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Hazardous Area

YBX4

YBX4 Series High-Efficiency Flameproof Three-Phase Induction Motor

The same flameproof construction as YBX3, one efficiency grade higher — grade 2 of GB 18613—2020, corresponding to IE4.

Ex db IIB T4 GbIE40.18–315 kW
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YBX series flameproof three-phase induction motor

YBX4 is a totally enclosed, high-efficiency flameproof three-phase induction motor meeting grade 2 of GB 18613—2020 — the middle of the three-grade scale, above YBX3 at grade 3 and below YBX5 at grade 1.

Protection is by flameproof enclosure to GB/T 3836.1-2021 and GB/T 3836.2-2021, with the same two ratings as YBX3: Ex db I Mb for underground mining and Ex db IIB T1 Gb to T4 Gb for surface industrial plant.

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 classIE4 · GB 18613—2020 grade 2
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
  • GB/T 3836.2-2021 (flameproof enclosure "d")
  • JB/T 14517-2022 (mining rating, frames 63–355)
  • GB 18613—2020 grade 2

Typical applications

  • Continuously running flameproof drives where efficiency accumulates
  • Underground mining (Ex db I Mb) and surface IIB plant
  • Hazardous-area retrofits replacing older flameproof machines

Selection guide

Like YBX3, YBX4 is certified to gas group IIB. It is not rated for hydrogen, acetylene or other group IIC atmospheres.
Identical envelope and identical protection concept; the difference is efficiency grade and price. Where the motor runs continuously, the higher grade returns the premium through energy. Two things to settle before a like-for-like swap: the product standards guarantee a locked-rotor current roughly 15 to 25 per cent higher than YBX3, and a locked-rotor torque about 10 per cent lower. Those are the guaranteed envelopes rather than measured values, and our engineering department reports that the measured difference between the two series is smaller than the envelope suggests — so in practice the swap is usually uneventful. It is still a check worth doing: confirm the starter, the protection settings and whether the load still breaks away, and ask for the measured locked-rotor figures of the specific rating if the margin is tight.
This is where the gap is widest. The eight-pole column of YBX4 is complete and reaches grade 2, while YBX3 follows a product standard written before eight-pole efficiency grades existed at all. At eight poles the two series are not one grade apart — they are on different footings.

FAQ

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 · 822 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

YBX3

Flameproof induction motor

YBX5

Flameproof, IE5 efficiency

YFBX4

Dust ignition-proof, IE4 efficiency

YE4 (IE4)

Super premium efficiency

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Request a quote — YBX4

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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