YBK3 Series Flameproof Three-Phase Asynchronous Motors for Underground Coal Mines

1. Product Overview

The YBK3 Series Flameproof Three-Phase Asynchronous Motors for Underground Coal Mines are axially ventilated, totally enclosed, self-fan-cooled, squirrel-cage flameproof three-phase asynchronous motors. As an upgraded and replacement basic series for underground coal mine flameproof motors in China, they supersede the YBK2 Series. These motors boast advantages including high efficiency, large torque, strong overload capacity, low noise, low vibration, large temperature rise margin, excellent performance, easy installation and maintenance, long service life, reasonable flameproof structure, safe and reliable operation, and an attractive appearance.

2. Applications

Suitable for underground coal mine excavation working faces where there is a risk of methane mixture and coal dust explosion.

3. Executive Standards

GB3836.1-2010 Explosive Atmospheres - Part 1: General Requirements for Equipment

GB3836.2-2010 Explosive Atmospheres - Part 2: Equipment Protected by Flameproof Enclosures "d"

4. Basic Features

Frame Size: 100～355

Rated Power Range: 2.2～315kW

Number of Poles: 2～10 poles

Rated Voltage: 380V, 660V, 380/660V, 660/1140V

(Note: Deviations of power supply voltage and frequency from rated values during motor operation shall comply with the provisions of GB755.)

Rated Frequency: 50Hz

Insulation Class: Class F

Efficiency: IE3 (3rd Level Energy Efficiency)

Cooling Method: IC411

Mounting Type: IMB3, IMB35, IMB5

Protection Class: IP55

Duty Type: S1

Explosion-Proof Mark: ExdIMb

Operating Environment:

Applicable to underground coal mine excavation working faces with methane mixture and coal dust explosion risks; locations without significant vibration; environments free of gases and vapors that damage metal insulation; areas with dripping water; motors shall operate normally on coal seam working faces with an inclination not exceeding 35°.

Main Terminal Box:

The terminal box is located on the top of the motor and is equipped with 6 terminals. The wire inlet adopts a rubber-sheathed cable structure. Four bolt holes for connecting the terminal box base to the motor frame are arranged inside the terminal box. The terminal box has a large internal space, which not only meets the requirements for electrical clearance and creepage distance at 1140V but also facilitates wiring operations in underground coal mines. The terminal box has sufficient mechanical strength; the connection between the terminal sleeve and the box base adopts a threaded flameproof structure, ensuring excellent flameproof performance and resistance to damage during maintenance and disassembly. The terminal bolts use a double-nut locking structure, which reduces local heat generation at the connection between the external cable and the terminal bolts and improves the connection reliability.

Depending on different starting requirements, the terminal box can be manufactured with one wire inlet (for direct motor starting) or two wire inlets (for Y-△ motor starting).

Stator:

The motor frame (a key part of the outer housing) is made of steel plates, providing high impact and collision resistance. Other outer housing components are made of gray cast iron with a grade not lower than HT250. The stator core is made of high-magnetic-permeability, low-loss high-quality electrical silicon steel sheets. The stator winding adopts Class F insulation; the coil ends are reliably fixed and bound. During manufacturing, the winding undergoes multiple interturn pulse voltage tests and ground withstand voltage tests, and is treated with the VPI (Vacuum Pressure Impregnation) solvent-free process. This process integrates the stator coil into a complete unit, endowing the winding and insulation with excellent electrical, mechanical, moisture-proof, corrosion-resistant, and thermal stability properties.

Rotor:

The rotor is a cast aluminum rotor. The rotor core is made of high-magnetic-permeability, low-loss high-quality electrical silicon steel sheets. The rotor is verified by dynamic balancing, ensuring stable motor operation, low vibration, and low noise.

Bearings:

The motor uses special rolling bearings for motors, which effectively suppress vibration and noise during operation. The allowable temperature of the bearings (measured by the thermometer method) shall not exceed 95℃.

Fan and Fan Cover:

Fans and shafts across the entire series are connected by keys, ensuring reliable operation. The fan cover adopts a steel plate structure; the fan cover cylinder is made of thick steel plates. The fan cover is fixed on the motor frame with an axial limit structure, achieving a large ventilation area while withstanding external impact from the axial direction and preventing the intrusion of foreign objects of a certain size. The protection class of the fan cover is IP20.

Environmental Conditions:

Ambient air temperature: -15℃～+40℃

Altitude: Not exceeding 1000m

(Note: If the motor is used at an altitude exceeding 1000m or in an environment where the maximum ambient air temperature is higher or lower than 40℃, it shall comply with the provisions of GB755.)

Humidity: Not exceeding 95% (at a temperature of 25℃)

Electrical Conditions:

The motor adopts Class F insulation. When the operating environment meets the specified electrical conditions for the motor, the temperature rise of the stator winding (measured by the resistance method) shall not exceed 85K (among which, for Frame Size 315L2 (4-pole) and Frame Size 355, the temperature rise shall not exceed 105K).

(Note: If the altitude and ambient temperature at the test site differ from those specified in the electrical conditions for the motor in this standard, the temperature rise limit shall be corrected in accordance with GB755.)

5. Ordering Guide

5.1 Factors to Consider When Selecting a Motor

Explosion-proof class: ExdIMb

Voltage: 380V, 660V, 380/660V, 660/1140V

Frequency: 50Hz

Mounting type: IMB3, IMB35, IMB5

Operating environment: Underground coal mine excavation working faces with methane mixture and coal dust explosion risks; locations without significant vibration; environments free of gases and vapors that damage metal insulation; areas with dripping water; motors shall operate normally on coal seam working faces with an inclination not exceeding 35°.

Protection class: IP55

Duty type: S1

5.2 Example

Requirements: Frame center height 180, 22kW, 2-pole frame with base, end cover without flange, ExdIMb, 660/1140V, clockwise rotation, bell mouth wire inlet.

Motor Marking:

Converted to contract terms: YBK3-180M-2 22kW 660/1140V 50Hz IMB3 Ex dI Mb Bell Mouth Inlet.

5.3 Additional Notes

For special requirements (such as voltage, frequency, protection class, rotation direction, mounting type, double shaft extension, noise, vibration limits, and terminal box wire inlet type), manufacturing can only be carried out after signing a technical agreement.

When placing an order, please specify the motor’s model, power, synchronous speed, voltage, frequency, structure, mounting type, and explosion-proof mark as indicated in this catalog.

Example: YBK3-315S-4 110kW 660/1140V ExdI Mb Class F B3

The data in this catalog is subject to change with technological progress without prior notice. Please pay attention to the catalog version.