Electrical Testers – Home Improvement Podcast



welcome to fix-it home-improvement covering projects that every homeowner should know and great products for home and garden today we're going to talk about electrical testers and we'd like to thank Bradley Templin for liking and sharing the podcast and we'd also like to thank cast box for featuring us again in their education section and if you're looking for a good podcast app for an Android device you can check out cast box and it's CAS T Bo X in the 1920s one of the first commercial multimeters was designed to look like a packet watch and pocket watches in the 1500s only hit in our hand to give you an idea of the time they didn't add a minute hand until the 1600s so a pocket watch has a hinged cover that would open so you could see the time or it would have grillwork to protect the moving parts it wasn't until about 1610 when glass was used to cover the face Wow yes some of the first two handheld digital multimeters were made by the fluke company FL uke in the 1970s for doing electrical projects around the house the three main testers are an outlet tester a non-contact Electrical tester and a multimeter and there are other testers like a clamp meter that has jaws to clamp around wires and you're measuring current but they're mainly for professionals so an outlet tester plugs into an outlet as lights that light up that lets you know whether the outlets on it also can do other tests and what I like about an outlet tester is if you're working on that circuit you can plug this in the lights light up and then you run to your service panel and turn off the power to that circuit and you can look over and immediately know whether the powers off rather than having to get you know a traditional test or go in and put probes into the slots in the outlet so it just makes it fast to find out whether the powers off to that circuit and outlet tester is also going to let you know whether the hot and neutral wires are wired correctly so you have the high to either the black or the red in most cases going to the brass screw on the side with a narrow slot and the neutral wire or the white wire is going to the silver screws on the side with the longer slots in an outlet so if an outlet is wired in Reverse which is called reverse polarity it can be a shock hazard with lamps so the lamp is going to turn on and off but when it's off the socket is live and can be deadly into the right conditions and it's also going to let you know if you have a disconnected neutral or a ground wire that's going to have a label on the tester itself and usually you're gonna see it labeled with an open ground or an open neutral and whatever you see open that just means it's a disconnected wire hmm some outlet testers are gonna have a button so you can test a GFCI and you should be testing your GFCIs once a month if they're not self testing like with outlet tester yes so you're gonna plug in the outlet test you're gonna press this button and it's going to see whether it shuts off in a fraction of a second if there's a yeah and you should be using the test button to anybody do that no you're supposed to do it once a month and they found that people just aren't testing them and all GFCIs fail over time and red manufacturers are recommending that you replace your GFCIs once every 10 to 12 years so GFCIs after 2015 are now self testing 10 extend and they'll shut down when they fail at the end of its life and read the instruction it's completely dead because you don't have the protection anymore so the old ones if you weren't testing it you thought you were protected by a GFCI but it's still working like an outlet but it can be a shock hazard so the new technology they're actually much safer but I would look at the GFCI when I install it some of them blink you know when it's at the end of its life some of them a light just comes on continuously so you need to know what manufacturer what what could talk really eventually soon so it's interesting about the outlet testers with that button for the GFCI is it's using the ground to test the GFCI to confirm that it's working and it's not going to work on an ungrounded GFCI so if you have an older home that doesn't have a ground wire and you just have like the old outlets with just two slots it doesn't hit the ground hole you should replace it with a GFCI and it's going to be much safer but if you take a GFCI and it's ungrounded you need to use one of these labels that come with a GFCI and it says no equipment ground and if you don't have that or if you've rewired a GFCI like this and you didn't understand this so if you have an ungrounded outlet that's that your safety so if you so it's going to prevent you from getting electrocuted but it's ungrounded but a GFCI if it senses an imbalance between the power coming into the GFCI and leaving on the neutral wire if your grounded if the electricity is trying to go through you in a fraction of a second it's going to turn itself off it's going to use the internal breaker and it's triggering if there's an imbalance of 4 to 6 milliamps and a shock as small as 4 amps under the right conditions can put your heart in fibrillation and potentially cause death so it's smart if you have a older home with only 2 slot outlets there's no ground on your outlet so you can replace that with a GFCI and it's going to be safer but you need to label it so that everybody knows that there's not a ground on this because when you put that GFCI in it's going to have an a ground slot you know it's gonna hear the two slots plus that's circular ground but like it like a net outlet if you put a surge suppressor in there the surge suppressor needs the ground to actually operate so now you don't have a surge protector