YE2 Series High-Efficiency Three-Phase Asynchronous Motors: Technical Guide & Application Reference

1. Introduction

The YE2 series high-efficiency three-phase asynchronous motor represents a pivotal milestone in China’s industrial motor evolution — bridging the gap between legacy standard-efficiency designs and modern premium-efficiency requirements. Developed in response to GB 18613-2012 (China’s mandatory motor energy efficiency standard) and harmonized with IEC 60034-30-1 IE2 international efficiency classification, the YE2 series established the foundation for energy-conscious motor design in the Chinese manufacturing sector.

While subsequent regulatory updates (notably GB 18613-2020, effective June 1, 2021) have elevated the minimum efficiency requirement from IE2 to IE3 for most general-purpose motors, the YE2 series remains extensively deployed across existing industrial infrastructure, export markets with IE2 acceptance, and applications where IE2 represents the optimal balance of efficiency and capital cost. Understanding the YE2 series is therefore essential for maintenance engineers, procurement professionals, and system designers operating across diverse regulatory environments.

This guide provides a comprehensive technical reference for the YE2 series, covering design standards, performance characteristics, efficiency analysis, and practical application guidance.

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2. Regulatory Framework & Efficiency Classification

2.1 IEC 60034-30-1 Efficiency Classes

The International Electrotechnical Commission defines motor efficiency classes based on full-load efficiency at rated voltage and frequency:

表格

Efficiency Class	Designation	Typical Full-Load Efficiency (4-pole, 50 Hz, 75 kW)	Loss Reduction vs. IE1	Regulatory Status (Global)
IE1	Standard Efficiency	91.7%	Baseline	Phased out in EU, China, and most developed markets
IE2	High Efficiency	93.2%	~20% lower losses	Mandatory minimum in some regions; acceptable with VFD in EU
IE3	Premium Efficiency	94.5%	~35% lower losses	Mandatory minimum in EU (≥0.75 kW), China, Brazil, etc.
IE4	Super Premium Efficiency	95.6%	~50% lower losses	Voluntary premium; growing market share
IE5	Ultra-Premium Efficiency	96.7%	~60% lower losses	Emerging standard; limited commercial availability

2.2 GB 18613 Evolution: YE2’s Regulatory Context

表格

Standard Version	Effective Date	Minimum Efficiency Requirement	YE2 Compliance Status
GB 18613-2006	2008	EFF2 (approx. IE1)	Not applicable (pre-YE2 era)
GB 18613-2012	2012–2021.5.31	Grade 3 = IE2	YE2 fully compliant — mandatory minimum
GB 18613-2020	2021.6.1 onwards	Grade 3 = IE3	YE2 non-compliant for new domestic sales; IE3 (YE3) mandatory

Key Regulatory Notes:

• China domestic market (post-2021): YE2 motors can no longer be sold as new general-purpose motors for S1 duty applications within China. They may be sold for export, replacement parts, or exempt applications (integrated machines, submersible motors, etc.).
• Export markets: Many developing markets and specific industrial applications still accept IE2 as the minimum or reference efficiency level.
• EU market: IE2 motors may be placed on the market only if equipped with a Variable Frequency Drive (VFD) per Regulation (EU) 2019/1781.
• Retrofit applications: YE2 motors remain valid replacement units for existing IE1/IE2 installations where upgrading to IE3 is not economically justified.

2.3 Global MEPS Comparison (IE2 Relevance)

表格

Region / Country	Regulation	Scope	IE2 Status	Implementation Date
European Union	EU 2019/1781	0.12–1,000 kW, 2/4/6/8 poles	Allowed only with VFD	2021
China	GB 18613-2020	0.12–1,000 kW, 2/4/6/8 poles	Phased out for new sales	2021.6.1
USA	DOE 10 CFR 431	1–500 HP, 2/4/6/8 poles	Equivalent to NEMA Premium	2016
Brazil	ABNT NBR 17094	0.12–370 kW, 2/4/6/8 poles	Minimum (IE3 equivalent)	2019
Australia / NZ	GEMS Act 2019	0.73–185 kW, 2/4/6/8 poles	Minimum	2019
India	IS 12615	0.12–1,000 kW, 2/4/6/8 poles	Minimum (IE2 level)	2019
Switzerland	Adopted EU regs	0.12–1,000 kW	Allowed with VFD	2021
Turkey	Adopted EU regs	0.12–1,000 kW	Allowed with VFD	2021

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3. Design Standards & Construction

