How to check the armature of an electric motor at home?

Rotor for INTERSKOL USHM-2300M, HAMMER. Photo 220Volt

When an angle grinder fails, diagnostics are performed to identify the causes . One of them may be a breakdown of the armature (rotor) of the electric drive. check the serviceability/failure of this rotating assembly yourself . It is necessary to have in your arsenal only simple devices for testing the electrical circuit.

Device

To correctly diagnose armature faults, it is important to know the device and the principle of its operation . The main elements of the armature are a round core, consisting of a set of electrical steel plates and a winding wound into its grooves in a certain way. Two armature windings are placed in each of the grooves according to a special pattern . The first and last turns of one of the windings are in the same groove and are closed to one lamella.

Rotor for Makita angle grinder 9069 MAX. Photo 220Volt

The core is pressed onto the rotor , which rotates under the influence of forces arising in the electromagnetic field formed by the armature windings and the stator coils working in tandem with it. In grinders, the anchor is an assembly unit with a drive gear located at one end of the shaft, and a commutator unit at the opposite end.

Who is included in the register of collection agencies?

The supervision of the work of collection agencies is carried out by the FSSP - bailiffs. The register of collectors includes organizations that officially and with a license collect overdue debts.

The collection agency must comply with the requirements of Art. 13 of Law No. 230-FZ:

• The agency cannot employ employees who have previously been prosecuted. When applying for a job, the potential debt collector’s personal file is checked and a police clearance certificate is requested;
• The agency is required to have an official website and maintain it.
  Information must be publicly available and up to date. In particular, the site may publish cases of work done, information about employees, information about permits and licenses, contact numbers, address and company bank account to which payments must be made. Data on debts that the agency is developing, data on persons against whom collection is being carried out, cannot be disclosed. This is a violation of the rights of individuals;
• the company must have software, equipment and technical support that comply with the standards of Order of the Federal Bailiff Service of the Russian Federation No. 825;
• the agency must be included in the list of operators that process personal data of third parties. The procedure and standards of the presented procedure are specified in No. 152-FZ.

The collection agency must have an original name, which is not similar to the names of government agencies or other legal entities, and must be listed in the state register of the FSSP.

How collectors are controlled:

1. The heads of collection agencies check their employees for compliance with the law: absence of criminal records, methods used, complaints from debtors.
2. The FSSP periodically checks the legality of the actions of agencies and their leaders. Attention is paid to companies against which complaints have been received from citizens.
3. In addition to the FSSP, the activities of agencies are controlled by the Prosecutor's Office, Rospotrebnadzor, and Roskomnadzor. The key department is the bailiff service, but other organizations can apply measures within their competence based on written complaints from citizens. For example, Roskomnadzor will fine for disclosure or incorrect storage of personal data of borrowers, and Rospotrebnadzor will fine for violating consumer rights. If force is used or threats of its use are made, the police will deal with the claimants.

Causes of malfunctions

The causes of rotor failure may be improper operation of the power tool, which is represented by the following factors:

• the permissible time of continuous operation has been exceeded, which is one of the main reasons for the failure of household angle grinders;
• carrying out work in aggressive environments with the presence of sand, moisture, abrasive dust and other similar materials;
• work in conditions exceeding the permissible load;
• some mechanical faults affect the imbalance of the rotating rotor, which ultimately affects the normal functioning of the rotor electrical circuit;
• instability of the mains voltage while working with a power tool.

Serviceable rotor for Bosch angle grinder GWS6-100/GWS 850 MAX. Photo 220Volt

The operation of a power tool associated with the action of these factors leads to the following malfunctions :

• breakage of coil conductors;
• short circuit between turns due to burnt insulation;
• the insulation loses its properties, which can cause breakdown of the winding to the core body;
• violation of collector contacts;
• Particles of burnt insulating varnish or melted solder that get into the gaps that come into contact with the rotating rotor can cause mechanical damage to the elements of the angle grinder: cracks, chips, deep scratches.
• The collector lamellas wear out unevenly and carbon deposits form on them due to a short circuit.

This mainly happens when the grinder's commutator engine operates for a long time without a rest break. The winding insulation from heating loses its characteristics and melts, which leads to a short circuit of the turns. The contacts connecting the armature winding to the commutator lamellas can become unsoldered, the electric current is interrupted and the electric drive stops.