you only have a power strip how many outlets is a GFCI protecting so it depends on the manufacturer many of the 15 amp GFCIs are gonna protect 10 outlets on the load side or a lot of electricians would call that downstream with a 20 amp GFCI they protect about eight outlets downstream so if it's not like the first outlet in the circuit it's not protecting anything yes it's everything past the GFCI so you need if you take off multiple if you're replacing multiple outlets or let's say you just want to replace a see I and you want to protect everything else in a circuit you're gonna have to take all the outlets out and then test the wires find the very first hot wire that box is going to be the first box in that circuit so you put your GFCI there everything else downstream is going to be protected so you don't need to buy more GFCIs right you just need one GFCI and then everything on the load side is going to be protected hmm since we're talking about ungrounded outlets if you never holy be talking about so if you have a the outlets with just the two slots so you don't have a ground on it a lot of times you're using the adapters that go from a three prong to a two prong and on that cheater plug they call it there's a little metal tab that you take out the screw on your outlet cover you plug in this three prong to two prong adapter and then you take that screw and you screw down on that little tab on the plug so this isn't code in some areas and the previous style so the old three prong to two prong adapter had a grounding wire rather than that tab and what they found was that wire got pushed into the hot slot on some outlets and it actually caused a few electrocutions so they discontinued those you can't get those anymore in effect in 1969 only half of the receptacles were three prong in the US Wow and in 1971 all new construction was required to have grounded outlets so with that three prong to two prong adapter if your home is conduit or has flexible metal conduit and the conduit is grounded all the way back to the service panel when you use that Center screw for your outlet cover and screw it into that tab it actually grounds it which is interesting but if you have nonmetallic cable with no ground so you've an older home with nonmetallic cable then that is not a ground and if you want to talk about using a multimeter if you take a multimeter with two probes and you put the black probe into the narrow slot which is your hot and you touch the red probe to the center screw on an outlet that's going to let you know let's say you have a two slot outlet by testing from the small slot to the center screw you'll know whether your you have conduit or not or whether it's grounded all the way back to the service panel a non-contact Electrical tester will let you know if you have electric on a circuit without getting dangerously close to live wires and there's two main styles one that's just always on and then one that has an on/off button some models are going to show you a range of voltage levels with an LED light some are going to have sound and light to identify Hotwire and some just light up and it's always good practice to test a known live circuit to verify the non-contact testers working and then use this to test your project and then recheck it on a known live circuit and that way you know you're guaranteed that the battery didn't accidentally go out during the process and you know what trick you can do if you're trying to test your non-contact Electrical tester to make sure it's working mm-hmm you can just rub it against your hair and the static electricity from your hair will actually test it whether it's working or not yes he did this yesterday as the coolest thing ever wasn't some non-contact electrical testers have built-in flashlights which is very convenient and I just did a project where I was trying to find a disconnected neutral wire in a circuit and I find it oh man it took me a long time but I was looking for this and the one box that I was looking into I used a non-contact Electrical tester to test the outlet before I removed it I turned off the breaker that outlet was dead so I knew I got that circuit I pulled the outlet out I started separating all the wires and because it was a big box it was like a junction box I took that non-contact Electrical tester and I pushed it into the back of the box and there was actually another circuit going through this box so there were live wires in the back of it and if I would have just started disconnecting all these wires it could have been a shock hazard and no more podcast so you know a non-contact tester is really nice because you know rather than having to take wires apart and in especially this was deep in a box I knew immediately there was another circuit I had to turn off a non-contact testers gonna make it easy to find the hot wire when you're working on switches if you're trying to find the fee wire or the common wire for example on a three-way switch and then in older homes if you have insulation that's all the same color it's going to let you know very quickly which one is the hot wire so you can mark it one of the problems though with non-contact testers is most of them don't detect low voltage for what if your or thousand right thermostats exactly multimeters are gonna come analog or digital for electrical projects around the house a multimeters gonna allow you to test ACDC and continuity so AC is alternating current and you're testing your household current so switches outlets and lights at 120 volts right it's gonna also test 240 volts to appliances like a water heater DC is direct current and you're testing batteries cat annuity is testing to see if current is flowing through something like a fuse or switch an