The answer uses a concept which I’ve found to be very helpful in understanding electrical circuits: the idea of points in a circuit being electrically common to each other. Yes.… Based on this one measurement, we are able to determine that there is definitely a problem in the circuit somewhere on the left-hand side (from points C and H, left). It might be that some students get the right answer(s) for the wrong reasons, so it is good to explore the reasoning for each answer. basic electrical theory & troubleshooting. -Mary, CO Any receptacle that still has power when a breaker trips is located on a different circuit. A skill like this takes time and practice to develop, so be sure to spend adequate time throughout the course with your students honing it! Create one now. Some troubleshooters refer to this strategy as “divide and conquer,” because it divides the possibilities of fault location by a factor of 2 with each step. Consider each of these hypothetical faults one at a time (no multiple, simultaneous faults): Follow-up question: if we allow ourselves to consider more than one fault occurring at the same time, does the “switch failed shorted” scenario become possible? There are several strategies which may be employed to find the location of the problem in this circuit. Measures direct-on-line motor torque, RPM, mechanical power and motor efficiency. This guide describes troubleshooting techniques to identify such problems using portable field-testing instruments. Incidentally, this is not the only way to check the switch’s continuity, but it is the most direct. Electrical Problems. Test. The measurement of voltage between TB2-1 and TB2-2 proves the location of the failure: an “open” between those two points. Consider just one break at a time: This question is an important one in the students’ process of learning troubleshooting. PLAY. Enter your own company's plant, building, machine or process True Downtime Cost per Hour: PLC & Electrical Troubleshooting Note: the letters indicate “test points” along the wiring where you may probe with the circuit with your voltmeter. To “divide the circuit in half” again, measure voltage between points D and I. LCD display. Rather, it is a hard-learned fact: many students mistakenly think that because there is guaranteed to be no voltage between electrically common points in a circuit, then the absence of voltage between two points must mean those two points are electrically common to each other! One of my bulbs exploded (it was the wrong type). Emphasize the importance of inductive thinking: deriving general principles from specific instances. Try moving one of the loads to one of the other receptacles that still have power. Having nearly 0 ohms of resistance between points assures insignificant voltage drop, even for large currents. If voltage is measured between two points, those points must not be electrically common to each other. A feeder runs from one part of a building to another under the floor in two parallel sets of rigid non … Examine the following illustration of a simple battery-switch-lamp circuit, connected together using screw-terminal blocks, each connection point on each terminal block identified by a unique number: Determine whether or not voltage should be present between the following pairs of terminal block points with the switch in the ON position: Now, determine whether or not voltage should be present between the following pairs of terminal block points with the switch in the OFF position: Follow-up question: explain why there will be voltage or no voltage between each of these pairs of points for the two circuit conditions (switch on and switch off). Meterman Test Tools Europe P.O. You might want them to identify which points in this circuit are electrically common to one another (in either or both switch positions). Quite often a corroded connection is a substantial resistance of unstable value, leading to intermittent problems in the circuit. If zero voltage is measured between two points, those points must be electrically common to each other. All it means is that there is some other problem between the light bulb and the last two connections where voltage was measured (between TB1-1 and TB2-1). Using a voltmeter, a technician measures full battery voltage between the points C and H. The result of this single measurement indicates which half of the circuit there is a definite problem in. In this particular question, the single voltage measurement tells us definite things about the left-hand side of the circuit, but little about the right-hand side. 1. What does the behavior of this circuit tell us about electrical continuity? Identify what pair or pairs of terminal block points this different voltage will be measured between, what switch state (ON or OFF) it will appear in, and what this different voltage measurement will actually be relative to the battery voltage. The TSTrainer is a multi-media computer-based training module design to instruct the user in proper control trouble shooting … What would you recommend as the next voltmeter measurement to take in troubleshooting the circuit, following the same “divide in half” strategy? and how a corroded electrical connection is usually not equivalent to a complete “open” break in a circuit. Among other things, it is used to measure the voltage of a DC or AC current, to test electrical resistances or electrical components and to measure amps inside electrical circuits. Without this skill, you will waste a lot of time looking for unlikely