How to check the fan winding with a multimeter

How to check the fan motor on 220 video review

Checking of electric motor with multimeter is one of the simple ways to detect the motor malfunction and find out the reason of breakage. Synchronous and asynchronous motors with squirrel-cage and phase-wound rotors, as well as commutator motors and DC motors can be probed with a multimeter. For the test to be correct the correct procedure must be followed. To check this safely, the motor is disconnected from the mains. The first thing to do as part of testing asynchronous machines is to check the motor windings. To assess the condition of the windings in a three-phase motor it is necessary to remove the current carrying jumpers from the terminals.

Checking the winding wires for breakage The next step is to check for wire breaks in the motor windings. For this purpose, the resistance measurement range in the multimeter is set to the lowest limit and calibrated to “0”. Then the resistance of each winding of the motor is checked with a multimeter. If the tool shows one, then the circuit resistance tends to infinity, that is, there is a break in the windings.

Checking the stator for inter-turn short circuits The next step in the motor diagnostics is to check the stator windings for short circuits between the windings. For this operation it is necessary to check each winding with a multimeter and then compare all readings. A fully functional motor will have the same resistance in all windings. If on one of winding resistance value is very different from the others, then there is an inter-turn short circuit.

Checking a collector motor In order to diagnose a collector motor, the first thing to do is to check the motor armature. The tester is set in the resistance measuring mode with the lowest limit and calibrated according to the standard scheme, then the probes are applied to

Check the armature windings on the diametrically opposite lamellae to those on which the armature windings are wound. The resistance in all windings should not differ from each other. The difference in readings indicates a break in the winding.

Next, set the multimeter to maximum measurement mode and check for short circuits of the armature windings to its housing. To do this, use one feeler gauge to touch the lamellae and the other to touch the armature body. In the absence of short circuits multimeter readings should tend to infinity. Intercircuit closing of armature winding without special device, unfortunately, it is impossible to diagnose.

Also during the diagnosis of a collector motor, you must check for a short circuit of the stator windings to ground. The principle of checking is similar to that of three-phase motors with squirrel-cage rotor.

Diagnostics of the engine cooling fan (guide for dummies)

INTRODUCTIONHello, everybody! Decided to share with everyone my epic with engine cooling fan repair.I apologize for the simplicity of the statement. I am not a mechanic, I will explain everything as I understand it myself.Recently encountered a problem with the cooling fan not turning on when the coolant temperature reaches over 100 degrees. In addition, there may be another problem. the fans do not want to turn off or turn on immediately after the ignition is turned on when the engine is cold. Similar problem.

ELECTRIC COOLING FAN OPERATING SYSTEM.The sensor of fan thermal switch (located in the bottom left corner of the radiator) when heated closes the circuit with a small current going to the overload relay. I note that this sensor breaks the “minus” going to the relay. “Plus” relay takes from the ignition switch and regulated by the fuse 9 (located in the cabin of the car on the left side of the dashboard). The sensor is most often a 3-pin. Brown wire takes a “minus” from the car body. The other two wires (striped), when the sensor contacts close on them, apply “minus” to the unloading relays. Depending on how hot the coolant is, the sensor closes the circuit going to relay 14 (first speed) or the circuit going to relay 17 (second speed). Relay 72 and temperature sensors, that are on the upper cooling system pipe (blue and gray), do not participate in control of the engine cooling fan in any way, contrary to popular belief. Relay 72 only works when the ignition is turned off in aftecooling mode (I will not touch this mode).Further, when “minus” from the sensor and “plus” from the ignition switch is received, the overload relay closes power contacts and supplies “PLUS” directly to the cooling fan. “MINUS” fan takes from the body of the car (from the spar). Power “PLUS” relay takes from the battery under the protection of a fuse for 40A (60A if the radiator has two fans), which is located behind a decorative plate on the left leg of the driver (you can hardly find it, and if you find it, you can hardly get to).Well, basically this is it. Depending on which relay will get the “minus” from the sensor, and the speed will be turned on.