analog multimeter is inexpensive and very versatile it's going to have a main knob to choose between the settings and ranges and displays usually going to have four ranges you've got two probes an insulated area behind the metal tips and one of the probes is going to be red one's going to be black the red is positive the black is negative the display is very confusing if you don't know what you're doing what's funny when you look at it it's almost overwhelming it's going to have all these numbers and symbols and lines different colors but if you just look at the number at the end of each range it's actually very easy to figure out so a common analog multimeter is gonna have four ranges it's going to start from 0 to 10 on one line 0 to 50 0 to 150 and 0 to 300 and then around the knob you're going to have an area for DC V so direct current volts and it only has four settings so the numbers are 10 50 150 and 300 which matches up to the last number of the ranges on the display and the same thing you're gonna have four settings for a CV so alternating current in volts and it's 10 50 150 and 300 and you might have milliamps DC I've never really used that for projects around the house and then you're gonna have an ohm setting for continuity so om so to give you an idea how easy they are to use if you're testing batteries let's say you're testing double-a is triple A's C's or DS those are all 1.5 volts you're going to turn the knob to the number just above what you're testing so in this case with this multimeter we would turn our knob to 10 DC V and we're only looking at the range on that display that ends in 10 we don't care about any of the other numbers or colors or ranges and when I touch it's in your range it's an arc that it goes on right right right so when you're looking at it you've got 0 2 4 6 8 10 for example it's got all these little hash marks in between us so you're just paying attention to that one right because above it you've got 0 250 above that 0 to 150 and 0 to 300 exactly how easy yes so that pointer or the needle if you touch it on the two ends of your batteries should be between 1 and 2 in that range and you don't care about anything else on it if you want to test a 9-volt battery you would turn the knob to 10 DC V so just the number above what we're testing and it should end right at 9 if you're testing a car battery at 12 volts for example you're gonna turn the knob to 50 DC V so direct current and you're only looking at that second range that ends in 50 so it's it's pretty straightforward if you're testing an outlet or a switch at 120 volts you're gonna turn the knob to the number just above what you're testing so in this case we've turned it to a hundred and fifty AC V and then we'd read that range that ends in 150 to test 240 volts we would turn the knob to 300 AC and we're only looking at that range that ends in 300 so very easy to use this to test a fuse you're gonna turn the knob – Oh hmm and this uses the internal battery to see if current is flowing through the fuse so if a fuse is good that needle is going to go all the way across the range to zero on the range marked Oh hm and you can see on the opposite side of the other zeroes right yes so if you're looking at the display for all of the other settings zeros on the left side for Oh hm zeros on the right side just to make a little confusing yeah so you can also test switches if they're good you can put the probes on the screw terminals and turn it on and off for like a single pole switch on a 3-way switch you would test from the dark colored common screw to each one of the travelers flipping the lever up and down one is going to be operated with one screw terminal the lever the other direction is going to be the other screw terminal that's wired no no you wouldn't in fact you would never when you have your multimeter on ohms you're using your internal bad or you never want to plug this into anything that has live current or you'll destroy your short out your multimeter it's important to say thank you so whenever you're testing a switch this is the switches not connected and you're just testing the screw terminals you can also use the ohm setting to see if there's a short between the hot and neutral or hot and ground if the installations melted let's say behind the wall and the wires are touching this is gonna show up when you test so let's say let's say we've removed a couple outlets and we know there's a short somewhere why would you know that because a breaker keeps tripping okay so like this project that I was working on I knew that there was a problem with the neutral wire somewhere really should be taking advice from you well I did solve it so then so we turn it to continuity so ohms our meter we have the electric off and now I can touch the black and the white wire on one cable at the same time if I have the outlets off and I touch those two wires if the wires are good I'm not gonna show any continuity my needle will not move okay but if the wires are touching somewhere behind the wall and I touch the hot and the black or the hot and the ground and it that needle goes all the way across to zero I know that the wires are bad somewhere behind the wall so I can isolate what section of the wire I need to work on if you have a digital multimeter sometimes you're gonna have a CDC and OAH em on it or instead of that you could have a V with a wavy line over it a V with a solid line and three dashes under it or an Omega symbol because that's not confusing boy first time I saw it I had no idea so the Greek Omega symbol was used around 800 B see is the last letter in the Greek alphabet and it looks like a really fancy upside down you write and the lowercase Omega symbol looks like a lowercase W weird isn't