Three-Phase Motor Rewinding

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Elektromotors repairs three-phase electric motors of any complexity on favorable terms. We accept orders for urgent, current and major repairs of cranes, elevators, traction and other machines of all models and configurations.

A three-phase motor is an electrical machine operating from a three-phase alternating current network. Its main components are a stator with a triple winding and a rotor. Depending on the type of rotor, engines are divided into:

  • synchronous, with a wound rotor;
  • asynchronous, with a squirrel-cage rotor.

Rewinding of a three-phase electric motor is performed during major repairs. The reasons for replacing the winding in this case may be different:

  1. Deterioration in the quality of the insulating material and a decrease in its resistance over time as a result of temperature or mechanical influences.
  2. The occurrence of a turn or interturn short circuit, a short circuit to the housing.
  3. Wire breakage.

In asynchronous models, if there is a need to rewind a three-phase motor, work on replacing the windings is carried out only on the stator. In synchronous machines, both the stator and the three-phase rotor can be rewinded. The shaft-mounted commutator may also require repair.

Repair of three-phase electric motors

Active operation of the motor leads to gradual destruction of the winding insulation and the need to restore it. This is facilitated by heating, centrifugal forces (for the rotor), vibration, mechanical loads during startup (especially if the insulation has shrunk and the winding does not fit tightly in the grooves), exposure to moisture or dust trapped inside. As a result, the resistance of the insulating material decreases, which can ultimately lead to a short circuit and failure of the electrical machine. The quality of insulation is checked during routine repairs, and if it turns out to be unsatisfactory, then a decision is made to rewind the three-phase electric motor.

Rewinding a three-phase electric motor is a complex technological operation that includes a number of sequential works:

  1. Dismantling the old winding and cleaning the channels from the old insulation.
  2. Calculation of a new winding based on the parameters of the dismantled one.
  3. Preparation of the coils using special templates.
  4. Preparation of the active iron of the stator (rotor) and laying the winding.
  5. Soldering the coils in accordance with the diagram.
  6. Impregnation of the winding in a special varnish and drying

After the three-phase electric motor has been rewinded, varnish impregnation is carried out in order to ensure a high level of insulation of the conductive part. The next stages of repair are assembling the machine and testing it. The motor can be rewinded while maintaining its previous technical characteristics or specifying new ones required by the customer.

In any case, overhaul of a three-phase electric motor with rewinding of the stator or phase rotor is a cost-effective alternative to purchasing a new one. If all the work is done correctly, using copper wire and high-quality insulating materials, then the machine after repair will not be inferior in its technical and operational characteristics to new equipment.

Need repair consultation?

Contact us — we will calculate cost and completion times.

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Answers to popular questions about this service

Frequently asked questions

The repair time depends on the type: routine repair takes 1-2 days, rewinding takes 3-7 days, and overhaul takes 7-14 days. For urgent orders we work around the clock, and most jobs are completed within 1-3 days.

Yes. We provide a written warranty for all types of work: from 6 months for routine repairs up to 12 months for overhauls and rewinding. The warranty covers factory defects and errors in the repair performed.

Yes. We repair electric motors from any manufacturer — local (AIR, 4A, DAZO) and imported (ABB, Siemens, WEG, Mitsubishi and others). We use original spare parts or high-quality analogues.

Yes, an on-site visit by a diagnostic engineer is available in Tashkent and the Tashkent region. We will assess the motor's condition, perform initial diagnostics and draw up a work plan. The cost of the visit is discussed separately.

In most cases, repair costs 2-4 times less than buying a new motor of similar power. This is especially true for motors above 7.5 kW. See our article "Rewinding or a new motor" for a detailed comparison.

After the repair you receive: a certificate of completed work, a warranty card, and a post-repair test report (insulation resistance, no-load current, RPM). All documents can be handed over to your accounting department for asset registration.

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