DIY generator winding repair

In detail: DIY repair of the generator winding from a real master for the site my.housecope.com.

I have already talked about the device of electric current generators, which are arranged similarly to synchronous motors, only differ from them in the collector, therefore the process of troubleshooting and repairing electric current generators is in many ways similar to them.

In this article I will tell you in detail using the example of a do-it-yourself repair of an automobile generator, because it is it that most people most often encounter with repair. The principle of repairing a generator with your own hands as part of a power plant will be similar. Only a voltage rectifier will not be built into its case and the output voltage regulation will work differently.

Cars use a three-phase generator alternating current, but as is known in the on-board network, a constant voltage of 12 volts. To obtain direct current, a rectifier consisting of 6 diodes is used, and a voltage regulator is provided to keep the voltage of 12 volts within acceptable limits.

The generator is arranged quite simply. Voltage is applied to the rotor through graphite brushes and slip rings to excite it. It is driven by a pulley through a belt drive. The rotor rotates in bearings. Electric voltage is generated in the stator windings and converted into a constant voltage using six power semiconductor diodes, three of which are connected to the positive terminal of the generator, and the other three to the negative terminal and "vehicle ground".

If on the dashboard of the car after starting it does not go out control lamp, this indicates that the generator does not work and does not give current. But sometimes the cause of the alarm can be poor contact of the connector, wires, or a malfunction of the relay.
Battery discharge. But keep in mind that sometimes the battery is discharged and does not have time to be charged by a working generator when moving over short distances and with the light and electrical devices of the car turned on as much as possible.
Generator at engine speed 2000-2500 gives a voltage below the permissible limit of 13.2 Volts.
If the generator generates a voltage above the permissible limit of 14-14.8 Volts (depending on the model), this indicates a faulty voltage regulator, which leads to a disastrous overcharge for the battery.

Video (click to play).

Before removing the generator for repair, check:

Tensioning the drive belt and rotating the pulley, tightening its nut.
Connection to the car body of the battery and generator.
The integrity of the fuses.
Bearing play. It is checked in the same way as for electric motors according to this instruction.

Before removing and disassembling power unit, if there is generator noise during operation, try disconnecting the wires. If the noise has disappeared, then this indicates a short circuit or interturn short circuit of the stator windings or a short circuit to ground. Repair is not advisable, replacing the generator with a new one will be cheaper. If the noise persists, this indicates bearing wear. They need to be replaced.
Most often worn brushes are the cause of the malfunction... Check and replace them.
Poor contact between brushes and slip rings. Check if the spring is not pressing well. It can be stretched or replaced if necessary. Inspect slip rings for scorching or dirt. Use the finest sandpaper for cleaning and a rag for dirt. If the slip ring is severely worn, the rotor must be replaced.
Damage to the rotor winding can be checked with a multimeter. The windings should ring among themselves for a short circuit or show a small resistance. If the windings are intact, then it is necessary to ring for the lack of electrical connection between them and the case. A defective rotor cannot be repaired and must be replaced.
Damage to the stator winding are checked in the same way. The multimeter should show a short circuit or very small resistance between the terminals. And there should be no electrical contact between the winding and the generator case. The defective stator must be replaced.
Check all diodes in the rectifier. They must conduct electric current only in one direction, in the opposite direction (we swap the positive and negative probes) - the resistance is large enough. In the example in the picture, it is necessary to check each diode between points numbered 1 and number 2.

Recommend additionally will get acquainted with the instructions for repairing synchronous electric motors with their own hands, because they carry out troubleshooting in almost the same way as for generators.

Hello dear motorists! Today I will tell you how to repair a generator with your own hands. You may have already encountered such a problem, when the battery discharge indicator suddenly came on on the dashboard, this means that your car has lost its charging, and you will not have long to drive, the battery will last for a maximum of 1-2 hours.

Do not rush to throw away the generator. Try to repair it first. The most common generator malfunction is brush wear.

To check the brush assembly, you need to remove the rear plastic cover by bending the three plastic clips located in a circle.

Remove the cover, unscrew the two screws and remove the voltage regulator.