it totally and they use that symbol for ohms so it's a unit of electrical resistance and it was named after the German physicist George ohm net cool his last name is o hm what are those symbols mean so if you have the V with the wavy symbol that's alternating current if you have the V with a line and three dashes under the line that's direct current yeah and then the Omega symbol is either testing resistance or continuity and your displays saving that much room by not doing just an AC well this is for professional Cindy so your displays gonna have digital number readouts and your settings around the knob can have more or less settings so volts for example may just have two hundred and fifty and two hundred but the key is always turn your knob to the number just above what you're testing right and you won't have a problem and some of the digital multimeters are also going to have settings with different symbols like the Soundwave symbol if you're testing for continuity and it's just gonna give you a sound if there's continuity rather than rather than reading a range where it might have that diode symbol and I like that sound setting for projects like lamp repair so if you're changing a lamp cord or a socket on a lamp and you don't know which side of the cord is hot and which is neutral you can put it on your sound setting and touch one probe to the narrow plug and that narrow plug is your hot the other side of the cord you're gonna have two wires touch each wire and the one that makes the sound is connected to that plug so now you know that that wire is you're hot you're gonna mark it and that wires going to go to the brass screw on your socket the other wire will go to the silver screw and it's gonna be wired properly and safe with a digital multimeter you can also measure resistance for a water heater element so the formula is volts squared divided by watts and that's going to give you resistance plus or minus two and all and all elements are marked with the watts and the volts so you can't screw up you're gonna turn off the power to the water heater you're gonna double check it with your multimeter sure the power is off once you've confirmed the powers off you can take off the cover remove the wires to the elements and now you're going to touch the two screw terminals you're going to turn it to the Omega symbol and let's say for example your element is 240 volts and 5500 watts so it's a volt squared so you're gonna go 240 times 240 which is 57600 you're going to divide it by your watts which is 5500 and you're gonna get ten point four seven so when you touch the two probes on the screw terminals of your element if it's to higher or to less than ten point four seven you know that your element is good if it's outside that range you need to change the element so it's a very easy way to test the element you know what makes a great podcast is listening to you do math the best spelling if you have a three slot outlet you can just test if there's power to the circuit by putting a red probe on the narrow slot the black probe in the wide slot and that's gonna tell you whether it's power there you can test if it's grounded by putting the red probe in the narrow slot and the black probe to the ground hole you can also test for reverse polarity putting the red probe in the wide slot and then the black probe to the ground hole and if you get power there you know that it's wired backwards there are like instructions with this I don't know whether they do a lot of tests in the instructions with a multimeter I think it's amazing I'm a multimeter listen to the fix at home improvement podcast weekly so when you're testing outlets you could have a switched outlet where half is on all the time and half is connected to a switch and if you're just checking one side the power could be off on that side from the switch but the other side is live so it could be a shock and when you remove it yeah some top-rated outlet testers Sperry Klein and amp probe non-contact electrical testers Gardner bender Sperry amp probe Klein and Milwaukee and Greenlee it's GRE en la e they have a dual tip non-contact Electrical tester and by pushing those two tips into a tamper-resistant outlet it's going to open up the shutters so you can use it just like a regular non-contact tester but it's got that unique head on it so it'll open up a tamper-resistant outlet what do you do if you don't have that sometimes it's hard if you have a non-contact electrical test or that's not real sensitive sometimes it's hard to tell whether the outlet is power so you actually have to take off the cover and then you're able to tell but with this greenly you can just push it right into the shutters and you'll know right away with multimeters Fluke FL uke and probe it's a MPR obe anova I and OVA Kline ex tech ext e CH and Gardner bender do you have anything else to add make sure you're always turning off the power to any circuits you're working on even a small shock under the right conditions could be deadly if you have an outlet tester a non-contact Electrical tester and a multimeter you're going to be able to do all the basic electrical projects around your house and if you shop around you can get these pretty cheap ok let's wrap this up you can subscribe to our podcast on Apple podcast stitcher the Spotify mobile app if Google Play Music app I Heart Radio and cash box if you enjoy this review you can check out our home improvement videos on our YouTube channel fix it home improvement subscribe to that as well you can download our books home improvement solutions what every homeowner should know on Amazon you can email us at fix it podcast at gmail.com you can follow Cindy on Twitter

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