3.1 Compliance Standards

表格

Standard	Scope	YE2 Compliance
IEC 60034-1	Rotating electrical machines — Rating and performance	Full compliance
IEC 60034-2-1	Standard methods for determining losses and efficiency	Full compliance (IE2 testing)
IEC 60034-5	Degrees of protection provided by enclosures (IP code)	IP55 standard
IEC 60034-6	Methods of cooling (IC code)	IC411 (TEFC) standard
IEC 60034-7	Classification of types of construction and mounting	IM B3, B5, B35, etc.
IEC 60034-8	Terminal markings and direction of rotation	Full compliance
IEC 60034-12	Starting performance of single-speed motors	Tst​/Tn​ ≥ 1.8–2.2
IEC 60034-30-1	Efficiency classes of single-speed motors	IE2 class compliance
GB 18613-2012	Minimum allowable values of energy efficiency	Grade 3 compliance
GB 755-2008	Rotating electrical machines — Rating and performance	Full compliance
GB/T 1032	Test methods for three-phase induction motors	Full compliance

3.2 Construction Features

表格

Component	Specification	Engineering Benefit
Frame (H63–H160)	Die-cast aluminum alloy (ADC12)	Lightweight, excellent heat dissipation, corrosion resistance
Frame (H180–H355)	Cast iron (HT250)	High mechanical strength, vibration damping, durability
Stator Core	Cold-rolled silicon steel (50W470 or 50W600), 0.5 mm laminations	Low core loss, high magnetic permeability
Rotor Core	Same silicon steel as stator	Consistent magnetic properties, balanced losses
Rotor Bars	High-conductivity aluminum die-cast	Low rotor resistance, high starting torque, efficient energy conversion
End Rings	Aluminum integral with rotor bars	Robust construction, uniform current distribution
Winding Wire	QZ-2/155 (Class F) polyester-imide enameled copper	High thermal endurance, excellent dielectric strength
Insulation System	Class F (155°C) with Class B (130°C) temperature rise margin	25K safety margin ensures long insulation life
Shaft	45# carbon steel (H63–H132) or 40Cr alloy steel (H160–H355)	High strength, fatigue resistance, precise machining
Bearings	Deep groove ball bearings, C3 clearance (SKF, NSK, or equivalent)	Long life, low friction, high-speed capability
Terminal Box	Aluminum or cast iron, 360° rotatable	Flexible cable entry, IP55 protection
Cooling Fan	Glass-reinforced polypropylene (PP+GF30)	High strength, low noise, corrosion resistant
Fan Cover	Steel with electrophoretic coating	Impact protection, corrosion resistance
Terminal Block	High-quality brass with nickel plating	Low contact resistance, oxidation resistance

3.3 Model Nomenclature System

plain

YE2 - □□□ □ - □ - □
│      │   │   │   └── Mounting code (B3/B5/B35/V1/etc.)
│      │   │   └────── Pole number (2/4/6/8)
│      │   └────────── Core length code (S/M/L/1/2)
│      └─────────────── Frame size (center height in mm)
└────────────────────── Series designation (Y + E2 = IE2 Efficiency)

Example: YE2-132M-4-B3

• YE2: High-efficiency three-phase asynchronous motor (IE2 class)
• 132: Center height = 132 mm
• M: Medium frame length
• 4: 4-pole (1,500 r/min synchronous, ~1,440 r/min rated)
• B3: Foot-mounted, horizontal shaft

Example: YE2-160L-2-B35

• 160: Center height = 160 mm
• L: Long frame
• 2: 2-pole (3,000 r/min synchronous, ~2,900 r/min rated)
• B35: Foot-mounted with flange (large flange)

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4. Technical Specifications & Performance Data

4.1 Standard Operating Conditions

表格

Parameter	Specification
Rated Voltage	380 V (3-phase), 50 Hz (standard); 220–660 V on request
Voltage Tolerance	±5% of rated voltage (continuous operation)
Frequency	50 Hz (standard); 60 Hz available
Power Range	0.12 kW – 315 kW (standard series); up to 500 kW (extended)
Frame Size	H63 – H355 (IEC 60072)
Pole Number	2, 4, 6, 8 poles
Protection Class	IP55 (standard); IP54 / IP56 / IP65 (optional)
Insulation Class	Class F (155°C) with Class B (130°C) temperature rise
Cooling Method	IC411 (Totally Enclosed Fan-Cooled, TEFC)
Duty Type	S1 (Continuous Duty); S3, S4, S5, S6 on request
Connection	Star (Y) for ≤ 3 kW; Delta (Δ) for ≥ 4 kW
Ambient Temperature	-20°C to +40°C (standard); -40°C to +60°C (special)
Altitude	≤ 1,000 m (standard); > 1,000 m requires derating
Relative Humidity	≤ 90%
Mounting	B3, B5, B14, B34, B35, V1, V3, V5, V6, V15, V18