Check the wear of the brushes, if the residual length of the brushes is less than five millimeters, feel free to buy a new voltage regulator in the store. Sometimes it happens that the generator does not charge or recharges the battery, this is also a malfunction of the voltage regulator. The normal voltage of the generator is 13.5 to 14.5 volts, depending on the engine speed and the load on the generator.

The next generator malfunction is a breakdown of the diode bridge. To test the diodes, the diode bridge must be removed. We unscrew the bolts that hold the diode bridge.

Bend the wires to the side.

Remove the diode bridge. How to check a diode bridge. Read here: How to check a diode bridge?

After removing the diode bridge, be sure to check the stator windings. We do this, turn on the multimeter in dial mode and check all three stator windings for an open. All windings must ring among themselves.

Next, we check the short to ground. We connect one probe of the multimeter to ground, and the second is alternately connected to the terminals of the windings. There should be no short circuit to ground.

Similarly, we check the armature winding.

We check the anchor, there is no short circuit to ground.

Now I will show you how to disassemble the alternator to replace the bearings. We unscrew the four screws connecting the two halves of the generator together.

Unscrew the nut and remove the pulley.

Using a screwdriver, carefully split the generator in two so as not to damage the aluminum covers.

Replace defective bearings with new ones. Reassemble the generator in reverse order.

Friends, I wish you good luck! See you in new articles!

Gasoline generators, even if they are made in China, very reliable with proper care... Nevertheless, during their operation, small problems can arise that can usually be quickly fixed with your own hands. Serious breakdowns with the knowledge of the owner of the device and the principle of operation of the generator will also not be able to disable it for a long time.

If you arrange possible malfunctions of the gas generator in a kind of rating, you get the following list:

Failure or contamination of the spark plug: difficult or impossible starting, unstable operation.
Clogged carburetor: difficult starting, excessive fuel consumption, unstable operation under constant load.
Failure of the ignition coil: no spark, inability to start.
Starter breakdowns: breakage, biting of the cable, destruction of the ratchet.
Violation of valve clearances: difficult starting, increased noise during operation.
Wear of brushes (on synchronous generators) - lack of output voltage.
Speed governor malfunction: floating engine speed, dips when changing the load.
Wear of the bearings of the crankshaft and the rotor of the generator - an increase in operating noise, oil leakage.
Wear of the cylinder, piston rings - difficult starting of a cold engine, excessive oil consumption.

It does not take into account breakdowns that result from a gross violation of the rules for operating the generator: for example, seizures on the crankshaft neck due to insufficient oil level, burnout of the generator windings or voltage converter (on inverter gas generators) with frequent overloads.

In fact, malfunctions of a gasoline generator can be divided into three groups: mechanical, electrical and fuel / ignition system malfunctions.

Difficulty starting the generator, which manifested itself suddenly and not accompanied by an increase in engine noise, is a clear sign of either deviations in the operation of the carburetor (too lean or rich mixture), or a faulty ignition system (weak or intermittent spark formation). Since the diagnostics of the state of these systems is interconnected, it is combined into one section.

Remove the spark plug and inspect the carbon deposits on the electrodes.

Dense and dry black carbon deposits - a sign of a rich mixture (the carburetor is faulty, the air filter is clogged);
Oily black carbon - a sign of severe wear of the piston rings, oil enters the combustion chamber;
White soot - a sign of running on a lean mixture, it is necessary to check the carburetor.
Brick brown carbon deposits - normal for carburetor engines.
Red, green-red carbon deposits - a consequence of working on low-quality fuel.

It is simple to check the performance of the ignition system itself because of its extreme simplicity: turn on the ignition, insert a known good spark plug into the plug cap and, putting it on the nearest metal part of the engine with its skirt, turn the recoil starter abruptly. If there is no spark, disconnect the ignition switch and the oil level sensor from the ignition coil in turn: if, when both elements are disconnected, there is still no spark, replace the ignition coil.

If the spark is present and strong enough (white or blue-white), remove the spark plug after several starting attempts. A candle filled with gasoline is a sign of an over-enrichment of the mixture, a dry one is a lack of fuel.

