YE3, YE4 and YE5 are the mainstream totally enclosed fan-cooled (TEFC) high-efficiency three-phase asynchronous motors supporting industrial fans, water pumps, compressors and machine tools. Classified in accordance with the GB18613-2020 Chinese National Standard and IEC60034-30 International Energy Efficiency Specification, they feature progressively higher energy efficiency, higher procurement cost and lower operating power consumption from YE3 to YE5. The motor selection is mainly determined by four core factors: annual operating hours, load conditions, project energy-saving policies and payback period of investment.
I. Core Differences: Energy Efficiency, Parameters, Structure and Cost Comparison
The current national standard (implemented in June 2021, GB18613-2020) defines three energy efficiency grades: YE3 = National Grade 3 (IE3), YE4 = National Grade 2 (IE4), YE5 = National Grade 1 (IE5), corresponding to the statutory minimum market entry level, mid-range energy-saving type and top ultra-high efficiency type for motors in China respectively.
Item | YE3 (IE3 / National Grade 3) | YE4 (IE4 / National Grade 2) | YE5 (IE5 / National Grade 1) |
Energy Efficiency Positioning | Basic high efficiency, minimum market entry standard | Mid-range energy-saving type | Top ultra-high efficiency, highest domestic standard |
Efficiency (4-pole, 55kW) | 95.0% | 95.8% | 96.5% |
Power Factor | 0.88 | 0.89 | 0.90 |
Noise (dB) | 72 | 70 | 68 |
Vibration (mm/s) | 2.8 | 2.3 | 2.0 |
Material & Structure | Conventional cold-rolled silicon steel, standard winding | High-grade silicon steel, optimized iron core and air duct | Ultra-thin high-permeability silicon steel, compact winding, optimized heat dissipation shell |
Procurement Cost Benchmark | 100% (benchmark price) | +12%~18% | +25%~35% |
Loss Reduction Benchmark | Reference value | About 15% lower loss than YE3 | About 30% lower loss than YE3 |
1. Basic Characteristics of YE3 Motors
Compliance Bottom Line: It is the mandatory minimum entry standard for new industrial projects, replacing obsolete Y/Y2 low-efficiency motors. It covers a complete specification range with frame size H80~450, power 0.55~1000kW and 2~12 poles.
Cost-Performance Advantage: It has the lowest procurement cost and strongest universality. The installation dimensions are compatible with old motor models, requiring no modification to the base and transmission structure during on-site replacement.
Disadvantage: It has relatively high power consumption under long-term continuous full-load operation, with prominent power loss for annual operating hours exceeding 4,000 hours.
2. Mid-Range Energy-Saving Characteristics of YE4 Motors
Upgraded Energy Efficiency: Adopting IE4 Grade 2 energy efficiency, it bridges basic high efficiency and ultra-high efficiency, serving as the mainstream model for domestic energy-saving renovation. It covers mainstream specifications of 0.12~450kW and 2~8 poles.
Optimized Performance: The iron core and winding are optimally designed with lower temperature rise and lower failure rate than YE3 motors, suitable for medium and long-term continuous operation equipment.
Moderate Economy: The cost premium is controllable. For most working conditions, the additional procurement cost can be recovered through power saving within 1.5 to 3 years.
3. Top Ultra-High Efficiency Characteristics of YE5 Motors
Highest National Standard Level: It complies with IE5 Grade 1 ultra-high energy efficiency, with full-series F-class insulation and IP55 protection. Adopting ultra-thin high-grade magnetic conductive silicon steel for the iron core, it minimizes copper loss and iron loss, featuring sufficient temperature rise margin and longer service life.
Low Noise & Low Vibration: The optimized ventilation structure delivers the lowest noise and vibration among the three models, meeting the strict environmental noise reduction requirements of precision workshops.
High Initial Investment: It has the highest upfront procurement cost but maximizes power-saving benefits during long-term operation, making it the preferred choice for dual-carbon goals and energy-saving subsidy projects.
II. Four Practical Principles for Motor Selection
Principle 1: Selection by Annual Operating Hours (Core Indicator)
Annual Operating Hours ＜ 3000h (Intermittent Working Condition): Prioritize YE3For short-time start-stop equipment such as small machine tools, intermittent mixers, standby pumps and temporary supporting fans, frequent start-stop and high no-load ratio result in limited annual power-saving benefits, which cannot cover the premium of YE4/YE5 motors. YE3 motors deliver optimal cost performance and meet national compliance requirements.