4.2 Efficiency Data — 2-Pole (3,000 r/min synchronous), 380V, 50Hz

表格

Model	Power (kW)	Speed (r/min)	Efficiency (%)	Power Factor	Current (A)	Tst​/Tn​	Tmax​/Tn​
YE2-801-2	0.75	2,825	77.4	0.83	1.75	2.2	2.3
YE2-802-2	1.1	2,825	79.6	0.84	2.42	2.2	2.3
YE2-90S-2	1.5	2,840	81.3	0.84	3.22	2.2	2.3
YE2-90L-2	2.2	2,840	83.2	0.85	4.50	2.2	2.3
YE2-100L-2	3.0	2,880	84.6	0.87	5.92	2.2	2.3
YE2-112M-2	4.0	2,890	85.8	0.88	7.62	2.2	2.3
YE2-132S1-2	5.5	2,900	87.0	0.88	10.2	2.0	2.3
YE2-132S2-2	7.5	2,900	88.1	0.89	13.5	2.0	2.3
YE2-160M1-2	11	2,930	89.4	0.89	19.3	2.0	2.3
YE2-160M2-2	15	2,930	90.3	0.89	25.8	2.0	2.2
YE2-160L-2	18.5	2,930	90.9	0.90	31.2	2.0	2.2
YE2-180M-2	22	2,940	91.3	0.90	36.8	2.0	2.2
YE2-200L1-2	30	2,950	92.0	0.90	49.5	2.0	2.2
YE2-200L2-2	37	2,950	92.5	0.90	60.5	2.0	2.2
YE2-225M-2	45	2,970	92.9	0.90	73.0	2.0	2.2
YE2-250M-2	55	2,970	93.2	0.90	88.5	2.0	2.2
YE2-280S-2	75	2,980	93.8	0.91	118.0	2.0	2.2
YE2-280M-2	90	2,980	94.1	0.91	140.0	2.0	2.2
YE2-315S-2	110	2,980	94.3	0.91	170.0	2.0	2.2
YE2-315M-2	132	2,980	94.6	0.91	203.0	2.0	2.2
YE2-315L1-2	160	2,980	94.8	0.92	243.0	2.0	2.2
YE2-315L-2	200	2,980	95.0	0.92	302.0	2.0	2.2

4.3 Efficiency Data — 4-Pole (1,500 r/min synchronous), 380V, 50Hz

表格

Model	Power (kW)	Speed (r/min)	Efficiency (%)	Power Factor	Current (A)	Tst​/Tn​	Tmax​/Tn​
YE2-801-4	0.55	1,405	71.0	0.75	1.50	2.4	2.3
YE2-802-4	0.75	1,405	73.0	0.76	1.92	2.3	2.3
YE2-90S-4	1.1	1,445	76.2	0.77	2.60	2.3	2.3
YE2-90L-4	1.5	1,445	78.5	0.79	3.36	2.3	2.3
YE2-100L1-4	2.2	1,440	81.0	0.81	4.65	2.3	2.3
YE2-100L2-4	3.0	1,440	82.6	0.82	6.10	2.3	2.3
YE2-112M-4	4.0	1,440	84.2	0.82	7.90	2.3	2.3
YE2-132S-4	5.5	1,440	85.7	0.83	10.6	2.2	2.3
YE2-132M-4	7.5	1,440	87.0	0.84	14.0	2.2	2.3
YE2-160M-4	11	1,450	88.4	0.85	20.0	2.2	2.3
YE2-160L-4	15	1,450	89.4	0.86	26.5	2.2	2.3
YE2-180M-4	18.5	1,455	90.0	0.86	32.5	2.0	2.3
YE2-180L-4	22	1,455	90.5	0.86	38.5	2.0	2.2
YE2-200L-4	30	1,460	91.4	0.86	51.5	2.0	2.2
YE2-225S-4	37	1,460	92.0	0.87	62.0	2.0	2.2
YE2-225M-4	45	1,460	92.5	0.87	74.5	2.0	2.2
YE2-250M-4	55	1,465	93.0	0.87	90.0	2.0	2.2
YE2-280S-4	75	1,470	93.6	0.88	120.0	2.0	2.2
YE2-280M-4	90	1,470	93.9	0.88	143.0	2.0	2.2
YE2-315S-4	110	1,470	94.2	0.88	173.0	2.0	2.2
YE2-315M-4	132	1,470	94.5	0.88	206.0	2.0	2.2
YE2-315L1-4	160	1,470	94.7	0.89	248.0	2.0	2.2
YE2-315L2-4	200	1,470	94.9	0.89	308.0	2.0	2.2
YE2-315L-4	250	1,470	95.1	0.89	382.0	2.0	2.2

