where it's not likely to get covered up and then I'll go through and we're actually going to torque down each of these lugs I only have a few to handle here which is pretty nice but I'm using this guy right here this is a torque screwdriver these can be purchased pretty inexpensively I'll put links in the description where you can get one of these on Amazon for right now they're about 40 to 45 bucks that may change when you see this video fine make some and those are like 300 bucks they get pretty pricey but I found that this one does a pretty great job for me so I'll be torquing each of these down to the right specifications and then after that we'll be ready to put the panel on just after we do a final inspection to make sure everything looks clean and ready to cover up as per the specifications directly on the Square D home line circuit breaker this requires 36 inch pounds of torque when using the Torx screwdriver basically you just turn this thing until it gives out and when it gives out it'll just loosen up and you know it'll click as well and that means you know you've got it to the appropriate torque rating I can pretty quickly adjust the torque that it's going to exert just by turning the handle pull down and turn get it to the right setting and then use it the bus bars inside this panel require 20 inch pounds of torque so I'm going to fasten each of those down as required and finally the larger slotted screws which would be the neutral and the two Hots plus the ground those each require 50 pounds of torque so that's what I'm applying to those again these are specific for my situation so make sure to check the manufacturer's recommendations for the subpanel that you're using with everything wired up and torqued down appropriately I wanted to make sure that the entire panel was totally clean you cannot have anything else in this panel you don't want to have any flammable items obviously but anything else I've cleaned out the bottom of it and then that extra second hot the red wire that you see over on the right I've got a Wago on there to terminate that it's not connected to anything on the panel or on the other end it's just there for when I want to use it later and so it's okay to have those terminated inside the panel so long as they're not connected to anything before putting on the cover I decided to put just a couple of open circuit breakers because the panel comes with the top two slots knocked out already rather than leave those open I just put these in as temporary placeholders so no one can put their fingers inside those open slots speaking of open slots I had to knock out the bottom right one which I was using and it's pretty easy to do you just put a little pressure on the panel and then grab it from the back and then rocket free so this panel is now complete the sub panel is installed everything's looking good except for one little thing and this is kind of annoying but the manufacturer made this with four extra slots down here even though there's no place on the board beneath it for those to accommodate any circuit breakers so thinking it was the bottom one I knocked that one out and now that's not up to code I need to put a filler plate in there which I'll have to go purchase and do but other than that this thing is ready to go I actually have a couple of empty ones in here just for the moment I'll be filling these in later today because now that I've got this panel ready I can start running all of the electrical wires I need for my garage shop here so that is the point of this I'm going to run lots of wires in here I've got my connectors going in here and I'll be using all metal ones everywhere in this box just to make it easier to work with in the future and then everything I'm doing in here is going to be as future proof as possible now there's a lot that we covered today there's a lot that you want to check out not only with the National Electric Code but also with your local code that could be in your city your county or your state depending on where you are so be sure to to check that out as well now I've got a lot of helpful resources on my website to help you out with all of this including a dedicated article with all of the products and tools that you saw in this video as well as some of the gauges and charts that you're going to need to figure out what to use for your particular application and then step-by-step instructions of the entire thing again use the link in the description below to click on that if you want to go check that out and that will help walk you through the entire process if you have any other questions or anything feel free to leave those in the comments below if I missed anything or you saw a better way to do something again help us out with the comments below and that will help everybody to do a little bit of a better job my name is Nils with learn to DIY thanks for watching

Channel: LRN2DIY

Views: 145,692

Keywords: diy, how-to, lrn2diy

Id: uThjbVDcpxo

Length: 20min 34sec (1234 seconds)

Published: Sat Aug 05 2023