Sometimes, after long storage, the needle and the carburetor float stick and prevent gasoline from flowing inside. Several times sharply, but do not hit the float chamber lid very hard and start again.

The most common carburetor malfunction is contamination. The ingress of dirt into the air channels leads to an over-enrichment of the mixture, into the fuel jets - to a depletion. Dirt on the float shut-off needle leads to loss of tightness and overfilling of the float chamber, which will be immediately noticeable by the leakage of fuel from the carburetor.

Let's take a look at the carburetor maintenance on the example of a Honda GX engine - its design is typical for a gasoline generator.

Remove the float chamber cover (4). Wash it in gasoline or a carburetor spray cleaner - dirt and deposits accumulate on the bottom.
Proceed in the same way with the gas valve sump (22).
Check if the gas valve is blown in the "open" position.
Take out the float shaft (3), take out the float and the shut-off needle (2). Blow out the channel with air.
Blow out the fuel jet (25), emulsion tube (11) and all carburetor passages with an aerosol cleaner or compressed air.
Remove the adjusting screw (5), blow out its channel. Then screw it in until it stops and loosen, depending on the type of air filter, by 2 (foam, paper filters) - 2.5 turns (cyclone filters).
Assemble the carburetor.

The electrical system of gas generators is quite reliable. Most often, you can face two problems: lack of battery charging on generators with electric start or lack of voltage at the generator output.

The lack of battery charging is a consequence of the failure of the rectifier or low-voltage winding. It is easy to check this system with your own hands: connect a 12-volt light bulb in parallel with the low-voltage winding of the generator and start it. A lit light means that the generator itself is working properly, and it is necessary to replace the rectifier.
The absence of voltage at the generator output is most often the result of wear on the brushes. Remove them and assess the degree of wear, replace if necessary. If your generator is an inverter type, check if the voltage comes to the input of the converter by connecting a low-power 220 V lamp in parallel with it.

Video about the phased repair of the gas generator

One of the routine maintenance provided by the instruction manual for gas generators is the control and adjustment, if necessary, of the valve mechanism clearances. An increase in clearances above the norm will lead to a decrease in engine power, an increase in noise during operation. The most dangerous is a decrease in the gap, since it is not audible during operation, but the pinched valves, especially the exhaust, begin to burn rapidly. As a result, the engine starts to work unstably and, when the plate is burned out, it stops starting.Valve Adjustment Procedure pretty simple:

Remove all components that interfere with the removal of the engine valve cover.

Remove the spark plug.

Remove the valve cover.

Set the crankshaft to top dead center of the compression stroke by the mark on the flywheel (if any) or by controlling the movement of the piston through the spark plug hole. Do not confuse compression TDC (both valves are closed) with TDC issue (the outlet valve closes, the inlet valve opens).

Loosen the locknuts of the adjusting screws and, using a flat feeler inserted between the rocker arm and the end of the valve, set the clearances by turning the screw. Typically, a clearance of 0.2 mm is adopted for the outlet valve, and 0.15 for the inlet valve (check in the operating instructions).

Tighten the locknuts and turn the crankshaft twice to TDC. If everything is done correctly, at the next dead center both gaps will go away, after another turn they will take the set value. Increased gaps after the first revolution are a sign that they were adjusted at TDC of the exhaust stroke.

Assemble the generator.

Manual starter malfunctions - perhaps the most common mechanical problem... Either the cable breaks, or the starter refuses to rewind it due to a broken return spring, or the ratchet does not turn the crankshaft. Image - DIY generator winding repair

Remove the starter by unscrewing the bolts around its casing. By unscrewing the screw (1), the ratchet can be removed. Check its cams (4) and return springs (5). Then carefully remove the pulley with the spring (7). Replace a broken cable or broken spring, whichever caused the repair.

When reassembling the starter, care must be taken to ensure that the spring remains in engagement with the shroud and pulley during installation. The cable must be fully wound around the pulley. With the ratchet in place, check the cable travel and how the starter returns to its original position.

