07 NLMK Group

The company

NLMK Group is a leading international manufacturer of high–quality steel products. The product line includes hot-rolled, cold-rolled, galvanized rolled products, rolled products with polymer coatings, electrical steel, a wide range of thick-rolled products, all types of rolled steel, as well as metal wares. NLMK Group's metal products are used in various industries from construction and mechanical engineering to power equipment and offshore wind turbines.

Their Request

The stator of the TDS-20000 synchronous motor which is used in an air compressor got out of order at NLMK production. Electrical malfunctions of the motor are always connected with the coil and could be the result of a coil break, a turn-to-turn short circuit, a coil fault to frame or a violation of the insulation quality of the winding wire. As a result, the electric motor overheats and burns out.

Our solution

After determining the coil malfunction, the specialists of REM&Coil started manufacturing a set of stator rods for the TDS-20000 engine. Also, the company manufactured some test coils which were sent to the customer for testing in the stator of their electric motor.
Structurally, each rod consists of two turns arranged in width. Each turn is made with a transposition of 540 degrees. The slot-embedded part of the insulated rod has dimensions of 32.9x66.8 mm.
The rod insulation system is made of electrical insulation and protective tapes produced by leading Russian enterprises.
The forming of the rods was carried out with the equipment especially designed for this kit. The total length of the shaped rod is more than 3200 mm, the length of the rectilinear part is 2200 mm.
During manufacturing, the quality department carried out 100% quality control at each technological stage. The final electrical tests included a test of frame insulation with constant and alternating voltage, a test of connection insulation, a test of coil insulation with pulsed voltage, measurement of the absorption coefficient, measurement of the tangent of the dielectric loss angle.

Стержни статора
Стержни статора

"Thanks to the Rem & Coil technologists we were able to repeat completely the manufacture coil of the electric motor, which allowed us to repair such a large engine in the conditions of our Electrical Repair Department. The engine was  repaired and delivered to the Customer."

Photo
Egor Grebennikov
Chief specialist of the ElRC