Who are “black” collectors?

Not all bureaus and agencies that did not receive permission in due time or lost it in the process of their work ceased to exist and left the market. Some of them continue to work, although their actions are illegal.

Debtors, under the guise of collectors, are sometimes called by microfinance organizations and left-wing call centers, often not even located in Russia, and demanded to repay their debts. Why do legal creditors turn to illegal debt collectors for their services? It’s simple - the cost of their services is lower than that of satellites included in the FSSP register.

The legislation clearly states that only those services that have a FSSP certificate have the right to communicate with defaulters. This means that “black” collectors work with citizens illegally. Every year the FSSP receives tens of thousands of complaints.

Almost all of them relate to the activities of illegal collectors who are not on the register. They usually work with debtors, going beyond the legal framework. The main reasons for complaints: humiliation, threats, rudeness from collectors, rudeness, destruction of property.

How to check the serviceability and ring the rotor of an angle grinder at home, video

At home, there are the following methods for diagnosing an anchor:

• visual inspection;
• using a multimeter;
• a light bulb and two wires connected to it;
• devices specially designed for checking the integrity of windings (short circuit indicator, armature testing device and others).

For more information about the types of diagnostics, see the information below, where there is a video.

Visual inspection

Even if you have a full arsenal of instruments for testing the armature electrical circuit, never neglect a visual inspection - the mandatory first step of the entire diagnostic process. A careful look will find signs by which a user who knows the design and principles of operation of the rotor will determine the nature of the malfunction.

Charred marks and the presence of a specific odor cause burnt insulation and ultimately damage to the winding wires. You should pay attention to crumpled or swollen coils , which may indicate the presence of breaks in a given location. solder particles on , which can cause a short circuit.

Violations in the contacts of the windings with the collector can be detected by burnt out lamellas . Damage to the collector itself is visually diagnosed - raised, worn or burnt plates.

Tester, multimeter

The device multimeter or its other name is a tester for measuring electrical parameters: current, voltage, resistance - can be used to search for breaks in winding wires or breakdowns in the core body.

In the following video, the author offers a diagnostic option from simple to complex. Using a multimeter, the stator is first tested. It is much easier to check it than the rotor. If there are no breaks on the stator and no breakdowns of the winding to the housing, then we can conclude that the armature is faulty. Next, you should diagnose it in more detail, determining the exact type of defect and determining the method of elimination. A continuity test is carried out with a multimeter in the “resistance test” mode with the minimum measurement scale set (up to 200 Ohms).

This video, like the other, shows the process of determining winding breaks, which is really quite labor-intensive, since measurements are taken between each pair of lamellas along the entire contour of the collector. In this case, on an armature that does not have breaks in the windings, all multimeter readings should not differ from each other within 0.1 Ohm. It is much easier to check the breakdown of the windings on the body by placing one probe on the core body and the other on the collector plates. The multimeter scale should not respond with any readings.

It is impossible to determine the interturn short circuit with a multimeter. Other devices are used here.

Interturn short circuit indicator

In the following video, the author tests a device for determining the interturn circuit (IMC) of his own making. The principle of its operation is based on the interaction of electromagnetic fields created by the coils of the IMZ device and the windings of the armature or stator. In the presence of an interturn short circuit, the parameters of the magnetic field of the device change, which is recorded by a light indication - the red light comes on, and if there is no short circuit, the green light lights up.

A light bulb

If you don’t have a multimeter, you can test the electrical circuit of the rotor using a 12 V light bulb. First , connect two wires to the light bulb itself. The power source is a regular battery, to the ends of which you should connect the ends of the break of one of the wires connected to the light bulb. Such an amateur “device” is used instead of a multimeter, where the ends of the wires are applied to the lamellas without touching each other. Carefully rotate the armature to monitor the brightness of the light bulb. If it is constantly on without blinking, then there are no breaks in the winding.

Breakdown of the winding to the core body is checked by connecting one of the ends to the collector and the other to the core or shaft. If the light comes on, it means there is a breakdown of the winding to the housing.

Throttle

The presence of an interturn short circuit in the rotor can be determined using a device for testing armatures. It is a transformer with one primary winding ; in fact, it is a wire wound on a ferromagnetic core. At the same time, it has a triangle cutout in it, in which the rotor under test can be stably positioned. Its winding begins to work as a secondary coil of a transformer.

