How To Troubleshoot 3 Phase Motor With A MultiMeter (3 Phase Motor Test) Winding Resistance Test Ohm

hello everyone and welcome to jumbo man tech where we specialize in hvac but do everything diy and today i'm going to show you how to troubleshoot a three-phase motor thank you to everyone tuning in to jumper man tech if you find this video interesting or helpful please drop a like comment and subscribe and let's get straight into it once you have determined you have no control issues and your starting components are operating it's time to dive in a little deeper and troubleshoot the motor itself it's always important to look at the tag of your motor to understand what kind of motor you're actually dealing with here you can see this is a three-phase motor as well as a dual voltage motor this can be wired for 208 to 230 or 460 volts you also want to determine that this is wired properly before you actually move on safety is always first and when performing this test you're going to want to make sure that the power is off from here we can take off our cover plate we always want to make sure that our motor is the correct one for the application and we also want to make sure that it is wired properly for the correct voltage assuming everything is okay we can move on from here you're going to want to isolate your motor by disconnecting all the wires so we don't have any feedbacks we don't want any wires in our way so we're just going to take that and just pull it to the side so we don't get any feedbacks as you can see we can read l1 l2 and l3 this right here is l1 this right here is l2 and this right here is l3 and these are the points that we're going to be checking in this case we have three terminals to check or you might have just wires coming out regardless the principle remains the same for the most accurate reading you're going to want to use a mega meter but with today's technology it's not exactly needed today i'm going to be using a multimeter and i'll be using the fluke 902 fc hvac clamp meter we're going to be checking the resistance of this motor and we're also going to be checking for any grounds so to begin we're going to set our meter to ohms which is this lower symbol here which measures resistance and on top you could actually see we have a symbol for continuity at the same time my meter reads both with continuity we're going to get an audible sound and with the home reading we're going to get a detailed reading i'm going to put the light on with my meter so you guys can see it's going to be hard to capture everything all at once so i want to explain what i'll be doing we're going to be checking the resistance between any two of these points so let's we're going to start with l1 and l2 then we're going to check between l1 and l3 and then we're going to check between l2 and l three any combination between any two points basically you're going to be looking for the same resistance reading i have my meter set to ohms and continuity which in my case is both but with your meter most likely it's going to be separate but here you can learn both ways so the goal here is to get continuity between any two combinations of these three terminals and at the same time we're looking for the same resistance between any combination of any two of the three terminals so let's begin i'm going to start with l1 and l2 we had an audible sound which means we had continuity that's good and we had a reading of 2.4 ohms next i'm going to do between l1 and l3 we had continuity and we had an ohm reading of 2.4 ohms so far so good next combination would be l2 and l3 we had continuity and we had an ohm reading of 2.4 ohms so between any two of the three we got continuity with an audible sound that is good between any two of the three we got an ohm reading of 2.4 ohms and this motor checks out because that is exactly what we're looking for for a good motor if between any two of the three we did not have an audible sound that means we did not have continuity that means that your motor is bad if between any two of the three we got a reading of o l in ohms that means infinite resistance or open circuit and that means your motor is bad if we actually got in reading but it was in kiloohms it's basically the same thing as ol and your motor would be bad one thing you must take into account is the temperature of the motor before performing any of these tests many motors come with internal overloads that we cannot see of course because it is internal this is a safety device that if your motor overheats it's there to protect by open the windings what we're actually checking in this motor is essentially we're checking the windings we're checking the insides so let's say your motor overheated your windings would be open so you would check your readings and you might get ol or reading in kilo ohms and you might be mistaken that you have a bad motor but in reality it's just your safety device that opened up so you're going to want to make sure that motor is not burning hot to the touch or way above its rating temperature level you're going to want to give it some time make sure it's about room temperature or the area's temperature before you check the motor so you do not make that mistake next we can check this motor to see if there's any short to grounds so we're again we're going to set our meter to continuity or ohms personally i like to use an audible sound it just makes things so much easier so what we're going to do is keep one lead on any one of the terminals and then touch the casing of the motor anywhere here or even like above over here if the motor is like super dirty you might want to take like a piece of sandpaper so you get a good reading but regardless this is what you're going to be looking for you're going to put one lead on l1 and touch the casing if you have an audible sound then you're grounded no audible sound you're good next you're gonna put one lead on l2 touch the casing of your motor once again if you have an audible sound you're grounded if not you're good then you're gonna put one lead on l3 then touch the casing and if you have an audible sound then you're grounded if not then you're good next to check this for resistance what you're looking for is an ol reading you do not want a resistance reading so if you put one lead on one of your terminals touch the casing and you have ol then you're good l2 to the casing if you're reading ol you're good next terminal l3 to the casing if you're reading ol then you're good if you would read resistance from any line to the casing of your motor then you're grounded or if you had if you were using continuity once again and you checked from one leg to the casing on your motor and you heard an audible sound and you have continuity and you're grounded that's how you check another thing you want to take into account is to see if your shaft freely spins if you have a lot of resistance you're going to want to make sure to see if there's any zerg fittings around so you can grease your motor some of them have that some of them don't if it spins freely that's cool and if you can't spin this at all then your motor seized as well and it needs to be replaced and that ladies and gentlemen is how you properly check a three-phase motor if anybody found this video interesting or helpful please drop a like comment and subscribe and i'll catch you all next time [Music] you

Channel: Jumper man Tech

Views: 230,711

Keywords: 3 phase motor testing, 3 phase motor troubleshooting, 3 phase motor connection, 3 phase motor wiring, three phase motor troubleshooting, three phase motor testing, how to check 3 phase motor for short, how to check 3 phase motor with multimeter, how to ohm 3 phase motor, how to ohm out a 3 phase motor, 3 phase motor, how to troubleshoot 3 phase motor, hvac training videos, hvac troubleshooting, 3 phase induction motor, 3 phase motor insulation resistance test, resistance, ohms, diy

Id: cMACLA0TOuU

Length: 9min 25sec (565 seconds)

Published: Sun Jan 24 2021