POSSIBLE PROBLEMS AND SOLUTIONS.If the cooling fan starts working immediately after you turn the ignition on the cold engine, the problem in 90% of cases in the sensor thermal fan switch, located in the bottom left corner of the radiator in the direction of travel (under the thick branch pipe) Probably depressed contact in the closed position. If the fan does not work when you remove the sensor wires with the ignition on, the sensor must be replaced.2) If the fan does not turn on, it is worth starting with checking the same sensor thermal fan.As said before it is a 3 contact. Remove the sensor cap and connect pins 1-3, 1-2 in the striped wire with jumper while ignition is on (conditionally brown control pin and striped control pin). If the fan in both cases rotates (with different speed). the sensor should be replaced.3) If the fan doesn’t turn on at any speed when the switch is closed, listen to the relay. If relays are clicking, it means they work. Go to p.4 If the relays do not click, then on the relay does not arrive “plus” from the ignition switch under the control of fuse 9, which is located in the hatch on the left side of the instrument panel (change the fuse). In addition, the fuse 9 also controls the buzzer. If the buzzer does not work, the problem is definitely in the fuse.It is also possible that there is no “minus” on the sensor (clean the contact from which the brown wire comes).4) If the relay clicks when the contact on the sensor wire, but the fan does not work, then most likely the relay does not come to the power “PLUS” from the battery. To test this theory, take out the relay 14 or 17, looking for a contact 0 (power contact “PLUS” from the battery) and check with a test light. For this purpose on the switched-off ignition we connect one contact of a control light bulb to contact 0, the second contact of a control light bulb we put to any place where there is a “minus”. If the light bulb lights up, so the power “PLUS” to the relay goes. Looking for an open circuit from the unloading relay to the fan (resistors under the left side member may be faulty).If the control light does not come on, there is no power “PLUS” on the relay. Most likely the problem is with 40A fuse (or 60A if you have two cooling fans), which is on the left side of driver’s legs, behind decorative cover near left footrest. First of all you need to get to it by putting near the car a good mountain of good Russian mat. As we get there, inspect the fuse for continuity (if transparent). If it is intact. clean contacts (often burned or oxidized). If not intact. change. If it didn’t help, we are looking for breakage in the circuit up to the relay.5) If you check the power contact 0 on the relay off-loading it turned out that the power “PLUS” on the relay comes, check the circuit from the relay to the fan. To do this, take a wire and turn off ignition, give 12v from the battery directly to the power contact 7 relay. “Plus” take from the battery (if it is under the hood) or a special contact under the hood (if the battery is under the seat). “Minus” the fan has to take itself from the spar. If fan doesn’t turn, clean “minus” on a spar, try again. If it doesn’t spin again, it’s worth stripping the wires directly in front of the fan and feeding the plus and minus directly from the battery. If it works, look for open circuit from relay to the fan. If it does not spin, change the fan (you can not replace the motor, it seems it is not demountable).6) To exclude from the suspicions of not working relay, you can connect the power contacts 0 and 7 of the suspicious relay with the ignition off. If the fans still do not turn, then the relay can be removed (provided that the 40A fuse is good). The problem is that the relay may work (click), but the contacts in it get burnt and the power contact to the fan is not started. Relays are more likely to get suspected if one of the fan speeds isn’t working. To check the relay can be thrown to him on legs 5 and 6 voltage 12 V. If it does not click (power contacts do not close). the relay must be replaced. If it clicked, but one of the fan speeds still does not work when the relay is installed in place, and at the same time, if at short circuit contacts 0 and 7 fan rotates. the relay to replace (burnt power contacts in the relay relief).

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Cooler blades do not rotate properly

In the case when the fan does not pull and does not convey air well, you need to disassemble the housing in which the motor is. Sometimes the fact that the propeller does not spin, may indicate insufficient lubrication in the friction bearing installed in the motor.

To disassemble the fan proceed as follows.

  • First you need to unscrew the protective mesh (its front part) and remove it.
  • After the grid, disconnect the propeller. It can be screwed to the motor shaft with the nut with left thread. That is, to unscrew the nut, turn it clockwise, and to tighten it, turn it counterclockwise.
  • Remove the rear guard by unscrewing another nut.
  • Unscrew all fasteners securing the shroud of the unit. Sometimes there is another bolt in the crank to adjust the rotation of the housing. If it is not unscrewed, you will not be able to remove the motor cover.
  • Now, with the engine open, you should drop a few drops of machine oil (better to use spindle oil) on the bushing (indicated by the red arrow) and turn the shaft several times in different directions so that the grease is absorbed inside.
  • After this procedure, easy rotation of the shaft is resumed. Reassemble the motor housing in reverse order.
  • Turn the unit on and check the airflow.

