How to check the stator winding angle grinder

Checking the armature / rotor and stator with a multimeter / tester

In the next video, a multimeter device, or as more commonly called a tester, is used as a tool for diagnosing the rotor and stator of an electric drive. It is used to measure various electrical parameters: resistance, current, voltage. To determine faults in the form of wire breakage, breakdown of the winding to the case, the “ohmmeter” mode is used, that is, a certain resistance value is set, which is comparable to that available in the tested circuit. In this case, with a limit of 200 ohms.

Breakdown of the stator to the housing is determined by applying indicator probes to its housing and one of the ends of the winding. The presence of any resistance value on the indicator indicates the presence of a defect in the form of a breakdown of the winding onto the case. When diagnosing a winding break, the indicator of the device will not show anything when combining the probes with the winding leads.

complex manipulations should be carried out when checking the rotor windings of the electric drive. A winding break can be in any connection with a separate collector lamella. Therefore, it is necessary to check the resistance between all lamellas of the collector, applying indicator probes to them one by one. In the absence of an open circuit, the resistance will have the same small value in all cases. Any deviation indicates a break. The breakdown of the winding on the case is checked with probes when they come into contact with the collector and “iron” from a set of sheets of electrical steel. The indicator scale should not react to this action.

However, it is impossible to determine the turn-to-turn circuit with a multimeter. Here, a device called the indicator of short-circuited loops (IKZ) is used. details about it in the information below.

Anchor device angle grinder

The motor armature of the angle grinder is a conductive winding and a magnetic circuit into which the rotation shaft is pressed. It has a pinion at one end and a manifold with lamellas at the other. The magnetic core consists of grooves and soft plates, varnished to isolate from each other.

In the grooves, according to a special scheme, two conductors of the armature winding are laid. Each conductor is half a turn, the ends of which are connected in pairs on lamellas. The beginning of the first turn and the end of the last are in the same groove, so they are closed on one lamella.

Custom check

The most accurate way is to check the stator with a metal ball and a step-down current transformer. The stator is connected to the terminals of the three phases from the transformer. After checking the correctness of the connection, we turn on our low-voltage circuit into the network.

We throw a ball inside the stator and observe its behavior. If it “stuck” to one of the windings, it means that an interturn short circuit has occurred on it. The ball is spinning in a circle. the stator is working properly. A rather unscientific, but effective method for detecting a turn-to-turn circuit on the stator.

How to replace an old gearbox with a new one

angle grinders differ in size, power, manufacturers, but the principle of the layout of the components is the same. The new motor armature angle grinder is selected strictly according to your tool model.

After unscrewing all the mounting bolts of the casing, housing and gearbox, remove the gearbox with the armature from the housing. Usually the gearbox and armature are rigidly attached to each other. To separate them, you need to disassemble the gearbox.
Unscrew the fastening bolts.
The rotor shaft is screwed to the gearbox housing with a nut. Unscrew it. Remove the gear.
Next comes the bearing. To remove it, sometimes it is enough to knock a wooden block on the gearbox housing. But more often than not, a sticky bearing cannot be removed without some tricks. There is a plate between the impeller and the bearing, which is screwed with two bolts to the gearbox. To get to them, break off a piece of a plastic impeller or burn two symmetrical holes with a heated nail. The second hole is needed for balancing if you are not going to change the impeller.
Unscrew both bolts, tap with a wooden block on the gearbox housing, and the armature will detach from it. This will keep the bearing on the shaft. Remove all bearings from the shaft with a puller.

Checking the indicator of short-circuited loops (IKZ)

There are anchors that do not have visible wires connected to the collector due to filling with an opaque compound or due to a bandage. Therefore, it is difficult to determine commutation on the collector relative to the slots. The indicator of short-circuited turns will help in this.

This device is small in size and easy to operate.

First check the anchor for breaks. Otherwise, the indicator will not be able to detect a short circuit. To do this, measure the resistance between two adjacent lamellas with a tester. If the resistance is at least twice the average, then there is a break. If there is no break, go to the next step.

The resistance regulator allows you to select the sensitivity of the device. It has two bulbs: red and green. Adjust the regulator so that the red light starts to light up. On the indicator body there are two sensors in the form of white dots, located at a distance of 3 centimeters from each other. Attach the indicator with the sensors to the winding. Rotate the anchor slowly. If the red light comes on, it means there is a short circuit.

