High Efficiency: YJS Series 6kV/400kW High Voltage Motor (IC411)

YJS‑series 400 kW 6 kV high‑voltage three‑phase squirrel‑cage asynchronous motor is a compact totally‑enclosed high‑efficiency drive unit complying with IEC standards. Featuring IC411 self‑fan cooling (TEFC‑totally enclosed fan‑cooled), this motor eliminates bulky top‑mounted air‑to‑air heat exchangers required by traditional YKK models. Its rib‑cooled cast‑iron frame delivers small footprint and light weight, making it well‑suited for installations with limited space. Designed for S1 continuous heavy‑duty operation, it can be directly connected to 6 kV power grid and is widely deployed in petrochemical, water conservancy, power, mining and building‑material industries to drive water pumps, blowers, compressors and general processing equipment.

Core Technical Parameters 

Electromagnetic performance is optimized via finite‑element simulation for compact high‑voltage constraints. The stator core adopts premium low‑loss silicon‑steel laminations to lower iron loss, stray loss and magnetic leakage under long‑time full‑load running. Stator windings use corona‑resistant high‑conductivity copper magnet wire and go through full VPI vacuum pressure impregnation treatment. The solid integrated winding structure enhances dielectric strength, thermal stability and anti‑aging capability, resisting grid voltage fluctuation and repeated startup impact. The copper‑bar squirrel‑cage rotor is standard for this 400 kW rating, offering excellent mechanical rigidity, low rotor loss and reliable starting characteristics. Each rotor assembly undergoes strict high‑precision dynamic balance calibration to keep vibration and noise within IEC‑specified limits across the full working range.

Distinctive mechanical design defines YJS series advantages. The high‑strength cast‑iron frame is equipped with densely arranged external cooling ribs. Internal heat transfers through frame ribs and is dissipated by the shaft‑driven external fan under IC411 cooling principle. Since no separate air‑to‑air heat exchanger is needed, overall motor dimension is significantly reduced compared with equivalent‑power YKK box‑type motors, saving valuable floor space inside equipment rooms. Fully‑enclosed construction prevents dust, moisture and light corrosive gas from invading windings and iron core, delivering better environmental adaptability than open‑type IP23 Y‑series motors.

Bearing configuration is selected according to pole number and rotating speed. Medium‑speed models adopt heavy‑duty rolling bearings; high‑speed variants can be equipped with sliding bearings. PT100 temperature sensors can be embedded inside stator windings and bearing housings as optional configuration, feeding real‑time temperature data to central control system for remote monitoring and over‑temperature early warning. Space heater can be fitted to avoid winding condensation during motor shutdown. For variable‑frequency working conditions, IC416 independent external fan cooling can be supplied to guarantee adequate cooling airflow at low‑speed operation. Customization covers high‑altitude adaptation, damp‑tropical anti‑corrosion coating, special terminal box layout and double‑shaft extension upon project requirements.

This 400 kW YJS motor serves broad industrial applications. In power plants, it drives auxiliary blowers and circulating water pumps; in chemical and petrochemical facilities, it matches process compressors and conveying equipment; in mining and cement sectors, it supports fans and auxiliary mills. It supports direct‑on‑line startup or high‑voltage soft‑starter configuration according to on‑site grid capacity. Before delivery, each unit completes full‑range factory acceptance tests, including insulation resistance test, high‑voltage withstand test, no‑load running test, efficiency verification, vibration and noise inspection. Featuring compact layout, high efficiency, fully‑enclosed protection and convenient maintenance, YJS‑series 6kV‑400 kW IC411 high‑voltage motor provides an economical and reliable drive choice for modern industrial projects with space‑limited installation conditions.