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Hazardous Area

YBX3

YBX3 Series High-Efficiency Flameproof Three-Phase Induction Motor

Flameproof enclosure for explosive gas atmospheres, in both a mining rating (Ex db I Mb) and an industrial rating (Ex db IIB T4 Gb), at IE3 efficiency.

Ex db IIB T4 GbIE30.18–315 kW
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YBX series flameproof three-phase induction motor

YBX3 is a totally enclosed, high-efficiency flameproof three-phase induction motor. Efficiency meets grade 3 of GB 18613—2020 — the entry level of the three-grade scale, with YBX4 at grade 2 and YBX5 at grade 1.

Protection is by flameproof enclosure to GB/T 3836.1-2021 and GB/T 3836.2-2021. Two ratings are built: Ex db I Mb for underground mining, and Ex db IIB T1 Gb to T4 Gb for surface industrial plant.

Wide voltage coverage — 380 V, 660 V, 1140 V and the dual combinations 380/660 V and 660/1140 V — means the same series covers both surface plant and underground distribution without a separate product line.

Core specifications

ParameterValue
Frame sizeH80 – H355 mm
Power range0.18 – 315 kW
Explosion protectionEx db I Mb (mining) · Ex db IIB T1 Gb – T4 Gb (industrial)
Efficiency classIE3 · GB 18613—2020 grade 3
Voltage380 V · 660 V · 1140 V · 380/660 V · 660/1140 V, 50 Hz
Protection degreeIP55
Thermal class155 (F), assessed to class B rise
CoolingIC411
MountingB3 / B5 / B35

Standards and certification

  • GB/T 3836.1-2021 (explosive atmospheres, general requirements)
  • GB/T 3836.2-2021 (flameproof enclosure "d")
  • JB/T 12628-2016 (mining rating, frames 63–355)
  • GB 18613—2020 grade 3

Typical applications

  • Underground mining — fans, local ventilation, hoisting winches (Ex db I Mb)
  • Surface plant in gas group IIB explosive atmospheres
  • Wellsites, tank farms and chemical process areas requiring a flameproof machine

Selection guide

YBX3 is certified to gas group IIB, which covers atmospheres up to and including ethylene. It is not rated for group IIC atmospheres such as hydrogen or acetylene. If your area classification calls for IIC, tell us before selection — the requirement changes the machine.
They are different certificates on the same series. Ex db I Mb is the underground mining rating; Ex db IIB is the surface industrial rating. Specify which applies to your site, because the certification documents differ.
They are the same flameproof construction one and two efficiency grades higher. On a continuously running drive the efficiency difference accumulates; on a standby or intermittent drive it rarely justifies the premium.
The classification standard says so itself. GB/T 32891.2—2019 notes that motors designed to IEC 60079-0 for explosive atmospheres may fall short of the higher efficiency classes, because the safety requirements pull the design the other way — a larger air gap, a reduced starting current, heavier sealing. Reaching grade 3 inside a flameproof enclosure is not the same engineering problem as reaching it in a standard one.
The product standard this series is built to dates from 2016 and follows the 2012 edition of GB 18613, which set no eight-pole efficiency grades at all — those arrived with the 2020 edition. So the eight-pole column in the standard table is incomplete, and that is a question of which edition the standard follows rather than what the machine can do: our engineering department confirms that tested eight-pole efficiency meets grade 3 of GB 18613—2020. Ask us for the tested value of the specific rating you need, in writing, rather than reading it off the standard table. Two, four and six poles from 0.75 kW upward are unaffected; those values are identical to grade 3 of the 2020 edition. Where the eight-pole figure has to be guaranteed in the contract rather than tested on the unit, specify YBX4, whose eight-pole column is complete in the standard and reaches grade 2.

FAQ

Not by default — the certification covers the machine under the conditions it was tested. LEADGO builds separate flameproof variable-frequency series for that duty: YBBP for mining and YBBPX3 for mining and industrial. Tell us the drive and the duty and we will confirm what is certified.
Certification copies for the explosion-protection marking, and the dimension drawings for your frame size, are issued on request. Tell us the area classification, gas or dust group and temperature class for your site.

Downloads

DatasheetPDF · 774 kBDownload
Installation & maintenance manualInstallation, commissioning and servicingRequest
CertificationCertificates and test reportsRequest

Certificates and test reports are issued against the specific model and rating rather than the series, so we send the ones that apply to your order. Tell us the rating and the market and we will send them.

Related products

YBX4

Flameproof, IE4 efficiency

YBX5

Flameproof, IE5 efficiency

YFBX3

Dust ignition-proof

YBBPX3

Flameproof variable frequency, mining and industrial

Technical articles on this series

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Equipment Protection Level: What Ga, Gb and Gc Mean

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Explosion-Proof Motor Selection: How to Read the Marking

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What a Flameproof Joint Does, and Why It Cannot Be Re-Machined

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Gas and Dust Subgroups: IIA, IIB, IIC and IIIA to IIIC

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Hazardous Area Classification: Who Does It and Who Carries the Risk

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Reading Three-Phase Motor Terminal Markings: U1 V1 W1 and T1 T2 T3

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Request a quote — YBX3

Tell us the rating, quantity and application and an engineer will come back with a specification, the documents for that model, and a price.

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