faults, thereby wasting time. Light switches not working properly. Each of these statements follows the same logical pattern of electrical statements given at the beginning of this question: What we have here is an exercise in Aristotelian logic. CDI Electronics troubleshooting guide is listed below with tips, tricks and wiring diagrams. This updated classic now features: Checking for voltage across the light bulb terminals is a good step, but the lack of voltage does not prove the light bulb is not failed! This electrical troubleshooting training course uses electrical troubleshooting training simulator train and test troubleshooting electrical. Identifying the source of the problem requires the technician to … Electrical Troubleshooting. W Ð K Z I = R/V R= P/V I= P/V I = V/R .045 C 4.0 C 5.0 C 6.24 C Less resistance and draws more current Less resistance and draws less current More resistance and draws more current More resistance and… 5: Remove secondary energy. Below is user area to type your own notes. I recently moved into this home. In other words, the filament has failed “open.”. Be as specific as you can. The part where he says that if there is a problem, just sit with it and look at it awhile and maybe something will speak to you." Using a voltmeter, a technician measures 0 volts between the points C and H. The result of this single measurement indicates which half of the circuit there is a definite problem in. For all we know at this point, the light bulb could be failed as well as there being a failure somewhere else in the circuit. Spell. Based on this one measurement, we are able to determine that the battery is outputting full voltage, and that the circuit wiring is continuous from the negative battery terminal to point C, and from the positive battery terminal to point H. The fault is an öpen” somewhere to the right of points C and H - possibly more than one. Of course, this means the lamp will not turn on, no matter what is done with the switch. Outboard Motors Electrical Troubleshooting Guides Find just about everything you need to know regarding how to troubleshoot your outboard's electrical problems. In other words, which voltage measurement in this circuit (i.e. Cut the tape off the diode to unplug it for testing. Industrial Troubleshooting - Electrical . Match. It also proves that there are no other “open” failures in the circuit. always turn off power when working inside a control panel, or on any troubleshooting in the field - motor testing - motor controller - programmable logic controllers (plc). Although the circuit itself couldn’t be simpler, the fundamental concept of voltage as a quantity measurable only between 2 points is confusing for many. Operate the system and perform a road test if necessary. The first step and conclusion, while seemingly unnecessary, are actually good to check. Challenge question: identify which of the four measurement are unnecessary in determining the precise location of the fault in this circuit. Given this single voltage measurement, we simply cannot tell. To “divide the circuit in half” again, measure voltage between points B and G. Some troubleshooters refer to this strategy as “divide and conquer,” because it divides the possibilities of fault location by a factor of 2 with each step. Gravity. Compatible with smartphone, tablet, PC, Mac even 4kTV! Make sure you follow all of your companies safety precautions, rules and procedures while troubleshooting. Circuit troubleshooting is the highest level of thinking required of many electrical and electronics professionals: to identify faults efficiently based on a knowledge of fundamental principles and test equipment usage. Step 5 – Test and Repair. Switch #1 is able to control lamp #1, but lamp #2 never comes on no matter what is done with switch #2: Follow-up question: if we allow ourselves to consider more than one fault occurring at the same time, which of these scenarios becomes possible? within the industrial troubleshooting realm today, electrical troubleshooting also requires great computer skills. The second conclusion (“Power supply is functioning properly”) is understated. This is no esoteric exercise. A bulb blew out. The Electrical Troubleshooting online electrical training course covers use of schematic diagrams, determining sequence of operation, and use of building diagrams and single-line diagrams. Testing electrical equipment can be hazardous. 4: Disconnect primary energy. I have found that the concept of electrically common points is most helpful when students first learn to relate voltage drop with continuity (breaks or non-breaks) in a circuit. Explain why. In this case, the measurement tells us that a definite problem exists in one half of the circuit. Good troubleshooters are rare, and in my opinion that has more to do with the lack of effective technical education than it does a lack of natural ability. Only the contrapositive of a statement is guaranteed to share the same truth value as the original statement. This circuit provides an excellent opportunity to discuss the concept of “electrically common” points. It may be helpful to draw a schematic diagram (without all the terminal block points shown) as you discuss the reasoning with your students. 