Annual Operating Hours 3000~6000h (Medium-Long Term Continuous Operation): Prioritize YE4For general circulating water pumps, dust removal fans, conventional compressors and conveying equipment used in chemical, building material, grain and oil production lines with over half-year annual operation, YE4 motors balance initial investment and energy saving, with the extra cost recovered via power saving in 2 to 3 years.
Annual Operating Hours ＞ 6000h (24/7 Uninterrupted Operation): Prioritize YE5For municipal water supply pumps, boiler induced draft fans, main mine conveyors, chemical circulating units and central air-conditioning main motors with all-weather continuous operation, electricity cost dominates operation and maintenance expenses. YE5 motors achieve significant long-term power-saving advantages and are the first choice for energy-saving renovation of high-energy-consuming enterprises, eligible for local energy-saving subsidies.
Principle 2: Selection by Policy and Project Attributes
YE4/YE5 for Old Equipment Renovation, Green Factory and Carbon Neutrality ProjectsLocal energy-saving subsidies and energy consumption quota management policies require main motors to reach at least IE4 (YE4) level. IE5 (YE5) motors are gradually configured as standard for new projects in high-energy-consuming industries including metallurgy, chemical industry and papermaking.
YE3 for Ordinary Non-Standard Equipment, Small Auxiliary Machines and Projects Without Energy Consumption AssessmentYE3 motors are applicable to general small-power auxiliary equipment and standby drive devices with no energy consumption assessment, meeting national standards and controlling equipment costs.
Principle 3: Selection by Service Environment and Operation & Maintenance Requirements
Prioritize YE4/YE5 for High-Temperature, Dust-Heavy and Harsh Working ConditionsYE4 and YE5 motors adopt optimized heat dissipation structures with lower temperature rise, slowing down insulation aging in harsh environments and reducing maintenance frequency and downtime maintenance costs compared with YE3 motors.
Prioritize YE5 for Clean Workshops, Food, Pharmaceutical and Precision EquipmentThe low vibration and low noise characteristics of YE5 motors avoid vibration interference with precision production lines, complying with environmental protection and noise reduction specifications for clean workshops.
Principle 4: Refined Selection by Power Rating
0.12~7.5kW Small-Power Auxiliary Motors: YE3 for most intermittent working conditions; YE4 for continuously operated small pumps and fans.
11kW and Above Medium/High-Power Main Motors: YE4 for continuous operation; YE5 directly for 22kW+ motors under 24/7 full-load operation. High-power motors have large power consumption base, so energy efficiency improvement brings multiplied electricity cost savings.
III. Key Selection Precautions
Prohibit Downgrade Selection Against National Standards: Obsolete low-efficiency motors such as Y/Y2 are banned from operation. YE3 is the minimum standard configuration, and YE3 cannot replace YE4/YE5 to evade energy consumption control in high-energy-consuming industries.
Frequency Conversion Matching Selection: Prioritize YE4P/YE5P special frequency conversion motors for variable-frequency working conditions. The customized optimized winding adapts to frequency conversion harmonics and reduces additional operating losses.
Explosion-Proof Scenario Extension: Corresponding explosion-proof models are YBX3 (YE3 explosion-proof), YBX4 (YE4 explosion-proof) and YBX5 (YE5 explosion-proof), with the same energy efficiency grading and selection logic as standard YE series motors.
Avoid Only Focusing on Unit Price: Blindly choosing low-cost YE3 motors for long-term operating equipment saves initial procurement cost but results in huge extra long-term electricity expenses and higher comprehensive operation and maintenance costs.
IV. Quick Selection Summary
Intermittent Short-Term Operation & Cost Control → YE3 (IE3 National Grade 3)
Long-Term Continuous Operation & Balanced Investment → YE4 (IE4 National Grade 2)
24/7 Full-Load Operation, Energy-Saving Renovation & High-Energy-Consuming Industries → YE5 (IE5 National Grade 1)
Hengda Motor has long focused on the R&D, production and after-sales service of high-efficiency motors. With advanced technologies, sophisticated equipment and lean manufacturing processes, the company delivers dependable products and satisfactory after-sales support, providing customers with customized professional motor solutions to maximize social value.