4.4 Efficiency Data — 6-Pole (1,000 r/min synchronous), 380V, 50Hz

表格

Model	Power (kW)	Speed (r/min)	Efficiency (%)	Power Factor	Current (A)	Tst​/Tn​	Tmax​/Tn​
YE2-90S-6	0.75	910	75.9	0.71	2.10	2.0	2.1
YE2-90L-6	1.1	910	78.1	0.73	2.89	2.0	2.1
YE2-100L-6	1.5	940	79.8	0.75	3.80	2.0	2.1
YE2-112M-6	2.2	960	81.8	0.76	5.30	2.0	2.1
YE2-132S-6	3.0	960	83.3	0.76	7.00	2.0	2.1
YE2-132M1-6	4.0	960	84.6	0.76	9.20	2.0	2.1
YE2-132M2-6	5.5	960	86.0	0.77	12.3	2.0	2.1
YE2-160M-6	7.5	970	87.2	0.77	16.4	2.0	2.1
YE2-160L-6	11	970	88.4	0.78	23.5	2.0	2.1
YE2-180L-6	15	970	89.4	0.81	30.0	2.0	2.1
YE2-200L1-6	18.5	980	90.2	0.81	36.5	2.0	2.1
YE2-200L2-6	22	980	90.6	0.83	42.5	2.0	2.1
YE2-225M-6	30	980	91.4	0.84	56.5	2.0	2.1
YE2-250M-6	37	985	92.0	0.85	68.5	2.0	2.1
YE2-280S-6	45	985	92.5	0.86	82.0	2.0	2.1
YE2-280M-6	55	985	93.0	0.86	99.0	2.0	2.1
YE2-315S-6	75	990	93.6	0.86	134.0	2.0	2.1
YE2-315M-6	90	990	93.9	0.86	160.0	2.0	2.1
YE2-315L1-6	110	990	94.2	0.86	195.0	2.0	2.1
YE2-315L2-6	132	990	94.4	0.87	232.0	2.0	2.1
YE2-315L-6	160	990	94.6	0.87	280.0	2.0	2.1

4.5 8-Pole (750 r/min synchronous), 380V, 50Hz

表格

Model	Power (kW)	Speed (r/min)	Efficiency (%)	Power Factor	Current (A)	Tst​/Tn​	Tmax​/Tn​
YE2-132S-8	2.2	710	80.0	0.68	5.80	1.8	2.0
YE2-132M-8	3.0	710	81.5	0.70	7.50	1.8	2.0
YE2-160M1-8	4.0	720	82.9	0.72	9.70	1.9	2.0
YE2-160M2-8	5.5	720	84.3	0.74	12.8	1.9	2.0
YE2-160L-8	7.5	720	85.6	0.75	17.0	1.9	2.0
YE2-180L-8	11	730	87.0	0.76	24.0	1.9	2.0
YE2-200L-8	15	730	88.0	0.78	31.5	1.9	2.0
YE2-225S-8	18.5	735	88.8	0.79	38.0	1.9	2.0
YE2-225M-8	22	735	89.3	0.80	44.5	1.9	2.0
YE2-250M-8	30	735	90.3	0.81	59.5	1.9	2.0
YE2-280S-8	37	740	90.8	0.82	72.0	1.9	2.0
YE2-280M-8	45	740	91.3	0.83	86.5	1.9	2.0
YE2-315S-8	55	740	91.8	0.83	105.0	1.9	2.0
YE2-315M-8	75	740	92.4	0.84	141.0	1.9	2.0
YE2-315L1-8	90	740	92.8	0.84	168.0	1.9	2.0
YE2-315L2-8	110	740	93.1	0.85	203.0	1.9	2.0
YE2-315L-8	132	740	93.4	0.85	242.0	1.9	2.0

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5. Efficiency Analysis & Loss Breakdown

5.1 Motor Loss Components

The total losses in an induction motor comprise five principal components:

Ploss​=Pstator_cu​+Protor_cu​+Piron​+Pfriction_windage​+Pstray​

Where:

• Pstator_cu​ = Stator copper losses (I2R )
• Protor_cu​ = Rotor copper (aluminum) losses
• Piron​ = Core losses (hysteresis + eddy current)
• Pfriction_windage​ = Mechanical losses
• Pstray​ = Stray load losses

Typical Loss Distribution — YE2-160M-4 (11 kW, IE2):