How to rewind an anchor

Before disassembling the armature, write down or sketch the direction of the winding. It can be left or right. To determine it correctly, look at the end of the armature from the collector side. Put on gloves, use sharp cutters or a metal hacksaw. Remove the winding ends. The manifold needs to be cleaned, but it is not necessary to remove it. Carefully, without damaging the groove insulators, knock out the rods of the remaining parts of the winding using a hammer and a metal chisel.

Impregnation instructions (including speed controller)

After making sure that there are no problems, send the anchor to the electric oven to warm up for better epoxy flow.
After warming up, place the anchor on the table at an angle for better flow through the wires. Place a drop of resin on the forehead and slowly twist the anchor. Drip until glue appears on the opposite frontal area.
Position the anchor horizontally and drip onto both foreheads. Twist the anchor until it loses fluidity.
Leave upright until fully polymerized.

At the end of the process, lightly grind the manifold. Balance the armature with dynamic balancing and angle grinder. Now grind finally on the bearing. It is necessary to clean the grooves between the lamellas and polish the collector. Make the final check for open and short circuits.

The peculiarity of the winding for the variable speed angle grinder is that the rotor is wound with a power reserve. The current density affects the speed. The wire cross-section is overestimated, and the number of turns is underestimated.

Checking the armature / rotor and stator with a multimeter / tester

Device

The stator of the angle grinder is a fixed structure in the form of a core made of sheet electrical steel. It has grooves in which the winding is placed, twisted in a certain way, its wires are located parallel to each other, to reduce eddy currents.

408-316 Stator for BOSCH GWS6-100 / GWS6-115 HAMMER. Photo 220V

The winding is necessarily covered with an electrical insulating varnish in order to protect it from possible short circuits between the wires. In the grooves of the cores between the coils, insulation is made of electrical cardboard, glass tape and other similar materials. In the vast majority of models of the angle grinder, the stator is tightly fitted inside the housing made of high-strength plastic, which protects the entire electrical part of the angle grinder.

Causes of malfunction and characteristic symptoms

The main factors that affect stator failure are as follows:

408-105 Stator for Hitachi G18SE3 and HAMMER angle grinders. Photo 220V

Typical signs of a stator malfunction are as follows:

there is a persistent smell of burnt insulation of the winding wires;
the temperature of the body parts rises significantly Angle grinder;
the electric angle grinder hums more than under normal conditions;
the appearance of smoke is quite real;
the spindle starts to rotate more slowly, or even may stop completely;
the opposite to the previous case is possible, the other extreme. the spindle starts to spontaneously work at increased speeds, it is peddling.

How to ring a stator angle grinder

408-317 Stator for BOSCH GWS7-125 / GWS7-115 HAMMER. Photo 220V

The stator as an element of the electric drive of the angle grinder participates in the creation of an electromagnetic field in which the rotor rotates, which creates a torque on the spindle shaft. During operation, for a number of reasons, it fails. The user can independently diagnose damage and repair the stator.

Device
Causes of malfunction and characteristic symptoms
Visual inspection for malfunction
How to check the stator winding of an angle grinder at home in different ways

Checking the armature / rotor and stator with a multimeter / tester
On turn-to-turn circuit, indicator
Makita, without instruments
Multimeter. automatic: quickly and efficiently performs measurements

Makita, without instruments

In one of the Makita models in the following video, smoke emitted during operation, which is a sure sign of a burnt out rotor or stator. To determine the reasons, the author performed a complete disassembly of the angle grinder, which makes it possible to perform a good external examination of the angle grinder units suspected of malfunctioning. If there were no signs of smoke consequences on the rotor, then on the stator several places of burnt electrical insulating varnish were clearly visible.

On turn-to-turn circuit, indicator

The principle of operation of the device for determining the turn-to-turn closure is shown in the following video. The device in the tested winding induces a magnetic field. In the presence of short-circuited turns in the winding, the short-circuit current causes increased resistance to the electromagnetic field generated by the device. By adjusting the IKZ, a setting is performed, upon reaching which a light signal is triggered (the indicator lamp changes color from green to red) or a sound is heard. In addition to the main application, the author shows a way to determine the places of connection of the winding wires to the collector lamellas, in the absence of visually visible contacts.