Asynchronous Motor Repair

Two- and three-phase asynchronous power units are the most common. The order of their diagnosis is not exactly the same, so we should dwell on it in more detail.

Three-phase Motor

There are two types of faults in electrical units, regardless of their complexity: the presence of contact in the wrong place or the lack of contact.

A three-phase alternating current motor has three coils that may be connected in a delta or star configuration. There are three factors that determine the performance of this power unit:

Ground faults are usually tested with a megohmmeter, but if it is not available, you can get by with an ordinary tester by setting its maximum resistance value. megohms. No high accuracy can be said in this case, but it is possible to get an approximate reading.

Before you measure the resistance, make sure that the motor is not connected to the mains, otherwise the multimeter will be unusable. Then you need to make a calibration by setting the arrow to zero (the probes in this case should be closed). To check serviceability of the tester and correctness of adjustments, it is necessary to touch briefly one probe of other each time before measurement of value of resistance.

Place one probe to the body of the electric motor and make sure that there is contact. Then take a reading by touching the motor with the second probe. If the data is within normal limits, connect the second probe to the lead of each phase in turn. A high resistance value (500-1000 Mohm or more) indicates good insulation.

How to check the insulation of the windings is shown in this

Then make sure that all three windings are intact. You can check this by probing the ends that go into the motor terminal box. If a breakage of any winding is detected, the diagnosis should be stopped until the fault is corrected.

The next point to check is to determine if there are any shorted turns. Quite often it can be seen with a visual inspection, but if outwardly the windings look normal, then you can determine the short circuit by the unequal consumption of electric current.

Two-phase electric motor

Diagnosis of power units of this type is slightly different from the above procedure. When checking a motor, equipped with two coils and powered from the usual mains, its windings should be tested with an ohmmeter. The operating winding resistance value should be 50% lower than the starting winding resistance value.

Always measure the resistance against the housing. in the normal case it should be very high, as in the previous case. A low resistance value indicates the need to rewind the stator. Of course, to obtain accurate data such measurements are better carried out with a megohmmeter, but such a possibility at home is rarely available.

Checking of collector motors

Having understood the diagnosis of asynchronous motors, let’s move on to the question of how to test the electric motor with a multimeter, if the power unit belongs to the collector type, and what are the features of such checks.

To properly check the performance of these motors with a multimeter, proceed as follows

To check the electric motor with a multimeter for an inter-turn short circuit is not possible. For this purpose, a special apparatus is used, with which the armature is checked.

A detailed check of electric tool motors is shown in this

Checking the cooler performance of the laptop

If you experience problems with the cooling system, the first thing you should do is to check the cooler. In most cases, such problems are associated with this part. To check the serviceability of the cooler laptop you do not need special knowledge or special equipment. It can be made at home in the following ways:

If you find any problems with the cooling system, it is recommended as soon as possible to eliminate them in order to prevent overheating and subsequent failure of the components. The following methods are suitable for laptops from a variety of firms: Samsung, Acer, Asus, HP, Lenovo, so you can not worry about compatibility.

Checking with the software

SpeedFan. a special program for the test of all installed fans, allows you to quickly determine the status and performance of the device without disassembling it. Using this utility, the user has full control over the operation of the fan, and can adjust the speed of rotation at various temperatures.

  • Download, install and run the software:
  • Click on the Configure button;
  • Go to Options/Languages and choose Russian to make the interface Russian.
  • Now the utility is ready to work.

Of course you don’t have to change the language, because the SpeedFan interface is pretty clear and you can see which components have a normal temperature and which are too hot. However it is important to perform all of the above steps to make it as comfortable as possible

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After tuning properly the cooling system will work much more efficiently. Please note that the speed is set in % ratio. In this example it is 100%. You can see the speed in the column “CPU FAN”, in the picture below you can see that it is “2184 RPM”.

Failed to fix the problem?Ask a professional for help!