表格

Loss Component	IE1 (Baseline)	IE2 (YE2)	IE3 (YE3)	Reduction Strategy
Stator copper loss	32%	28%	24%	Increased copper cross-section; optimized slot design
Rotor aluminum loss	18%	16%	14%	Optimized rotor slot geometry; higher conductivity alloy
Core (iron) loss	28%	25%	22%	Thinner laminations (0.5→0.35 mm); higher grade silicon steel
Friction & windage	12%	12%	12%	Optimized fan design; reduced bearing friction
Stray load loss	10%	9%	8%	Improved winding distribution; reduced harmonic content
Total losses	100%	90%	80%	—

5.2 Efficiency Improvement: YE2 vs. IE1 (Y Series)

表格

Power (kW)	IE1 Efficiency (%)	YE2 Efficiency (%)	Absolute Improvement	Relative Loss Reduction	Annual Savings @ 6,000 h ($0.12/kWh)
0.75	72.1	77.4	+5.3%	19.0%	$42
1.5	77.4	81.3	+3.9%	17.1%	$52
3.0	81.4	84.6	+3.2%	17.3%	$82
5.5	84.1	87.0	+2.9%	18.3%	$132
11	87.6	89.4	+1.8%	14.5%	$148
18.5	89.2	90.0	+0.8%	7.4%	$88
30	90.7	91.4	+0.7%	7.5%	$140
55	92.0	93.0	+1.0%	12.5%	$360
90	93.0	93.9	+0.9%	12.9%	$524
160	93.9	94.7	+0.8%	13.2%	$818

Key Observation: The absolute efficiency improvement is most pronounced at lower power ratings (where baseline efficiency is lowest), while the economic impact is greatest at higher power ratings (where energy consumption is highest).

5.3 IE2 vs. IE3: Upgrade Economics

表格

Power (kW)	IE2 Efficiency (%)	IE3 Efficiency (%)	Efficiency Gain	Incremental Cost (%)	Simple Payback (years) @ 6,000 h/year
1.5	81.3	85.5	+4.2%	15–20%	1.8–2.4
5.5	87.0	89.2	+2.2%	12–18%	2.5–3.8
11	89.4	91.2	+1.8%	10–15%	3.0–4.5
22	90.5	92.1	+1.6%	8–12%	3.5–5.2
45	92.5	93.6	+1.1%	6–10%	4.5–7.5
90	93.9	94.8	+0.9%	5–8%	5.5–8.8
160	94.7	95.4	+0.7%	4–7%	7.0–12.3

Conclusion: The economic case for upgrading from IE2 to IE3 is strongest at low-to-medium power ratings (≤ 22 kW) with high operating hours. At very high power ratings, the incremental efficiency gain is small and payback periods extend significantly.

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6. Dimensional Data & Mounting Configurations

6.1 Foot-Mounted (B3) Dimensions — Selected Frame Sizes

表格

Frame	A	B	C	D	E	F	G	H	K	L
80	125	100	50	19	40	6	15.5	80	10	285
90S	140	100	56	24	50	8	20	90	10	320
90L	140	125	56	24	50	8	20	90	10	345
100L	160	140	63	28	60	8	24	100	12	380
112M	190	140	70	28	60	8	24	112	12	400
132S	216	140	89	38	80	10	33	132	12	470
132M	216	178	89	38	80	10	33	132	12	508
160M	254	210	108	42	110	12	37	160	14.5	600
160L	254	254	108	42	110	12	37	160	14.5	644
180M	279	241	121	48	110	14	42.5	180	14.5	690
180L	279	279	121	48	110	14	42.5	180	14.5	728
200L	318	305	133	55	110	16	49	200	18.5	780
225S	356	286	149	60	140	18	53	225	18.5	820
225M	356	311	149	60	140	18	53	225	18.5	845
250M	406	349	168	65	140	18	58	250	24	935
280S	457	368	190	75	140	20	67.5	280	24	1,020
280M	457	419	190	75	140	20	67.5	280	24	1,071
315S	508	406	216	80	170	22	71	315	28	1,150
315M	508	457	216	80	170	22	71	315	28	1,201
315L	508	508	216	80	170	22	71	315	28	1,252

All dimensions in millimeters (mm). Dimensional tolerances per IEC 60072.