15) Power Quality & Motor Analyzer: Motor analysis test tool for evaluating the electrical and mechanical performance of electric motors, and troubleshooting power quality. The circuit shown here is called a “bridge rectifier,” and its purpose is to convert alternating current (from the “power-supply” unit) into direct current. I’ve used such a circuit, constructed on a piece of pegboard 2 feet by 4 feet, with metal screws acting as test points, for students to develop their troubleshooting skills in front of the class where everyone may observe and learn together. Knowing that there is voltage between these two terminals proves there is good continuity from TB2-3 to TB1-3, through the switch, and all the way back to the power supply. Discrete Semiconductor Devices and Circuits, What Is an aCOT? Based on these measurements, we are able to determine that the battery’s voltage is 12 volts, that the light bulb has good continuity, and that there is a single break in the circuit between points D and E. Challenge answer: the two “0 volt” measurements are unnecessary in determining the location of the fault in this circuit. Includes maintenance procedures for control circuits and combination starters. Be as specific as you can. 2: Notify employees. From step 2 we already know there is good continuity from TB2-1 back to the power supply as well. The following circuit has a problem. Certificate Course. There still could be multiple “opens” in this circuit. Circuit troubleshooting is the highest level of thinking required of many electrical and electronics professionals: to identify faults efficiently based on a knowledge of fundamental principles and test equipment usage. You should not measure any significant voltage between any of the test points along the upper wire (A to B, A to C, A to D, etc. A circuit like this is very easy to construct, and makes for an excellent classroom demonstration piece. For all we know, there may be faults in both halves of the circuit! Box 1186 5602 BD Eindhoven The Netherlands 1643507 B-ENG-N Rev. The free online electrical troubleshooting simulator is the free version of the electrical troubleshooting training simulator, a game app like no other. The exact nature of the problem is unknown, but there is definitely a problem of some nature in that half of the circuit. Wall switches: An electrician will test all wall switches for reversed polarity and ungrounded circuits, looking out for electrical problems. For each fault scenario it is important to ask your students why they think it is possible or not possible. It is very helpful to remove or unplug any devices that are … Yamaha Grizzly 700 Starting Problems Troubleshooting Test #6 After testing your brake light relay, the next electrical part to test is the diode, which is taped next to the battery and is distinguishable by a light blue wire and a black wire with a yellow stripe. The importance of using an electrical meter for safe wiring practices and to troubleshoot wiring problems. 3: Shut down equipment. Suppose a technician were troubleshooting the following circuit, whose light bulb refused to light up: The technician records their steps on a piece of paper divided into two columns: Observations, and Conclusions, drawing a horizontal line underneath each conclusion after it is made: Critique this technician’s troubleshooting job, noting any errors or unnecessary steps. The electrical energy contained in many circuits can be enough to injure or kill. Troubleshooting an Outlet Circuit Electrical troubleshooting for outlets is a process of elimination where components of the circuit are verified which helps to finally identify the problem and the make the necessary repairs. This question is not really a troubleshooting question per se, but the principles involved in successfully determining the presence or absence of voltage are critically important to being able to troubleshoot simple circuits using a voltmeter. STUDY. By Larry Bush. This question helps students build the skill of eliminating unlikely fault possibilities, allowing them to concentrate instead on what is more likely. This is not necessarily true, because situations exist where two points may not be electrically common, yet still have no voltage between them. bsettle. Notes to user: The electrical troubleshooting simulator is currently in [Explorer Mode], no electrical faults are present. The ultimate electrical equipment troubleshooting pocket guide. It is not enough to merely tell students what they should do in troubleshooting, or to give them easy-to-follow steps. Suppose this battery and light bulb circuit failed to work: Using a voltmeter, a technician measures full battery voltage between the points C and H. What does this single measurement indicate about the condition of the circuit? Dimmer switches that don’t adjust light properly can often be … A “virtual” troubleshooting exercise such as this one is a good way to start students thinking in the right ways to becoming effective troubleshooters. between which pair or pairs of terminal block points) will be unusual as a result of the bad connection at point #4, and approximately how much voltage should that measurement be? This corroded connection now has a high resistance instead of a low resistance as it should. The inexperienced troubleshooter may “chase the voltage” or mistake symptoms for problems – which leads to replacing the same parts repeatedly. Normally, the voltage across the switch in the OFF state will be full battery voltage, but now (with the open filament) it will be zero. Over time, corrosion has developed between the wire end and the screw terminal labeled “4” on the upper side of the top terminal block. It also means that most of the voltage measurements taken in the circuit will be the same as with a