In the case where, you set the maximum speed of the blades, and they still do not provide the normal cooling, the reason may lie in the lack of fan power or a general malfunction in the work. In this case you may need to replace it completely.

Hardware Check

The second option, how to check the laptop cooler for performance is a hardware check by disassembling the laptop. Before you disassemble and find out if the fan is working, carefully review the instructions for disassembling your device so you don’t mess anything up. If the laptop is still under warranty do not disassemble it by yourself. It is better to take to the service center, so as not to lose the warranty. Experienced craftsmen will find and solve the problem, and you do not have to puzzle over how to check whether the cooler rotates.

If you decide to disassemble the laptop yourself, note that it is not necessary to remove the fan. It is enough to get access to the wires with which it could be connected to another device. This may help save you valuable time. To check if the cooler works, you just need a USB cable with a plug on one side and two wires and (-) on the other. Then connect the wires of the USB cable to the wires of the fan (black to black, red to red), and then connect the USB cable to another computer.

What we get? If the cooler does not spin, then the whole problem is its performance, in that case you need to repair it, if, on the contrary, it rotates without any problems, then the cause of overheating is quite different. Optionally you should replace the thermal paste on the cpu and thoroughly clean the whole cooling system. If this did not help, you will have to turn to a specialized service.

Can’t fix the problem?Consult the help of a specialist!

Now you know how to check the fan operation in two simple but effective ways. Choose the most suitable one and be sure that with their help you will find the cause of the problem.

If you have not been able to fix the problem on your own, then most likely the problem lies at a more technical level. It can be: failure of motherboard, power supply unit,

hard drive, video card, RAM, etc.д.

It is important to diagnose and repair the breakage in time to prevent the failure of other components.

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Safety Precautions

Before checking the motor, make sure that the plug and cord of the entire device are in good condition. If there is electrical current flowing into the device, the control light will be on. If all is well with the current supply, proceed to check the motor, which must first be dismantled from the housing of the unit. Perform this operation only when it is completely de-energized!

It is not superfluous to check the condition of the multimeter. Most often the batteries are depleted, which can lead to inaccurate readings.

check, winding, multimeter

electric motors. device, types

Regardless of the features of the different motors, their main structural parts do not differ much:

  • in the body of any motor is fixed stator, which is similar to a sleeve, consisting of one and several windings (as in a transformer);
  • inside the stator rotates on two bearings rotor, which is a cylinder made of electromechanical steel sheets.

Based on the principle device, the motors can be divided into 4 types:

  • Collector, which operate on a direct current. most often used in automotive electrical equipment.
  • Collector motors, running on AC power. Mostly used in handheld power tools.
  • Asynchronous single- or two-phase capacitor units. Are used in the manufacture of household appliances and operate from 220 V.
  • Asynchronous three-phase, 380 V. These are the ones that work in all industrial machines.

At home most often we have to deal with damage to single-phase motors, which are equipped with home appliances. That’s why every home handyman should know how to check a defective motor.

How to test an electric motor with a multimeter ~ AUTOTEXNIKA.RU

How to test the electric motor with a multimeter

Now we will discuss how to ring the electric motor multimeter. A screwdriver-indicator is suitable for the one who knows how to use it.

One aspect: with the help of a tester, we will evaluate the characteristics, distinguish the starting winding from the working winding by the value of the resistance (in the first case the value will be twice as high).

Screwdriver-indicator is small, comfortable, the ability to use will acquire, as required, pay 30 find the latest.

The structure of an electric motor

Variety of motors abounds. Composed of moving part. rotor. non-moving part. stator. First let’s look where the copper wire is wound. The answer options are three:

Otherwise, to ring the asynchronous motor will not be more difficult, if the collector. And vice versa. The difference is limited to the principle of action, without affecting the method of assessing the serviceability of design. To correctly ring the electric motor, stop disassembling features.

Electric motor rotor

In this and the following subheading, we teach how to wire a three-phase electric motor. If there are coils (regardless of the number) on the rotor, look at the design of the slip ring. There are at least two possible answers.

Graphite brushes

Let’s see the rotor drum, equipped with pronounced sections. Current collectors are graphite brushes. Collector motor. All sections must be tested. Coil leads are opposite opposite circle sections.

