How to Safely Replace a Ceiling Light | Ask This Old House

[Music] hey heath hi brette nice to meet you likewise come on in so what are we looking at today so the light that i emailed about is actually right here okay so we've been in this house for about three years i'm pretty handy so i thought i'd replace this light fixture we bought a light to replace it and there's a warning label that i really wanted to have some look at before we put it in sure let's take a look at the fixture so this is the fixture that we bought right here all right oil red bronze finish the clear glass the edison style led lamps nice looking fixture thank you we love it but the warning label here said that for houses built before 1985 that there's a risk of fire this house was built in 1960 ah got it so what we'll do is we'll start by taking the existing fixture down we'll take a look and see what you have for wiring up there but first we'll go downstairs and you can show me where the panel is we can turn the power off great follow me [Music] [Music] all right so we've taken the light fixture down okay and what we found in the junction box was pretty much what you expect to find in a house of this age it has this kind of cloth covered nm cable and the conductors inside are rated 60 degrees celsius or about 140 degrees fahrenheit okay the drawback to this is when you'd have a fixture that would take an incandescent bulb people would often put a lamp in that the fixture wasn't rated for something much higher that could generate a lot more heat what would happen is because this only had a lower temperature rating it would actually heat up over time it could get brittle it could crack it could separate and fall off worst case scenario though it could actually r can cause a fire and that's the last thing we want to have happen right so in the early 80s they actually changed the code to make the temperature rating of these wires higher okay and what they've done is they've required the insulation on this jacket to be rated 90 degrees c or almost 200 degrees fahrenheit 194 degrees takes a lot more temperature and gives you a lot more selection as far as putting up fixtures and installing different types of lamps so does it matter that these are led bulbs they're not going to get that hot right no the bonus is those really won't generate anaconda heat but the only drawback is because of the type of socket it is it still takes a standard bulb that you normally get anywhere and there's still the potential for someone to put in something they shouldn't something that's way too strong that still could overheat so what we can do to solve this issue is we can splice a piece of wire pull the existing wiring back add a new piece of the newer wire about 18 to 24 inches long put that in the junction box and that'll let us install the new light fixture you picked out awesome all right we're going to start by getting these old wires out of the way and we have a little crawl space above us and we're just going to push these up into that crawl space all right so what we have here brendan is we have the wires that we pushed up from the light fixture downstairs yep the problem we run into is they go in different directions so they don't quite reach one junction box like we hoped they would okay it's okay we can fix that what we're gonna do is put one wire into this first box bring these two wires into the second box put a jumper between and then we'll run the new wire down to the fixture where it was before sounds good all right so here's the wire we push down from the attic okay this is our new one and now we're going to install the new box so next we're going to strip the jacket all right and now we'll slide the wire through the cable connector and then we'll slide the box up and now we'll put the ground screw in now we're going to go around that ground screw on the fixture bar as well is there a reason why you're putting in a second ground screw in this case where the box is metal and the box is already bonded the fixture bar is attached with metal screws that's usually sufficient but in case the box was plastic you definitely want to attach to this and it's just a habit we've always had in a good little extra practice to do we're ready for the fixture all right here you go [Music] [Music] all right and let's install the light bulbs all right and now the glass sit like so and then we'll take the ring all right the power's back on let's give it a try looks great it's a great looking fixture and i feel really good knowing that it's safe glad we could help awesome thank you very much heath really appreciate it nice job heath although i've got a question for you what is the 18 inches by you i mean if you're still pulling too much power what do you guys call it amperage if you're still pulling too much amperage over a wire couldn't heat up anywhere along that run it could but the amperage actually isn't our concern and what we're trying to solve here the issue with this is lamp issue and heat from the lamps and potential of overlapping that's where we get the heat problem wait so it's because the bulbs are close to that junction box that's what's causing it exactly because this is sitting right on the junction box and you have the heat source directly against it it can actually heat up inside that junction box make the insulation the conductors brittle and has a breakdown so if the bulbs are farther away we wouldn't necessarily have the problem like a chandelier if we had a chandelier where the bulb source or the bulb was actually lower heat sources away from the canopy not as much of an issue and you might not see the label at all and they may not have a tag on it all right so when you open up that box and you see the wire you know what's right and wrong right how do i tell whether it's the right wire or not so the first thing to take a look at is this one is obviously old so we know right away there's no chance of that being rated for today's fixtures and that's because of this this because of the jacket and the way it's wrapped yeah you can tell right off the bat so this one is never good in this situation not for this application okay then they change to this sometime in the 70s we'll see something like this non-metallic sheath cable type nm right and it says that it does say that right on it type nm but it's still only rated 60 degrees celsius same as the other one but in 1984 we went to this one well how do you tell the difference between these two because they look a lot alike and the difference between these two is the nm versus the nmb nmb 90 degrees celsius and the b is just like second generation essential second generation okay so if you pull it out and you don't see nmb you know that it's not good for this application that it's 60 degrees c conductors inside there and any wires we buy today are going to be rated for the we'll have that be on there and it shouldn't be an issue cool great information thank you thanks thanks for watching this whole house 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Channel: This Old House

Views: 469,621

Keywords: This Old House, Ask This Old House, DIY, Home Improvement, DIY Ideas, Renovation, Renovation Ideas, How To Fix, How To Install, How To Build, electrical, Heath Eastman, lighting, ceiling light, 7-10 minutes, How to clips, how to videos, This Old house videos, Ask this old house videos, master electrician, temperature rating, temperature rating system, ceiling lights, homeowner, Eastman, 60 degrees Celsius, 90 degrees Celsius, Type NM, Type NM-B, Plastic wire, screwdriver.

Id: 2I8BMtTbzJ8

Length: 8min 18sec (498 seconds)

Published: Mon Jan 27 2020