YB2 Series 2-Pole Explosion-Proof Motor

Two-pole flameproof squirrel-cage induction motor certified to Ex d IIB T4 for Zone 1 and Zone 2 hazardous areas containing Group IIB flammable gases and vapours. Running at approximately 2900 rpm on 380 V 50 Hz, this motor is the standard specification for high-speed pumps, compressors, and fans in petrochemical, pharmaceutical, and solvent-handling facilities where ignition sources must be eliminated.

Ex d IIB T4 Certified
Zone 1 / Zone 2
Speed: ~2900 rpm (2P)
Power: 0.75 – 132 kW
Protection: IP55
Insulation: Class F
카테고리:
Ex d Flameproof
Group IIB T4
Zone 1 and Zone 2
IP55 Protection
IEC 60079-1
ISO 9001 Certified
YB2 Series 2-Pole Explosion-Proof Motor Ex d IIB T4 Korea Ever-Power
YB2 Motor IEC Mounting Methods IMB3 IMB5 IMB35

Certified Flameproof Motor for Zone 1 and Zone 2 Hazardous Areas

The YB2 is Korea Ever-Power flameproof explosion-protected three-phase induction motor, certified to IEC 60079-1 for Ex d (flameproof enclosure) protection in hazardous areas. The motor enclosure is designed and tested to contain any internal ignition without the flame or pressure wave propagating to the surrounding atmosphere. All flame paths (shaft seals, terminal box joint, endshield-to-frame joints) are machined to certified gap dimensions and surface finish tolerances that prevent ignition of the external flammable atmosphere even in the event of an internal arc or short circuit.

The Group IIB classification covers the majority of industrial flammable gases and vapours including ethylene, propane, methane, hydrogen sulphide, propylene, and most light hydrocarbon fractions. The T4 temperature class (maximum surface temperature 135 °C) is the most commonly required classification for petrochemical and pharmaceutical applications. For applications involving hydrogen or acetylene (Group IIC), contact Korea Ever-Power for the IIC variant which uses tighter flame path tolerances.

The 2-pole YB2 covers 0.75 kW to 132 kW in frame sizes 80M through 315M. All units carry IP55 protection as standard (dust-tight and water-jet resistant), Class F insulation with Class B temperature-rise limits, and CE marking. Terminal boxes are oversized relative to the Y2 series to accommodate the larger cable glands required by hazardous area wiring regulations.

View the complete explosion-proof range at the Explosion-Proof Motors page, or compare with standard motors at Three-Phase Induction Motors.

YB2 2-Pole Model Specifications — Ex d IIB T4

All models: 2-pole, ~2900 rpm, 380 V 50 Hz, IP55, Class F insulation, Ex d IIB T4, Zone 1 and Zone 2.

Model Frame kW Full-Load A rpm η % cosφ Tst/Tn Ist/In kg
YB2-80M2-2 80M 0.75 2.10 2840 73.0 0.83 2.2 6.5 22
YB2-90S-2 90S 1.1 2.96 2850 75.5 0.84 2.2 6.5 30
YB2-90L-2 90L 1.5 3.92 2855 77.5 0.84 2.2 7.0 38
YB2-100L-2 100L 2.2 5.50 2870 79.5 0.85 2.2 7.0 50
YB2-112M-2 112M 4.0 9.50 2880 83.0 0.85 2.2 7.0 72
YB2-132S-2 132S 5.5 12.70 2885 85.0 0.86 2.2 7.0 92
YB2-132M-2 132M 7.5 16.90 2890 86.5 0.87 2.2 7.0 116
YB2-160M-2 160M 11 23.80 2895 87.5 0.88 2.0 7.0 160
YB2-160L-2 160L 15 31.80 2900 88.5 0.88 2.0 7.0 195
YB2-180M-2 180M 18.5 38.20 2930 89.5 0.89 2.0 7.0 238
YB2-200L-2 200L 22 45.00 2940 90.0 0.89 2.0 7.0 295
YB2-225M-2 225M 30 60.00 2945 91.0 0.89 2.0 7.0 378
YB2-250M-2 250M 45 88.00 2950 92.0 0.90 2.0 7.0 490
YB2-280S-2 280S 55 106.00 2950 92.5 0.90 2.0 7.0 640
YB2-315S-2 315S 90 170.00 2955 93.0 0.90 1.8 7.0 870
YB2-315M-2 315M 132 245.00 2960 93.5 0.91 1.8 7.0 1080