In the presence of an interturn short circuit, the parameters of the rotor magnetic field have greater intensity; a metal strip placed on the surface of the core will vibrate and, when magnetized, will be attracted to the core body. The plate will move freely on the rotor core body if it has normal windings without defects.

Stage 7. Replacing the armature and reassembling the tool

The faulty anchor is either sent for rewinding or replaced with a new one. Fortunately, today you can find suitable components in online stores even for the cheapest Chinese instrument. Before installation, it is advisable to check a new or restored anchor using the algorithm described above.

If everything is normal, we put everything back together and work. When changing the motor armature, it is also recommended to install new brushes. Fortunately, they are cheap.

Repair and performance testing of commutator electric motors of washing machines.

Modern washing machines use several types of drive motors: commutator, asynchronous, and direct drum drive - they differ in operating principle and design. To ensure the operation of an asynchronous motor, a phase-shifting capacitor is required - a similar motor switching circuit is used in most older SM models.

Modern machines use a complex electronic control system to control an asynchronous motor, so checking it without a special stand (or “test” SM) causes certain difficulties. Even more problematic is the testing of direct drive motors (for example, they are used in LG DirectDrive cars). They are difficult to test separately since they are part of the tank structure. In addition, these engines also require a complex control system.

The easiest way (including at home) to check commutator motors, we will dwell on this in more detail.

In most modern SM, drive motors are connected according to the circuit shown in Fig. 1.

Rice. 1

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Scheme for switching on the commutator motor in the SM
From the figure it can be seen that the motor power supply circuit occurs along the following circuit: 220 V - control triac (controls the engine rotation speed) - reverse relay contacts (I or II) - stator winding - rotor winding - 220 V.

The stator winding in washing machines is switched using both contact groups of the command device and relays located in the electronic module.

Note.

In fact, the stator winding has two sections connected in concert. This solution makes it possible to reduce the penetration of interference (created by sparks on the collector) into the supply network - that is, a kind of noise suppression filter is obtained.

Repair, replacement, rewind

After diagnosing and determining the types of rotor faults, a decision on repair methods follows . It is possible to do the repair yourself, which will involve rewinding the armature yourself. If this option seems labor-intensive and complicated, you can follow a simplified scheme and replace the burnt out rotor with a new one that matches the model of the angle grinder. The simplest, but also expensive option is to contact a special service department .

When making a decision about repairing an anchor with your own hands, the information available in the articles “How to remove an anchor from an angle grinder”, “Replacing and repairing an angle grinder’s anchor”, “Rewinding an angle grinder’s anchor with your own hands” will help.

Protecting the rights of debtors: what to do in case of violations

If you are faced with forceful methods of collection (threats, insults, invasion of privacy), and also find that debt collectors are working illegally, file complaints with:

• FSSP.
  There they will check the legality of the actions, they can hold you accountable and cancel the certificate of inclusion in the register. The complaint is submitted via the website, by mail or in person to the FSSP department. (18.0 kb)
• Roskomnadzor. In case the collectors neglect the law on the protection of personal data.
• Central Bank. If you were not properly notified that the debt was transferred to debt collectors. Or if a bank or microfinance organization transferred (sold) the debt to collectors outside the registry.
• Ministry of Internal Affairs This is relevant if collectors cross all boundaries and act criminally. Here punishment is possible up to and including criminal liability.
• The prosecutor's office. In case other authorities are inactive or there is no expected result.

The complaint can be made in any form, the main thing is to provide as much detailed information as possible. If there is little information or the collector refuses to provide it, you can safely contact the prosecutor’s office.

Sometimes it is easier to write off loans than to pay them off. Learn everything about the bankruptcy procedure and forget about debt collectors forever. Our specialists will select the best option for you to end your credit burden.

How to identify a breakdown

If mechanical damage to the rotor (broken impeller, cracks, chips on the surface, play in bearing units, etc.) is visible to what is called the naked eye, then diagnosing the electrical part is somewhat difficult . Here, in addition to a visual inspection, it is necessary to carry out continuity testing and testing of the electrical circuit using special instruments. This type of work is described in detail in the article at the link “Checking the continuity of an angle grinder’s anchor with your own hands.”