properly operating circuit. Determine if the light bulb will de-energize for each of the following breaks in the circuit. Electrical commonality is just one way that two points can have zero voltage between them, not the only way! This conclusively tells us that the problem(s) must lie between TB2-1 and TB2-3. It is a wasted step to check for voltage between TB1-3 and TB2-1. Although it covers many types of test equipment, this book emphasizes the use of digital multimeters (DMMs), the most common and versatile electrician’s diagnostic tool. The presence of voltage between TB2-1 and TB2-3 narrows the possibility of failure in the circuit quite a bit. safetyis the most important thing. Engage your students in a discussion of electrical commonality and expected voltage drops: Suppose this battery and light bulb circuit failed to work. The following circuit has a problem. Many home improvement stores use the term “electrical outlet” when referring to a receptacle. The following battery-switch-lamp circuit has a problem. electricity can kill you! Troubleshooting electrical wiring is best performed by electricians who understand the fundamentals of electricity and have experience installing home electrical circuit wiring. You can even ask the client todrive the vehicle so you can sit on the passenger side and monitorwhat is happening and make sure the problem … Designed for quick reference at any job site, the Electrician's Troubleshooting and Testing Pocket Guide enables electricians using portable meters to test, maintain, and troubleshoot all types of electrical equipment and systems. I have been having problems with some of my light fixtures. The final step documenting replacement of the wire between TB2-1 and TB2-2, while not essential, is not really wasted, either. What would be a fast and effective way of testing this switch’s continuity (ideally, without removing the switch from the circuit board)? In this battery-switch-lamp circuit, the metal filament wire inside the lamp has burned up, so that it no longer forms an electrically continuous connection. Effectively troubleshooting electrical systems is an essential skill for any technician responsible for maintenance in an industrial, commercial or utility facility. When the switch is closed, the lamp does not turn on: Identify which of these hypothetical faults could account for this problem, and which could not account for the problem. As a result, the light bulb does not energize when the switch is turned ON: Taking voltage measurements with a voltmeter, how do you think this corrosion problem will reveal itself with the switch on the ON position? An electrician is troubleshooting a faulty light circuit, where the power source and light bulb are far removed from one another: As you can see in the diagram, there are several terminal blocks (“TB”) through which electrical power is routed to the light bulb. In actuality, the presence of voltage between these two points proves that not only is the power supply functioning properly, but both wires between the power supply and terminals TB1-1 and TB2-1 have good continuity, and the connections between the wires and their respective terminals are good as well. It is commonly used to test potential electrical problems and components as well as to … Flashcards. Also includes plc troubleshooting training . ), nor between any of the test points along the lower wire (F to G, F to H, F to I, etc.). The following circuit has a problem. Between two points that are electrically common to each other, there is guaranteed to be zero voltage. You are in [Explorer Mode]Try draging the black lead to ground terminal and the red lead to fuse terminal. The contrapositive of this rule, however, is a valuable troubleshooting tool: if there is substantial voltage measured between two points in a circuit, then we know without a doubt that those two points are not electrically common to each other! Diagnose electrical problems by chasing voltage drops, instead of the old-fashioned way -- checking continuity. Electrical test equipment verifies the math behind a circuit and each piece of test equipment is designed for a specific application. An important skill in system troubleshooting is the ability to formulate probabilities for various fault scenarios. In this circuit, where would you expect to measure full battery voltage (between what pairs of test points)? Using a voltmeter, a technician measures 0 volts between the points C and H. What does this single measurement indicate about the condition of the circuit? A typical multimeter can measure AC and DC Voltages, Resistance, and Current. In other words, which of these faults are possible, and which are not possible, given the symptoms exhibited by the circuit? This eliminates several portions of the circuit as being problematic. Including Mike Allen's Physics 101 introduction to Ohm's law. The power probe electrical tester has an easy to use power test feature that can detect whether the circuit has a resistive or bad ground, or if it's a complete circuit. There may or may not be a problem on the right-hand side of the circuit, as well. I tried to replace it with the correct type but the light will not turn on. Conversely, if significant voltage is measured between points in a circuit, you can be assured that those points are not electrically common to each other. In either scenario (points in a circuit, or animals), statement 2 is the converse of statement 1, while statement 3 is the inverse and statement 4 is the contrapositive.