6.2 Flange-Mounted (B5) Dimensions

表格

Frame	D	E	F	G	M	N	P	S	T	L
80	19	40	6	15.5	165	130	200	12	3.5	285
90S/L	24	50	8	20	165	130	200	12	3.5	320–345
100L	28	60	8	24	215	180	250	14.5	4	380
112M	28	60	8	24	215	180	250	14.5	4	400
132S/M	38	80	10	33	265	230	300	14.5	4	470–508
160M/L	42	110	12	37	300	250	350	18.5	5	600–644
180M/L	48	110	14	42.5	300	250	350	18.5	5	690–728
200L	55	110	16	49	350	300	400	18.5	5	780
225S/M	60	140	18	53	400	350	450	18.5	5	820–845
250M	65	140	18	58	500	450	550	18.5	5	935
280S/M	75	140	20	67.5	500	450	550	18.5	5	1,020–1,071
315S/M/L	80	170	22	71	600	550	660	24	6	1,150–1,252

6.3 Mounting Configuration Availability

表格

Code	Description	H63–H112	H132–H160	H180–H225	H250–H355
B3	Foot-mounted, horizontal shaft	✓	✓	✓	✓
B5	Flange-mounted, large flange (FF)	✓	✓	✓	✓
B14	Flange-mounted, small flange (FT)	✓	✓	—	—
B35	Foot + large flange	✓	✓	✓	✓
B34	Foot + small flange	✓	✓	—	—
V1	Vertical, shaft downward	✓	✓	✓	✓
V3	Vertical, shaft upward	✓	✓	—	—
V5	Wall-mounted, shaft left	✓	✓	—	—
V6	Wall-mounted, shaft right	✓	✓	—	—
V15	Vertical + flange, shaft down	✓	✓	—	—
V18	Vertical + small flange	✓	—	—	—

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7. Torque Characteristics & Starting Performance

7.1 Torque-Speed Relationship

The electromagnetic torque of an induction motor is given by:

T=2πf3p​⋅(R1​+sR2′​​)2+(X1​+X2′​)2V12​⋅sR2′​​​

Where:

• p = Pole pairs
• f = Supply frequency (Hz)
• V1​ = Stator phase voltage (V)
• R1​ , X1​ = Stator resistance and reactance
• R2′​ , X2′​ = Rotor resistance and reactance (referred to stator)
• s = Slip

Slip at Rated Load:

sn​=ns​ns​−nr​​×100%

表格

Pole Number	Synchronous Speed (r/min)	Typical Rated Speed (r/min)	Typical Slip (%)
2	3,000	2,890–2,980	0.7–3.7
4	1,500	1,440–1,470	2.0–4.0
6	1,000	960–990	1.0–4.0
8	750	710–740	1.3–5.3

7.2 Starting Performance Parameters

表格

Parameter	Symbol	Typical Value	Significance
Locked-rotor torque ratio	Tst​/Tn​	1.8–2.4	Ability to start under load
Pull-up torque ratio	Tpu​/Tn​	1.6–2.2	Ability to accelerate through speed range
Breakdown torque ratio	Tmax​/Tn​	2.0–2.5	Overload capability before stall
Locked-rotor current ratio	Ist​/In​	6.0–8.0	Starting current impact on grid
Starting time	tstart​	1–10 s	Function of load inertia and torque

Starting Torque Requirements by Load Type:

表格

Load Type	Required Tst​/Tn​	YE2 Suitability	Starting Method
Centrifugal pump	1.2–1.5	Excellent	DOL up to 5.5 kW
Fan (low inertia)	1.3–1.8	Excellent	DOL up to 11 kW
Fan (high inertia)	1.8–2.5	Good	Star-delta or soft starter
Compressor (unloaded)	1.5–2.0	Excellent	DOL or star-delta
Compressor (loaded)	2.0–2.5	Good	Soft starter or DOL with clutch
Conveyor (empty)	1.5–2.0	Excellent	DOL
Conveyor (loaded)	2.0–2.8	Marginal	High-torque motor or soft starter
Mixer (liquid)	1.2–1.8	Excellent	DOL
Mixer (viscous)	2.0–3.0	Marginal	High-slip or VFD
Crane / Hoist	2.5–3.5	Poor	High-slip or specialized motor