Take a tester, start alternately estimating resistance: in each case the answer (in ohms) is the same plus minus the error. If an open circuit is detected, cleaning the coil does not help. If there is no endless resistance or a short circuit, the coil is burned out. Some motors have a coil resistance close to zero.

We knew what to do in this case. Take a normal 12 volt Krona, connect the rotor coil alternately low impedance (20 ohms).

Use a tester to measure the voltage drop across the coil, an additional resistor, using the proportion, calculate the value (R1/R2 = U1/U2).

Exhaust Fan Testing With Multimeter! Exhaust Fan Testing! Fan Testing With Multimeter

Please note: the resistor is high precision (series E48 or higher), so that the calculations have a small error. It is possible to measure comparably small resistances.

Note: the current reaches 0.5 A at 7 W. Instead of battery it is better to take a computer power supply or battery.

Continuous rings

The current collector is made in the form of one or more continuous rings. Indicates eloquently: synchronous motor (number of phases according to the number of sections), or asynchronous motor with a phased rotor.

Actually, we don’t care about this, because we are going to ring the motor with the tester, we are too lazy to define the purpose of the device. See the number of rings: the number is within 1 3.

How to check ceiling fan winding with digital meter |ceiling fan ki winding check to digital meter

The latter means: the motor is three-phase. Let’s start ringing.

The windings are in star connection so that the resistance between each contact is equal. If there is on hands the equipment for creation of tension of 500 V, it is necessary to ring the electric motor by megohmmeter on the case. The standard insulation value is 20 megohms.

The windings may not be able to withstand the test. With a 12 volt motor, such actions should not be taken. The result with a fully functioning rotor is an equal resistance between the contacts.

If a short-circuit to frame is detected, check whether it is a technical solution to create a system with a deaf earthed neutral point.

It is time to mention that such system is characteristic for voltages below 1 kV. However, with resonant compensation (if a motor can be found in nature) something similar may be used. The nameplate with the marking can quickly solve the problem (neutral output to the housing).

check, winding, multimeter

Collector brushes are more often perpendicular to the surface of the drum, while the current collectors are pressed at some angle. This raises the question. where is the neutral. Does not go on the frame is not used in the circuit. Often found at voltages over 3kV. Here the neutral is isolated, currents flow through the phase, where zero (or negative) is present.

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How to Ring the Electric Motor

Three-phase asynchronous electric motor, check with a tester. In practice it is sufficient to check the electric motor and the ground fault.

How to test a collector motor with a multimeter. stator and rotor windings

Greetings, you! For a start I recommend the good Internet stores. goods and services at an affordable price: The field.

In high voltage circuits the common conductor can be grounded through an arc suppression reactor. When a short-circuit of one phase to the ground, a parallel circuit is formed between the line capacitance and the reactor inductance.

Actually, the type of impedance gave the name to the device (imaginary, reactive parts of resistance). At industrial frequency, the loop resistance is close to infinity, resulting in a breakage blocked until the arrival of the repair team.

Motor stator

After calling the motor rotor, take care of the stator. Part of a simpler design. If we have an alternator in front of us, some of the windings are excitatory, in general we should simply find the resistance of each. The windings are only single-phase starting circuits. The resistance of the coil will be greater. Suppose there are three contacts, then the distribution between them is as follows:

check, winding, multimeter
  • Common wire of both windings where zero (ground) is fed.
  • The phase input of the work coil.
  • The end of the starting winding, where the voltage of 230 volts is fed, bypassing the capacitor.

The distinction is made by the value of resistance: between the phase inputs the nominal is greater, therefore, the remaining end is the neutral wire. Next, the division is carried out as indicated above.

check, winding, multimeter

The resistance of the starting coil is the highest (the difference between the zero and this contact), the remaining ends indicate the operating winding. The active part impedance rating has been reduced, reducing heat loss.

Please note: there are also 230 volt models of electric motors where both windings are considered to be working. There is not much difference in resistance between the two (less than two times).

The motor from a floor fan. The floor fan doesn’t turn on, what to do

In hot weather, a floor fan is an indispensable device that can create coolness, in the absence of. The structure of any fan includes a large number of moving parts subject to wear.

The fan and motor are mounted on different ends of the same shaft. There is also a device that allows the rotation in different directions.