Review and repair of the gas generator Einhell STE800

Sometimes it happens that the generator needs to be started urgently, and the recoil starter failed at that very moment. There are several emergency start methods if necessary.The methods listed below unsafe! Remove the starter cover. A flywheel with a cooling impeller is located under it, which is pulled to the crankshaft by a nut. To make it spin, you can:

With a rope wrapped around the flywheel, use it in the same way as a recoil starter rope. Note that if it snags on the fan blades, the rope will turn into a whip whip when starting the motor, so be careful. Stand so that the rope cannot get caught in your hands or head.

Low-power engines can also be started manually: with the ignition off, turn the crankshaft several times, turning the pulley by hand in the desired direction. In this case, the gas valve must be open, and the shutter of the starting device must be closed. After that, turning on the ignition, bring the crankshaft to the compression TDC (you will feel an increase in the effort on the flywheel), and then turn the pulley with a sharp jerk so that the spark energy is enough to ignite the mixture.

A powerful cordless drill and an extension head from the tool kit are a good replacement for a quick electric starter. Clamp the extension in the chuck, put a head of a suitable size on it and unscrew the crankshaft by the flywheel nut. True, in this way it will be possible to start only a low-power generator - for a large-volume engine, the drill torque is not enough to turn it on the compression stroke.

A number of faults, alas, are quite difficult to fix with your own hands, without sufficient qualifications: for example, a faulty inverter converter or voltage regulator can only be repaired with a good understanding of the principle of operation and circuitry of such devices. Not every owner of a gas generator will take up the engine bulkhead, although this is not as difficult as it might seem.In this case, it is worth contacting a specialized repair shop. You can find out the coordinates of workshops in your city on the Internet or in shops selling gasoline-powered tools.In large cities like many workshops, here are just a small part of them:A car generator is a unit that is used to provide electricity to all energy consumers in a car. Failure of the generator device will lead to the fact that all equipment will be powered by the battery, and this will subsequently cause its rapid discharge. When do generators need to be repaired, and what malfunctions are typical for this device? You will find the answers below.How much does the engine stall when the generator is loaded, what can be associated with current leakage problems, what should be the voltage, why the device does not work and how to repair the breakdown? Do-it-yourself repair of faults in automobile generators is a rather complicated matter, therefore, for a start, it recommends that you familiarize yourself with the main breakdowns of the device. Mechanical faults include damage to the mounting brackets, the unit housing, wear of the pulley and bearings, hold-down springs, etc. There can be many reasons for damage, but in any case, they have nothing to do with the electrical component.If the car engine does not start and you think that it is the generator that has broken down, then it will be useful for you to find out about the main signs of malfunctions in the operation of the unit:

A low battery indicator appears on the dashboard when the engine is running. The light can blink or stay on without interruption.

In case of incorrect operation of the device, when a higher load is imposed on the unit than that for which it is designed, the battery comes into operation to support the power supply of the equipment. This can cause the battery electrolyte to boil off.

The next symptom is that when you turn on the headlights, you can see how the optics began to burn more dimly.If you press the gas pedal, which will lead to an increase in the speed of the power unit, then the brightness of the optics will be restored to the required level.

The device howls, hums, or whistles. If during the operation of the unit, extraneous sounds began to appear, this indicates a malfunction in its operation, which may be different. Also, the generator gets very hot.

The car engine stalls from time to time for no apparent reason. A malfunction of this kind may indicate that there is a lack of voltage in the on-board network required to power electrical equipment. If at the same time the battery is fully charged, then most likely the reason lies precisely in the generator.

Now let's consider the possible causes of malfunctions, due to which it may be necessary to remove, disassemble and repair the generator device of the car:

Pulley damage or wear. If we are talking about serious malfunctions and significant damage to the pulley, then it will be easier to replace it. In some cases, repair and refurbishment is allowed, but it is best to change the device.
Damage or natural wear of slip rings, which can be damaged.
Malfunction of the regulator. The voltage regulator is designed to equalize the operating value in the electrical network of a car, its breakdown will lead to voltage surges in the network.
Breakdown of the diode bridge of the unit. If the diodes fail, the first symptom of a breakdown is the absence or too weak spark on the candles, and the battery capacity can also be reduced.
Closing the turns of the stator winding. Sometimes the problem can be solved by rewinding the winding, but often it is easier to simply replace it.
Bearing wear. If the bearing elements are worn out and broken, additional noise will appear in the operation of the unit.
Damage to the power supply circuit.

