YKK Series Medium-Sized High-Voltage Three-Phase Asynchronous Motor

1. Model Code Definition (GB4831 National Standard)

1. Y: Three-phase squirrel-cage asynchronous motor, basic code for high-voltage motors
2. First K: Enclosed construction with independent internal air circulation, isolating dust, moisture and corrosive gas
3. Second K: Air-to-air cooling with top-mounted air-air heat exchanger

Full definition: YKK stands for enclosed medium high-voltage three-phase squirrel-cage asynchronous motor equipped with air-air cooler.
Derivative model difference:

• YKK: Squirrel-cage rotor, direct-on-line starting for general use
• YRKK: Wound rotor with slip rings, for heavy start-up and speed regulation

2. Working Principle of Air-to-Air Cooling (Cooling Code IC611)

Two separate closed air circuits without air mixing between inside and outside:

1. Internal circuit: Built-in fan circulates hot air from stator and rotor to the top heat exchanger.
2. External circuit: External cooling fan draws ambient cold air through finned tubes to absorb heat from internal hot air.
3. Fully sealed housing prevents workshop pollutants entering the motor interior.

3. Comparison with YKS Air-Water Cooled Motor

1. YKK (Air-Air Cooling IC611)
   No cooling water pipeline required, easy installation, suitable for water-shortage plants and outdoor units. Lower heat dissipation efficiency than water cooling, larger overall dimension and slightly higher noise.
   Application: Power plant fans, mine belt conveyors, outdoor water pumps, metallurgical plants without water supply.
2. YKS (Air-Water Cooling IC81W)
   Higher cooling efficiency, higher power density and lower noise, but requires complete circulating water system. Mainly used for closed workshops, compressors and coal mills.

4. Core Technical Parameters

1. Rated Voltage: 3kV, 6kV, 10kV
2. Power Range: 185kW ~ 2800kW
3. Frame Center Height: 355mm ~ 900mm
4. Protection Class: IP44, IP54, IP55
5. Insulation Class: Class F, S1 continuous full-load duty
6. Duty Cycle: S1 continuous operation for 24-hour non-stop running

5. Main Advantages

1. Air-only cooling eliminates water leakage risks and water pipeline construction, reducing maintenance cost;
2. Fully sealed housing resists dust, humidity and mild corrosive gas for harsh industrial environments;
3. Stable performance and high reliability with simple maintenance for unattended continuous operation;
4. Wide installation adaptability, available for indoor and outdoor sites regardless of water resource.

6. Model Example

Model: YKK500-6
YKK: Enclosed medium high-voltage motor with air-air cooling
500: Frame center height 500mm
6: 6-pole, synchronous speed 1000r/min

7. Product Brief for Webpage

YKK series medium high-voltage three-phase asynchronous motor adopts enclosed air-air cooling structure without cooling water. Dual air circulation ensures excellent protection and convenient installation. Widely applied to high-power fans, water pumps and conveying equipment in power, mining, metallurgy, chemical and water supply industries.