YB2‑500‑6 Explosion‑Proof Motor｜355kW 11kV for Steel‑Mill

The YB2‑500‑6 high‑voltage flame‑proof asynchronous motor adopts Exd II BT4 Gb explosion‑proof standard with valid explosion‑proof certificate. Rated at 355kW,11kV, IP55 protection and F‑class insulation, cooling method IC411 and S1 continuous‑duty system. Its efficiency is greatly improved compared with conventional YB series motors. It is widely applied for fans, pumps, compressors and crushers in steel‑making, petroleum, chemical, coal‑mine and other explosive‑gas‑risk sites.

This series of flameproof three-phase asynchronous motors is independently developed by our company for explosive gas environments, featuring high efficiency, safety, reliability, and compact structure. The motors are significantly more efficient than comparable products — under the same power and pole count, the YB2 series achieves an average efficiency increase of 2 percentage points over the YB 355–450 series, and 1 percentage point over the YB 560–710 series.

These motors are primarily used in explosive gas environments in industries such as petroleum, chemical, coal, power generation, metallurgy, transportation, textile, pharmaceutical, and grain processing. They are ideal for driving fans, pumps, compressors, crushers, machine tools, conveying machinery, and other general-purpose equipment — making them the perfect power solution for core equipment in flammable and explosive operating conditions.

Key Features

• High Efficiency & Energy Saving – Efficiency increases by 1–2 percentage points over previous generations at the same power and pole count, significantly reducing operating energy costs

• Flameproof Design – Certified with national flameproof approval, Ex d II T4 Gb, suitable for factory use in Zone 1 and Zone 2 explosive gas environments (II T4 group)

• High Reliability – Class F insulation, IP55 protection, suitable for high-temperature, high-dust, and humid conditions

• Low Noise Operation – Optimized electromagnetic and ventilation design keeps noise level at 98 dB(A) (1W)

• Anti-Condensation Heater Included – Built-in heater (240V/350W) prevents moisture absorption in windings during shutdown, extending motor life

• Compact Structure – Box-type welded steel plate construction with good rigidity and strength; easy installation and maintenance

• Strong Environmental Adaptability – Suitable for indoor/outdoor installation in explosive gas atmospheres

Efficiency Comparison

The YB2 series adopts advanced electromagnetic design and manufacturing processes, delivering significantly higher efficiency than previous generations at the same power and pole count — providing long-term energy savings for customers.

Typical Applications

This motor series is suitable for driving equipment in the following explosive gas environments:

Explanation of Ex d II T4 Gb:

• Ex d: Flameproof enclosure

• II: Factory-use electrical equipment (not mining)

• T4: Temperature class, max surface temperature ≤ 135°C

• Gb: EPL (Equipment Protection Level) — suitable for Zone 1 and Zone 2 explosive gas atmospheres

Operating Conditions

• Ambient Temperature: -15°C to +40°C

• Altitude: Not exceeding 1000m

• Suitable Areas: Zone 1 and Zone 2 explosive gas atmospheres (II T4 group)

• Protection Class: IP55 (dust-proof and protected against water jets)

• Cooling Method: IC 411 (Self-fan cooling)

• Mounting: Customizable upon request

• Anti-Condensation Heater: Recommended to be turned on during shutdown to prevent winding moisture

Safety & Certification

• National Flameproof Certification: CJEx13.0956

• Flameproof Marking: Ex d II T4 Gb

• Complies with national flameproof electrical product standards

• Suitable for petroleum, chemical, coal mining, and other hazardous explosive gas areas