From time to time, various malfunctions occur, and then it is necessary to carry out repair of floor fans.

All fans have a typical device, so their faults are also basically the same.

Deformation of the fan blades

Happens quite often because the propeller itself is made of plastic. The blades can deform under the influence of high temperatures. As a result of deformation, the blades catch on the protective grid and a characteristic unpleasant noise occurs. Deformation is usually eliminated manually, otherwise, the blades and protection will very quickly become completely useless.

Deformation of the safety guard

Appears, as a rule, as a result of a fall of a floor fan. The guard itself is made of relatively thin metal wire and includes two parts. front and back.

The front part is very easy to remove, but the back part is a bit tricky. The propeller is removed from the motor shaft, then unscrew the large plastic nut and then remove the guard itself.

After straightening, protection is assembled in reverse order.

Swinging to the sides stops

The main cause could be a loose crank. Disassemble the housing and retighten the mounting screws if they are loose or have come loose. In addition, the turning mode can be intermittent.

To determine the cause, check the engagement of the gears and the function of the switch. If necessary, the gearbox is lubricated with a special grease. In case of heavy wear and tear, it is recommended to replace the part.

If there are no parts to replace, the fan can be used as usual, without turning on.

Breaker failure

May cause intermittent operation. To check its condition, remove the switch to determine the condition of the contacts. If necessary, the contacts should be scraped with emery paper.

The fan does not work at all

In this case, check that the motor is in good condition. If it turns out that the electric motor is defective, then the repair of floor fans, in this case, is not economically feasible.

I will not dwell on mechanical faults such as repair of the impeller, housing, swivel mechanism etc. п. To correct these failures, it is simply necessary to repair or replace the worn or broken part with a new one.

This article will address electrical repair issues with the fan not turning on or the electric motor humming, smelling foul odors, or jamming.

For consideration we will take a more complex model of the floor version. Built-in exhaust fans are structurally much simpler, due to the lack of a speed-switching unit, so it is even easier to repair them.

But the repair, taking into account the price of simple model of exhaust fan without frills is inexpedient.

In order to find the cause of the fan failure you will need to disassemble it. To do it with your own hands is quite simple and fast.First remove the protective grid, then the fan blades or impeller, which is secured with a nut. Then it is necessary to remove the second part of the protective grid and unscrew the screws of the cover.

Troubleshooting when repairing a household fan

Before proceeding to repair with your own hands it is necessary to study the circuit diagram of the device. As a rule, an asynchronous motor, consisting of eight windings (operating and starting), is installed in the floor fan. For a successful start-up it is necessary to shift the phase by 90 degrees. A capacitor is installed for this purpose.

The device begins to work after you press the power button, after which the indicator light turns on and the motor starts, the speed of which depends on the winding inclusion scheme, for which is responsible switch 3 speed with a mechanical interlock with simultaneous switching of several buttons, which can cause short circuits.

Before you start checking the motor:

  • It is necessary to immediately check the serviceability of the connection cord to the power outlet. To do this you must first disassemble the switch block, and then with observance of electrical safety measures multimeter to check the presence of 220 volts on the contacts of the light bulb.
  • Check the condition of the condenser according to these instructions.
  • Test for continuity and check that all contacts of wires and connections in the circuit are secure. Testing Instruction.
  • If a hum or noise is heard when the fan is running, then lubricate the plastic parts inside the gearbox with Lithol or Solidol through the holes provided for this purpose.
  • Check for 220 Volts at the output of the on/off switch.

Fan Motor Repair

Repair of the electric motor with your own hands is necessary to begin with lubrication of bearings, very often after that the fan begins to work normally. Motor shaft rotates in plastic bushings.

Machine oil is good for lubrication. drop a couple of drops of oil into the shaft at a slant so that it runs into the inside of the sleeve, then rotate the shaft back and forth on the axis until it starts to turn easily.

The probability of motor rotor breakage is relatively small and in my practice of household equipment repair has not yet met, because an EMF (current) is induced in the rotor under the influence of stator windings.

Often in the electric motors of household fans there is a breakage in one of the winding of the stator. If even one winding is broken, then the motor will not work at all. To check it you just need to sharply rotate the blades clockwise. Just take your hand away from the blades right away so you don’t get hurt.

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