How to check the stator winding of an angle grinder at home in different ways

There are a large number of different electrical devices with which you can diagnose the stator. However, at home, a limited number of technical means are used. Some are presented in the following videos.

Visual inspection for malfunction

The very first and easiest way to determine if the stator is faulty is to visually inspect it. For what it is necessary to get it out of the body of the power tool. Disassembly here will not present any difficulties. The main thing is to free it from all other structural elements of the angle grinder, including the rotor. This will make it possible, with appropriate good lighting, to inspect all surfaces of the stator winding. Usually, charred areas appear in the cliffs, which allows us to conclude that there is a defect. If a visual inspection failed to identify a malfunction of the stator, you should resort to using special devices.

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replacing bearings with an angle grinder

Visual inspection from outside

Troubleshooting should start with a visual inspection of the angle grinder:

Stator test (tagalog)

Carry out a general inspection of the tool.
Pay attention to the integrity of the power cord, the presence of voltage in the outlet.
Using the voltage indicator, make sure that current is flowing to the motor manifold and the start button.

How to remove the anchor

Replacing the armature begins with disassembling the angle grinder. The following steps are taken:

The brush assemblies are unscrewed with a screwdriver on both sides. The brushes are removed.

In what cases can you save the anchor and restore it yourself?

If the damage to the armature is established with guaranteed accuracy, the part must be removed from the electric motor. The motor must be disassembled with special care, after removing the brushes and disconnecting the power terminals. The rotor is removed together with the support bearings and the impeller for cooling the motor, they form a single whole with it.

If most of the wiring in the armature is damaged and the balance is disturbed as a result of overheating, it is better to replace it entirely. Increased vibration and uneven hum when the mechanism is operating indicates a balance imbalance.

Replacing the anchor yourself at home

Practice shows that if it is decided to replace the armature of an angle grinder, then it is best to change it together with the support bearings and the engine cooling impeller.

Replacement will require:

New anchor angle grinder. Must match your model. Interchange with other models. not allowed.
Screwdrivers, wrenches.
Soft brush and cloth for cleaning the mechanism.

How to anchor in place

To install a new angle grinder anchor in place, take a new part, and then reassemble the tool in the reverse order. The sequence of actions is as follows:

A fixing disc is installed on the armature shaft.
The bearing is installed by pressing.
The small gear is pushed on and secured with a retaining ring.
The armature is wound into the gearbox housing, the docking holes are aligned.
The gearbox mounting bolts are tightened.
The anchor with a gearbox is inserted into the body of the angle grinder and fixed.
The brushes are deposited in their places, closed with lids.

After completing the above steps, the angle grinder is ready for use. The anchor has been replaced.

Checking contacts with a light bulb

If there is no tester, you can get out of the situation with a simple 12 volt light bulb. The power can be any, optimally 30-40 watts. The voltage from the 12 volt battery must be applied to the plug of the angle grinder by inserting a light bulb into the break of one wire. With a working anchor, if you rotate the spindle by hand, the light should be on without changing the brightness. If the glow changes, this is a sure sign of an interturn short circuit.

If the light is off, then this may indicate the following:

The brushes may hang in the inoperative position. The retaining spring has worked.
There was a break in the supply circuit.
There was a short circuit or break in the stator winding.

There are other diagnostic methods, but they require more sophisticated equipment that is usually not used at home. An experienced foreman will identify a breakdown with a high degree of accuracy using a “punch” or the simplest transformer with a split toroidal core and one primary winding.

Do-it-yourself angle grinder check and repair

As Shakespeare said: “Nothing lasts forever under the moon.” Household appliances, alas, are no exception. It happens that even the most reliable mechanism fails. And we must be ready to face this fact without panic, with the firm conviction that there are no hopeless situations. How does an angle grinder work, what malfunctions can there be, how to check the motor armature, determine the cause of the breakdown and troubleshoot? Knowledge of the structure of the main units of the power tool will allow the master to diagnose and repair the angle grinder with his own hands.

How to ring an anchor with a multimeter?

To complete this procedure, you will need the measuring instrument itself and tools to disassemble the device. How to ring an anchor with a multimeter. instructions:

Prepare your work surface. There should be enough space to accommodate the necessary tools and parts removed from the device.
Disassemble the angle grinder and remove the anchor.
Clean the part from dirt and dust.
Using the recommendations in the presented video, you can independently ring the anchor with a multimeter.