How to disassemble and how to repair the device? Below are some basic troubleshooting tips.

These tips are relevant if you know the main causes and symptoms of breakdowns:

Sometimes self-repair of the unit is impractical, so car owners have to change the device. We will consider the replacement procedure using the example of a Lada Kalina car.

To successfully complete the replacement, prepare the following tool:

wrenches for 8, 13 and 19, for more convenience, use ring and open-end;
ratchets with heads of the same size;
extension cord with a crank (video by AndRamons channel).

The replacement procedure should be carried out taking into account the recommendations and requirements of the manufacturer, which are indicated in the service book for operation. Before proceeding with the replacement, be sure to study the manual.

So, how to remove and replace the unit yourself:

Timely repair and maintenance of the unit are the main aspects that will increase the service life of the device.

What nuances should be considered:

An illustrative lesson with a detailed description of all aspects on the principle of the unit's operation is shown in the video below (the video was published by Mikhail Nesterov).

The main unit in the electrical network of the car is considered to be the generator. Thanks to the operation of this device, power is supplied to all energy consumers of the car, from optics and radio to auxiliary devices, such as a navigator and a recorder. One of the main elements of this mechanism is the generator stator. You can find out more about its structure, diagnostics and winding rewinding in this article.

The stator element consists of the following parts:

the windings themselves;
core or package;
terminals for connection to a rectifier.

Structurally, the stator device consists of three windings, in which three different values of alternating current are formed, such a circuit is a three-phase output. One end of each winding is connected to the body of the generating unit, and the other end is connected to a rectifier.To enhance and concentrate the magnetic field in the winding elements, the wires from each winding are routed around the core, which, in turn, must be made in the form of metallic plastic.

The winding of the stator device is located in special grooves, the number of which in most units is 36. In the groove itself, the winding is fixed with a slot wedge, which is also made of insulating material.

In the operation of the stator mechanism, two types of breakdowns can occur - this is a break in the windings or their short circuit to ground. As a result of prolonged exposure to humidity and temperature changes on the end surface of the core, insulation can peel and crack. This, in turn, can cause a short circuit and accelerated failure of the unit as a whole. Regardless of the cause, there is only one symptom of malfunction - the generating unit stops functioning normally, malfunctions appear in its operation, and the unit also cannot generate current.

How to check the mechanism for breakage? Depending on the malfunction, the stator mechanism can be checked for open or short circuit.

To diagnose a break, you need a multimeter or a control light:

Take the tester and activate it in ohmmeter mode, then connect the probes to the winding terminals. In the event that there is no break in the device, the tester should display a resistance value of about 10 ohms. If there is a break in the device, respectively, the current cannot pass to the windings, then the resistance value will tend to infinity. In this case, it is necessary to check all three conclusions.
As for diagnostics by control, in this case you will need to supply a negative charge from the battery to one of the contacts of the winding device. To do this, you need an insulated wire. A positive charge will need to be applied through the control to another contact. If the light source starts to burn, this indicates that the device is working normally, if not, then there is an open circuit in the system. The verification procedure will need to be repeated for each pin.

As for diagnostics for a short circuit, it can also be carried out using a tester or a lamp:

The negative test lead of the tester should be connected to the stator, and the multimeter should be set to ohmmeter mode. The positive probe connects to the winding contact, no matter which one. The procedure is repeated with each pin.
With regard to diagnostics by control, it is carried out in a similar way. The negative contact of the battery is connected to the output of the stator mechanism, and the positive contact is from the battery with any output. If the light starts to light up, this indicates that there is a short circuit in the mechanism, if not, then the device is working in normal mode. Diagnostics is carried out with each pin (the author of the video is the altevaa TV channel).

