Orange/Blue, which reading should be just a few ohms, and reading should be the same in both directions (Orange/blue and blue/orange), is the secondary winding. They’re used in more complicated circuits and are used as hot wires to conduct current between switches and poles, therefore known as travelers. It has four wires, two on each side. I got a transformer from a CRT tv (it is NOT a flyback transformer). Coming out of the transformer on one side was a Black Red and Blue wire and on the other side was two yellows one of the yellows was going to a blue wire on the blower relay which is also pigtailed with the wires going to the thermostat i believe or might be condensor wires the other yellow was going to another red wire either going to condensor wire. So when I say doesn't read, it means that the one didn't change. There are usually four wires--two black and two more that are yellow, green or blue. Electrical Engineering Stack Exchange is a question and answer site for electronics and electrical engineering professionals, students, and enthusiasts. Do I have to say Yes to "have you ever used any other name?" Make sure you use extra caution when dealing with these - when you see a black wire, you know it is hot. One should read considerably higher than the other. I mistakenly tought that there were a time limit to edit answers, as there is to comments. But anyway, the AC generator is not necessary for wire identification, which is what the OP asked in the first place. Blue and Yellow Electrical Wires While wires in these colors carry power, they are not used in typical outlet wiring. However, all electrical wires, regardless of their function, may carry an electrical current at some point and should be treated with equal caution. UPDATE 1: If you are unsure of what any of these wires mean and what they do, it is important that you seek a qualified professional to answer any questions you may have. How come it's actually Black with the advantage here? Although neutral, these wires still may carry a current, especially an unbalanced load, so handle with caution. One winding should be in a few hundred ohms, and one just a few ohms. However, he will need at least a cheap meter, otherwise he will have to guess! Connect one of the wires (yellow or white) to the switch, and connect the other pin of the switch to another wire, and this wire to AC output. You'll kill the winding or the supply or both. The values I suggested (5V, 10kΩ / 100kΩ) are quite conservative, and are not likely to cause accidents, sparks or anything. Trying to identify a bunch of parts from sets I had as a child 20 years ago. The colors white and gray indicate a neutral wire. Measure the DC resistance of each winding, and report. Black wires are never used for a ground or neutral wire and are meant to be used as the power feed for a switch or an outlet. The ratio between this voltage and 5V will give you the voltage conversion rate of your transformer. Example of X and Z are correlated, Y and Z are correlated, but X and Y are independent. I fear that this answer will not help an OP who is trying to test a transformer using a 9v battery and watching the sparks! On the other, I think Blue/Orange are a pair and Yellow and White are aswell. rev 2020.11.24.38066, The best answers are voted up and rise to the top, Electrical Engineering Stack Exchange works best with JavaScript enabled, Start here for a quick overview of the site, Detailed answers to any questions you might have, Discuss the workings and policies of this site, Learn more about Stack Overflow the company, Learn more about hiring developers or posting ads with us. end-of-world/alien invasion of NYC story, Removing an experience because of company's fraud. Red electrical wires are the secondary live wires in 220-volt circuits and are commonly found in a sheathed, multi-conductor cable. Green wires connect to the grounding terminal in an outlet box and run to the ground bus bar in an electrical panel. White wires are typically found in residential buildings while gray ones can be found in commercial settings. Don't even try to plug a DC supply to a winding. Anyways, back to my multimeter. Just be sure it's an AC voltage about 60Hz, not DC! He probably doesn't have a multimeter neither a continuity tester, and maybe don't know what those equipments are. Calculate Azimuth from polygon in GeoPandas. @Marcovecchio, I voted +1 for this answer that talks about using three resistors and also a 5V 60Hz sinusoidal generator, because it is technically perfect, but, for a perfect world. Making statements based on opinion; back them up with references or personal experience. Center tap ----- yellow/blue Filament winding No. Next step: Connect a wire to yellow and another to white. Put the transformer on a clean and empty surface, keep some distance, and turn the switch on (but be prepared to turn the switch off immediatelly, if necessary). Now you can optionally test the voltage ratio of your transformer, if you have an AC power source: get a resistor between 10kΩ and 100kΩ and connect it to the lower resistence winding, and apply a 5V, 60Hz AC (preferably sinusoidal) voltage to the higher resistence winding. These wires are often used as a switch leg that transfers power to switches and outlets in all circuits. It only takes a minute to sign up. The higher resistence winding will work with higher voltage and less current. White wires augmented with red or black tape or markings are used as hot; however, a black wire can never be used as a neutral or ground wire, or for any purpose other than to carry a live electrical load. To subscribe to this RSS feed, copy and paste this URL into your RSS reader. k is kilo. Look for pairs of wires that read low resistence between them. If I plug 9V into the orange one, and touch the negative side to blue, it makes sparks. 3 ----- slate Center tap ----- slate/yellow I have seen primaries with other color schemes; if it includes black it should be a primary lead of some sort. White/Blue: doesn't read. @Barry Maybe the OP has a bicycle dynamo, a hamster wheel, and a suitable rodent? @mguima @Marcovecchio That comment made my day ;). Once you find the pairs (or windings), do the next check: cross check each winding to be sure the transformer is not shorted. 1 ----- green Center tap ----- green/yellow Filament winding No. If you see a white wire marked with black or red (or a piece of black or red electrical tape at its ends), that means it’s acting as a hot wire and is no longer neutral. Blue/Yellow: doesn't read, White/Orange: doesn't read Stack Exchange network consists of 176 Q&A communities including Stack Overflow, the largest, most trusted online community for developers to learn, share their knowledge, and build their careers. It's difficult to figure out which are OP quotes in you answer. These wires are typically used for switch wiring as well as the interconnection between smoke detectors hard-wired into the power system. For reference, doesn't read means that nothing changed. I have a standard transformer with 7 wires: 2 black 2 red 2 yellow 1 red/yellow striped What connections do these wires correspond to? Then, measure voltage across the resistor. On one hand, I'm spooked. @mguima, I agree! The lower resistence one will work at lower voltage and higher current. While DIY options are feasible, dealing with the electrical issues in your home can be an overwhelming task. The red and black wires were going to … This is incredibly important to know before you start any kind of home wiring project, as well as essential to your safety, so let’s explore what these colored wires mean and when to use them. If I connected the positive to white and touch the negative to the yellow wire, it does makes sparks but they are less prominent. But what does each one mean? I'm going to test the voltage ratio, then report back. Asking for help, clarification, or responding to other answers. By default, the multimeter reads "1", until I hook it up. If a person is dressed up as non-human, and is killed by someone who sincerely believes the victim was not human, who is responsible?