At the initial stage of diagnostics, the value of the measuring device is set at 200 kOhm. If your multimeter does not have such a scale, then you can limit yourself to 20 kΩ. To ring the armature, one probe of the measuring device is applied to the ground, and the second is touched to each of the plates. If no indicators appear on the scale of an analog multimeter or a digital screen, most likely there is an interturn short circuit in the armature winding. You can accurately diagnose the problem using a special device that is available from professional locksmiths.

Features of checking the anchor angle grinder with a tester

The diagnostic procedure will help pinpoint the problem of the motor part. The device, which is in the arsenal of tools of many amateur electricians, will allow you to check the anchor of an angle grinder with a tester. With the help of the tester, you can check not only the armature of the angle grinder, but also the stator windings of other electric motors. In the video below, you can see one of these homemade measuring instruments in action.

When the tester is connected to the network, the indicator lights up. A red light without applying a technical device to the anchor means that the device is ready to be checked. The working active surface of the measuring device has two points of contact with the investigated one. One of them is the generator coil, the second is the coil of communication curls. When checking the armature of an angle grinder with a tester, it is necessary to substitute this surface to the groove under investigation. Make sure that the sensors do not extend beyond the armature plates on both sides at the same time.

If the electrical part is in good order or rewound, then during its check with the tester opposite each of the grooves, the indicator will light up green. If there is a malfunction in the armature of the angle grinder, in particular, a turn-to-turn circuit, a red light will be indicated on the indicator of the device in the place of its localization. Be careful in the diagnostic procedure to ensure proper surface contact when checking the angle grinder armature with a tester. Mechanical damage should not be excluded from the reasons for the failure of the angle grinder, which can be noticed visually without ringing with a multimeter. They can be both significant and small. You may notice a breakdown on inspection by taking apart the angle grinder. It is necessary to diagnose such malfunctions before checking the armature for interturn short circuit.

If you do not have experience in disassembling a power tool or preparing to work with measuring instruments for ringing the armature with a multimeter and are not sure of your own strength, you should not interfere with the design of the angle grinder. Do not experiment to avoid damaging the angle grinder. In this case, in order to find the cause of the breakdown of the power tool and check the armature of the angle grinder with a tester, it is better to contact the service center or to qualified locksmiths who specialize in equipment repair.

Checking the anchor with a tester. expert recommendations

Checking the anchor angle grinder with a tester. possible diagnostic results

Among the most common causes of equipment failure, the most common inter-turn closure of an angle grinder armature. It can be detected. called. with a tester. A multimeter is an electrical measuring device that includes the functions of an ammeter, voltmeter and ohmmeter. They can not only check the presence of a turn-to-turn circuit in the winding of the angle grinder, but also measure the resistance between the lamellas. A simpler device is a tester. By checking the armature of the angle grinder with it, you can detect malfunctions caused by a short circuit.

What problems in the operation of the device can be detected when checking the armature of an angle grinder with a tester

If you have sufficient knowledge to perform the correct disassembly of the power tool, then in some cases you will be able to diagnose the cause of the device breakdown with your own hands. Checking the angle grinder armature with a tester for turn-to-turn closure will allow you to determine further actions regarding the detection of faults or the repair of equipment. If the part is intact but the tool still does not work, seek qualified assistance. Did you check the angle grinder armature with a tester to accurately detect the cause of the equipment failure? If you have the necessary tools, you can repair equipment yourself in such cases:

If the winding is damaged in the upper visible layers, you can try to solder it. Such an anchor will last some more time. After sealing, it must be checked or ringed with a multimeter;
in case of turn-to-turn closure, winding rewinding or armature replacement is required.

Breakdown diagnostics and repairs of the angle grinder can be performed while energized. For the sake of your own safety, entrust this work to professionals.

Sources:

http://kovka-svarka.net/kuznechnoe-delo/kak-prozvonit-stator-bolgarki/
http://tehznatok.com/remont/proverka-i-remont-yakorya-bolgarki-svoimi-rukami.html
http://toolparts.com.ua/novosti/proverka-iakoria-testerom-rekomendatsii-spetsialistov

Angle Grinder angle, check, grinder, stator, winding