Stator repair consists in rewinding the windings.

How to do this procedure yourself:

As you can see, the procedure for rewinding the windings as a whole is a rather complicated and painstaking procedure; not everyone can cope with such a task. In total, its implementation will take at least four hours of free time. Moreover, if you make mistakes and find out about it only at the end, then we can assume that the time was wasted. Therefore, if you are not assiduous, then it may make sense to purchase a new stator.

How to avoid mistakes when performing this task - see the video below (the author of the video is the sypostat1 channel).

The modern car is literally packed with various electrical systems. The power supply of these systems is directly dependent on the generator, which consists of several components. The most important part of the generator is the generator stator.The operation of the generator and the power supply of the vehicle's on-board system directly depend on its state. In the event of generator breakdowns, many are in a hurry to replace it with a new one, although the generator is easy to sort out and restore almost any part of it. For example, it is quite possible to rewind the generator stator with your own hands.

Stator winding package;
Stator core or package;
Lead wires for connection.

The stator itself is made of three windings, three different current values are formed in them, this circuit is a three-phase output. The ends of each winding extend from the generator body (they are connected to it), the other end is connected to the rectifier. A core made of metal plates serves to concentrate and enhance the magnetic field in the generator.

The stator winding of a synchronous generator is located in special grooves, usually 36 such grooves. In each groove, the winding is held by a wedge. This wedge is made of insulating materials.

Before checking, you need to find out exactly which generator is installed on your car. You can find out from the manual, but the best way to find out the model and parameters of the generator is to look under the hood to find the factory label. On it you will find all the values you need. If you do not take into account the differences in generator models, then the result of the check will be inaccurate. Knowing the basics of electrical engineering, it is not difficult to identify various problems in the operation of the generator, as well as other systems of the electrical system.

All stator breakdowns can be conditionally divided into two groups:

Broken wire winding;
Shorting the wire to ground.

If the vehicle is operated in high humidity conditions or during sudden changes in temperature conditions, the insulation may crack and delaminate. This can provoke an inter-turn circuit and even failure of the entire generator, which will cause a sudden discharge of the battery, since the generator will not be able to fully charge it.

The generator stator is checked for either an open circuit or a short circuit. To check the resistance, a multimeter is used, as a last resort, you can use a control lamp.

The multimeter should be switched to ohmmeter mode, after which its probes are connected to the winding terminals. If there is no open circuit, the tester will show a resistance of 10 ohms. In the presence of a break, the resistance will show a value tending to infinity. With this result, three conclusions are checked. To obtain more accurate results of the check, it is better to check the obtained data with the passport data. You should be aware that inexpensive Chinese multimeters are not able to accurately show the removed resistance (accuracy is sometimes required up to tenths of an ohm), so you should get a good branded device.

If it is not possible to get any multimeter, but you need to check, you can use a control lamp (control). She will not show the exact resistance, but it will help to find a gap. With the help of an insulated wire, a negative charge from the battery is applied to the winding contact. A positive charge should be applied through the bulb to the other contact. If the light is on, then the break was not found and the device is functioning properly. This procedure is duplicated for all conclusions.Short circuit diagnostics are also carried out using a multimeter or a control lamp. The positive probe must be connected to any contact of the winding, and the negative one to the stator. This should be repeated with each pin. The turn-to-turn circuit is determined by a control lamp in a similar way. Ring all conclusions.Stator repair usually refers to the rewinding of the generator stator. For this procedure, you will need an impressive set of tools:

Winding machine;

Copper wire (about 8 coils may be needed);

Rammer;

Drilling machine;

Device for drying the varnished stator;

Hammer, set of screwdrivers and wrenches.

Winding the stator of an automobile generator is the repair of the stator. First you need to remove the stator itself from the generator. The old winding is scorched, but before that, a diagram of the generator stator winding must be drawn up, identical to the old three-phase or single-phase winding. When singed, the magnetic properties of the metal stator package do not deteriorate, so you don't have to worry. When the winding is completely burned, a complete cleaning of the seat should be carried out. Syntoflex insulating gaskets are cut and installed in the grooves.