Operating Conditions

Ambient temperature −20 °C to +40 °C
Altitude ≤ 1000 m ASL
Supply voltage 380 V ± 5%
Frequency 50 Hz ± 1%
Mounting IMB3 / IMB5 / IMB35
Protection IP55
Insulation class Class F
Temperature rise Class B limit
Max surface temp 135 °C (T4)

Hazardous Area Certification

Protection method Ex d (flameproof)
Gas group IIB
Temperature class T4 (135 °C max)
Zone suitability Zone 1, Zone 2
Ex standard IEC 60079-1
Motor standard IEC 60034
Quality management ISO 9001
Marking CE / Ex

Typical Applications for YB2 2-Pole Explosion-Proof Motors

YB2 2-Pole Motor Petrochemical Pump Application

Petrochemical Pumps
API 610 centrifugal pumps for crude oil, naphtha, gasoline, and light hydrocarbon transfer in oil refineries and petrochemical complexes require Ex d IIB motors as the standard specification for Zone 1 pump hall areas where flammable vapour release is possible during normal operation.
YB2 2-Pole Motor Pharmaceutical Application

Pharmaceutical Solvent Handling
Ethanol, acetone, and solvent transfer pumps in pharmaceutical manufacturing plants operate in Zone 1 areas classified under ATEX or IECEx regulations. The YB2 2-pole is the standard motor for high-speed solvent pump drives where Ex d IIB T4 covers all common pharmaceutical solvents.
YB2 2-Pole Motor Hazardous Area Fan Application

Zone 1 Ventilation Fans
Forced-ventilation and fume-extraction fans in paint booths, tank farms, and chemical storage areas require Ex d motors because the fan circulates potentially flammable atmosphere across the motor. The 2-pole motor provides the high blade tip speed needed for efficient centrifugal fan operation in these duties.
Gas Compressor Auxiliaries
Lube oil pumps, seal gas booster compressors, and cooling fans on natural gas and LNG compressor trains operate in Zone 1 or Zone 2 areas and require Ex d IIB T4 motors as the primary protection method specified by most gas processing plant engineering standards.
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Fuel Handling Systems
Jet fuel, diesel, and aviation spirit transfer pumps at fuel depots and airport fuelling systems require Ex d IIB motors with T4 temperature classification to cover the specific auto-ignition temperatures of aviation fuels under maximum ambient conditions.
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Paint and Coating Lines
Spray booth fans, solvent circulation pumps, and paint mixing equipment in automotive and industrial coating facilities operate in Zone 1 spray areas and Zone 2 surrounding areas, requiring Ex d IIB T4 motors throughout the booth ventilation and fluid transfer systems.

Understanding Ex d IIB T4 Certification for the YB2 Motor

Ex d: Flameproof Enclosure

Ex d means the motor enclosure is designed to contain any internal electrical fault, arc, or ignition within the motor body without the resulting flame or pressure wave escaping to ignite the surrounding flammable atmosphere. All joints between motor parts (endshield to frame, shaft seals, terminal box cover) are machined to IEC 60079-1 certified gap length, gap width, and surface finish specifications. These dimensions are tested to ensure that hot gases from an internal explosion are cooled below the ignition temperature of the external atmosphere before they exit the enclosure.

Group IIB: Gas Classification

The IEC gas group classification system divides flammable gases by their minimum ignition energy and maximum safe gap (MESG). Group I is mining methane. Group IIA covers propane, methane, and ammonia. Group IIB covers ethylene, ethyl ether, hydrogen sulphide, propylene, and most light hydrocarbon vapours. Group IIC (the most demanding) covers hydrogen and acetylene. The YB2 IIB certification covers all Group IIA gases by upward compatibility, plus the IIB gases, making it suitable for the majority of petrochemical and pharmaceutical hazardous area applications. Where hydrogen or acetylene is specifically present, an IIC-certified motor is required.

T4: Surface Temperature Class

The temperature class (T1 through T6) specifies the maximum permissible surface temperature of the motor exterior under any operating condition including worst-case overload. T4 limits the maximum surface temperature to 135 °C. This covers most industrial flammable substances including ethanol (365 °C ignition temperature), acetone (465 °C), propane (470 °C), and ethylene (425 °C) with substantial margin. Substances with lower auto-ignition temperatures — such as carbon disulphide (90 °C) — require T5 or T6 rated motors. Korea Ever-Power can supply T5-rated variants on request for low-ignition-temperature applications.