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8. Application Engineering

8.1 Industry Application Matrix

表格

Industry Sector	Typical Application	Preferred YE2 Spec	Duty Considerations
Water Supply & Treatment	Raw water pumps, booster pumps, filter feed	4-pole, IP55, cast iron frame	Continuous duty; possible VFD
HVAC	Chilled water pumps, hot water circulation, cooling towers	4-pole or 6-pole, IP55, aluminum frame	Continuous duty; variable load
Irrigation	Surface pumps, booster stations, center pivot	2-pole or 4-pole, IP55, cast iron	Seasonal; outdoor installation
Food & Beverage	Mixers, conveyors, packaging machinery	4-pole, IP55 or IP65, aluminum	Washdown duty; food-grade options
Textile	Spinning frames, looms, winding machines	4-pole, IP55, low vibration	High-speed precision; low noise
Printing	Press drives, folder units, conveyor systems	4-pole, IP55, B5 mounting	Continuous duty; speed stability
Machine Tools	Lathe spindles, milling heads, grinding machines	2-pole or 4-pole, B3 or B5	High starting torque; precision
Material Handling	Belt conveyors, bucket elevators, screw conveyors	4-pole or 6-pole, high torque	Intermittent duty; high inertia
Mining & Quarrying	Crushers, screens, conveyors, pumps	4-pole, IP55, cast iron, C3 bearings	Dust; vibration; heavy duty
Cement	Kiln drives, mill drives, fan drives	4-pole or 6-pole, IP55, cast iron	High ambient; dust; continuous
Oil & Gas	Pump jacks, transfer pumps, compressor drives	4-pole, IP55 or IP56, cast iron	Hazardous area options; outdoor
Marine	Bilge pumps, fire pumps, HVAC fans	4-pole, IP56, cast iron or aluminum	Vibration; inclination; corrosion
Agriculture	Grain dryers, feed mills, irrigation pumps	4-pole, IP55, aluminum or cast iron	Seasonal; outdoor; dust
General Industry	Compressors, fans, pumps, mixers	2/4/6-pole per application	Standard configuration

8.2 Pump Application Power Sizing

For centrifugal pump applications (the most common YE2 application):

Hydraulic Power:

Phydraulic​=367Q×H​ [kW]

Required Motor Power:

Pmotor​=367×ηp​×ηm​Q×H​×SF

Where:

• Q = Flow rate (m³/h)
• H = Total dynamic head (m)
• ηp​ = Pump efficiency (typically 0.60–0.85)
• ηm​ = Motor efficiency (from YE2 tables)
• SF = Service factor (1.10–1.15 for pumps)

Sizing Example:

Application: HVAC chilled water circulation pump

• Q = 80 m³/h, H = 32 m
• Pump efficiency = 75%
• YE2-132S-4 selected (5.5 kW, 85.7% efficiency)

Pmotor​=367×0.75×0.85780×32​×1.10=235.62,560​×1.10=11.94 kW

Selected: YE2-160M-4 (11 kW) — slightly below calculated but within acceptable margin for pump service factor. Next size up (15 kW) would operate at part load with reduced efficiency.

8.3 Variable Frequency Drive (VFD) Compatibility

表格

Parameter	YE2 with VFD	Notes
Minimum speed	25–30 Hz (50%–60% of rated)	Below this, motor cooling may be insufficient
Maximum speed	50–55 Hz (100%–110% of rated)	Do not exceed without manufacturer approval
Recommended VFD type	Scalar (V/Hz) or Sensorless Vector	Vector control preferred for torque-critical applications
Switching frequency	2–4 kHz	Lower reduces motor heating; higher reduces noise
Cable length	< 50 m without filter; < 150 m with dv/dt filter	Long cables cause voltage reflection
Bearing protection	Recommended for > 30 kW or cable > 50 m	Shaft grounding brush or insulated bearing
Derating	5–10% below 30 Hz	Reduced self-cooling at low speed

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9. Comparative Analysis: YE2 vs. Alternative Motor Series

表格

Evaluation Criteria	YE2 (IE2)	Y3/YE3 (IE3)	YX3/YE4 (IE4)	Y Series (IE1)
Efficiency class	IE2 (High)	IE3 (Premium)	IE4 (Super Premium)	IE1 (Standard)
Full-load efficiency (4-pole, 11 kW)	88.4%	91.2%	92.5%	87.6%
Purchase price index	100 (baseline)	110–120	130–150	85–90
Operating cost (6,000 h/year, 11 kW)	$1,056/year	$1,024/year	$1,008/year	$1,120/year
Annual energy savings vs. IE1	$64/year	$96/year	$112/year	—
Simple payback vs. IE1	2.3–3.1 years	3.1–4.6 years	4.5–6.7 years	—
China domestic market (post-2021)	Restricted	Fully compliant	Fully compliant	Phased out
Export market acceptance	Good	Excellent	Premium niche	Declining
Availability	Good (existing stock)	Excellent	Moderate (growing)	Limited
Spare parts interchangeability	Standard IEC	Standard IEC	Standard IEC	Standard IEC
Best application	Export markets; retrofit; cost-sensitive	New installations; high-run hours	Continuous duty; energy-critical	Non-regulated markets only

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10. Quality Assurance & Certifications

表格

Certification	Standard	Scope	YE2 Status
CCC	GB standards	China Compulsory Product Certification	Certified (pre-2021)
CE Marking	EU Low Voltage Directive 2014/35/EU	European market access	Certified
ISO 9001	ISO 9001:2015	Quality management systems	Certified
IEC	IEC 60034 series	International electrotechnical standards	Compliant
EAC	TR CU 004/2011	Eurasian Customs Union	Certified
CSA	CSA C390	Canadian market (optional)	Available on request
UL	UL 1004	North American market (optional)	Available on request
Energy Label (China)	CEL007	China Energy Label	Grade 3 (pre-2021)

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11. Maintenance & Troubleshooting

11.1 Preventive Maintenance Schedule

表格

Interval	Component	Action	Indicator of Required Service
Monthly	Bearing temperature	Record readings	Rising trend > 2°C/month
Monthly	Vibration	Measure and record	Increase > 10% from baseline
Quarterly	Terminal connections	Check tightness	Loose, discolored, or corroded terminals
Quarterly	Cooling fan	Inspect for damage	Cracks, imbalance, debris buildup
Semi-annually	Insulation resistance	Megger test (500V DC)	< 100 MΩ
Semi-annually	Bearings (greased)	Regrease per manufacturer	Extended grease life indicators
Annually	Coupling alignment	Laser or dial check	Deviation > 50% of installation spec
Annually	Winding resistance	Measure phase-to-phase	Imbalance > 2%
Every 2 years	Bearings (oil-lubricated)	Oil analysis	Contamination, viscosity change, metal particles
Every 3–5 years	Bearings	Replace (predictive)	Vibration, temperature trends

11.2 Common Faults & Remedies

表格

Symptom	Probable Cause	Diagnostic Action	Corrective Measure
Motor overheating	Overload; low voltage; high ambient; blocked cooling; bearing failure	Check current vs. nameplate; measure voltage; measure ambient; inspect cooling; vibration analysis	Reduce load; improve supply; improve ventilation; clean cooling; replace bearings
Excessive vibration	Unbalance; misalignment; bearing wear; looseness; bent shaft	Balance check; alignment; vibration spectrum; bolt torque; runout check	Rebalance; realign; replace bearings; tighten; straighten shaft
High current	Overload; low voltage; single-phasing; mechanical binding	Compare to nameplate; measure voltage; check phase balance; rotate by hand	Reduce load; correct supply; repair electrical; free mechanical binding
Low torque / slow acceleration	Low voltage; wrong connection (star instead of delta); rotor defect	Measure voltage; verify connection; current signature analysis	Correct supply; correct wiring; repair rotor
Noise (electrical hum)	Single-phasing; loose laminations; inverter harmonics	Check phase balance; inspect core; measure THD	Repair supply; replace motor; install filter
Noise (mechanical)	Bearing failure; rubbing; loose fan; coupling wear	Vibration analysis; visual inspection	Replace bearing; correct clearance; tighten fan; replace coupling
Insulation failure	Moisture; overheating; contamination; voltage surge	Megger test; inspect windings; check for water ingress	Dry windings; correct cause; rewind or replace

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12. Conclusion

The YE2 series high-efficiency three-phase asynchronous motor occupies a significant position in the evolution of industrial motor efficiency. As the first Chinese motor series purpose-designed to meet IE2 / GB 18613-2012 Grade 3 efficiency requirements, the YE2 established the technical and commercial foundation for subsequent IE3 and IE4 developments.

For procurement professionals and system designers, the YE2 series offers:

• Proven efficiency: 20% lower losses than IE1 (Y series) motors, delivering measurable energy savings
• Global interchangeability: IEC standard dimensions ensure compatibility with existing installations and spare parts
• Regulatory flexibility: Acceptable for export markets and exempt applications where IE3 is not mandated
• Cost-effectiveness: Lower capital cost than IE3/IE4 alternatives, with reasonable payback periods for moderate-run applications
• Mature supply chain: Extensive manufacturing base and spare parts availability

However, the regulatory landscape has shifted decisively toward IE3 as the new baseline. For new installations in regulated markets (China domestic, EU, Brazil, Australia), YE3 (IE3) or higher should be specified. The YE2 series is best reserved for:

1. Export markets where IE2 remains the accepted standard
2. Replacement applications where upgrading to IE3 is not economically justified
3. Exempt applications (integrated machines, submersible motors, special duty)
4. Cost-sensitive projects with low operating hours where IE3 payback exceeds acceptable thresholds

By understanding the YE2 series’ capabilities, limitations, and regulatory context, engineers can make informed motor selection decisions that balance efficiency, cost, and compliance requirements.

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All technical data conforms to IEC 60034-30-1 (IE2 efficiency class), GB 18613-2012 (Grade 3), and IEC 60034-2-1 testing methodology. For application-specific motor selection in regulated markets, verify current local requirements as efficiency mandates continue to evolve globally.