Korea Ever-Power Rotor Production

Rotor Production Line
Korea Ever-Power CNC Precision Machining

Precision Flame-Path Machining
Korea Ever-Power QC Inspection

QC and Certification Inspection
Korea Ever-Power Ex Certifications

Ex and ISO Certifications

Frequently Asked Questions — YB2 Series 2-Pole Explosion-Proof Motor

What is the difference between ATEX and IECEx certification, and which does the YB2 carry?
ATEX is the European Community directive (2014/34/EU) governing equipment for potentially explosive atmospheres; IECEx is the international certification system under IEC standards. Both are based on IEC 60079 technical standards, so the technical requirements are essentially identical. Korea Ever-Power supplies the YB2 with IECEx certification as standard and ATEX (CE Ex marking) for European market requirements. Both certificates cover Ex d IIB T4 classification. For markets with specific national certification requirements (such as NEPSI for China, EAC Ex for Russia/CIS, or PESO for India), please contact Korea Ever-Power specifying the target market for the applicable certificate variant.
Can I use a standard Y2 motor in a Zone 2 area without Ex d certification?
No. Both Zone 1 and Zone 2 areas require equipment certified to an appropriate protection concept (Ex d, Ex e, Ex n, or others defined in IEC 60079-0). A standard Y2 motor without Ex marking is not permitted in either zone, regardless of how rarely flammable atmospheres are present. Zone 2 areas (where flammable atmospheres occur infrequently and briefly) may accept Ex nA (non-sparking) or Ex ec (increased safety) protection in addition to Ex d, but a certified protection method is mandatory in all cases. Using uncertified equipment in any zone is a regulatory violation in all IEC-aligned jurisdictions.
Can the YB2 motor be repaired or rewound without losing its certification?
Rewinding or repair of a certified Ex d motor must be performed by a repair facility that holds an appropriate quality management approval (typically ISO 9001 with Ex-specific scope) and uses a rewinding specification that maintains the original certified winding parameters. The flame path dimensions (joint gaps and surface finish) must not be altered during repair. After repair, the motor must be re-inspected and tested by the repair facility, and documentation of the repair and re-inspection must be retained. Rewinding by a non-approved facility invalidates the Ex certification and may void the motor insurance. Korea Ever-Power can provide the original winding specification to approved repair facilities on request.
What cable gland and conduit type is required for the YB2 terminal box?
The terminal box of the YB2 is an Ex d flameproof enclosure, so cable entries must also be flameproof. Certified Ex d cable glands (armoured or unarmoured, depending on the cable type used) must be fitted in all cable entry points. Unused entries must be closed with certified Ex d stopping plugs. Conduit entries must use certified Ex d conduit sealing fittings. The cable gland size required depends on the cable outer diameter for the specific motor power rating; Korea Ever-Power can provide recommended gland sizing for each model on request.
Is a VFD permitted with the YB2 explosion-proof motor?
Operating a certified Ex d motor from a VFD is permissible but requires careful application assessment. The additional voltage stress from PWM switching and harmonics from the VFD affect the T-class surface temperature of the motor, which must be re-verified for the specific VFD operating frequency range and motor load condition. IEC 60079-14 and IEC 60034-17 provide guidance on the assessment. Korea Ever-Power can supply the YB2 with reinforced inter-turn insulation (Class H) for VFD duty in hazardous areas and can provide the temperature assessment data needed to verify that the T4 classification is maintained across the intended operating range.
What documentation is supplied with each YB2 motor?
Each YB2 motor is supplied with: the original Ex certification certificate (IECEx or ATEX as specified at order), an instruction manual covering installation, commissioning, maintenance, and repair requirements specific to the Ex d protection concept, a dimensional drawing, a wiring diagram, and factory test record confirming dielectric withstand, insulation resistance, no-load current, and frame surface temperature measurements. These documents must be retained at the installation site and made available to the local regulatory authority on request. Copies of missing certificates can be reissued by Korea Ever-Power on request with the motor serial number.

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Specify power (kW), hazardous area zone, gas group, temperature class, and any national certification requirements. Learn about our quality standards on the About Us page.

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