YE2 Series Three-Phase Induction Motors

The YE2 series three-phase induction motor is a totally enclosed, self-fan-cooled, squirrel-cage motor built for continuous duty on fans, pumps and other equipment that runs under long-term load. Where a standard-efficiency motor turns a large share of its input into heat, the YE2 design works at the IE3 efficiency class defined in IEC 60034-30-1, and the gains are largest exactly where they matter most — machines that run thousands of hours a year rather than cycling on and off.

For a plant operator the case for IE3 is arithmetic, not marketing. A motor running continuously on a pump or fan consumes its own purchase price in electricity many times over during its service life, so a few percentage points of efficiency translate into a recurring saving on every operating hour. Across the YE2 range, peak efficiency reaches 95.2% in the 2-pole group and 94.1% in the 6-pole group, against 80.7% and 78.9% respectively at the smallest 0.75 kW ratings — which is why correct frame and pole selection matters as much as the series itself.

The series covers 0.75 kW to 90 kW across frame centre heights H80 to H280, with 2, 4, 6 and 8 pole options, IP55 enclosure protection as standard and Class F insulation with temperature rise evaluated to Class B. Mounting dimensions and power ratings conform to IEC 60072-1, and losses and efficiency are determined in accordance with IEC 60034-2-1, so published efficiency figures can be verified against a test report rather than taken on trust.

Key Features

IE3 efficiency class (IEC 60034-30-1)

• – the motor itself is the efficiency upgrade; no drive or control change is required.

Up to 15% lower energy consumption

• than IE2-class standard motors on continuous-duty applications.

Peak efficiency 95.2% (2-pole) and 94.1% (6-pole)

• – efficiency rises with frame size across the 0.75 kW to 90 kW range.

S1 continuous duty rating

• – designed for uninterrupted operation, the duty type where efficiency gains accumulate fastest.

Optimised for fans and pumps

• – running characteristics matched to the long-term load profile of fluid-moving equipment.

Class F insulation, 80 K temperature rise evaluation

• – a large temperature rise margin translates into longer insulation life and fewer rewinds.

Die-cast aluminium rotor

• – high operational reliability with consistent performance across the production run.

IP55 enclosure protection

• – dust-tight and water-jet protected for general plant environments.

IEC 60072-1 mounting dimensions

• – drop-in replacement on an existing IEC-frame baseplate.

Power range 0.75 kW to 90 kW, frames H80 to H280

• – one series for fractional and mid-range drives.

Energy Efficiency & Savings

Efficiency in the YE2 series is not a single number — it is a curve that rises with frame size and varies with pole count. The values below are taken from the series technical parameter tables.

Rating	Poles	Speed at 50 / 60 Hz	Efficiency
0.75 kW	2	3000 / 3600 r/min	80.7%
0.75 kW	6	1000 / 1200 r/min	78.9%
30 kW	6	1000 / 1200 r/min	92.9%
Series peak, 2-pole	2	3000 / 3600 r/min	95.2%
Series peak, 6-pole	6	1000 / 1200 r/min	94.1%

Three practical consequences follow from this curve:

Frame size drives efficiency.

• The gap between a 0.75 kW and a 90 kW motor is more than ten percentage points. Specifying the correct frame for the load, rather than the smallest frame that will start it, is the single largest efficiency decision available.

Pole count matters.

• At the same output, a 2-pole motor is generally more efficient than a 6-pole one because it has lower per-unit losses at higher speed. Where the driven machine accepts higher speed, the 2-pole version is usually the better choice.

Savings compound with running hours.

• An efficiency gain of a few percentage points applied to a motor running 6000 hours a year delivers a substantially different payback than the same gain on an intermittent duty. Continuous-duty fans and pumps are the applications where IE3 pays for itself fastest.

Efficiency gains should always be confirmed against the technical parameter table for the specific model, since values vary by frame, pole count and voltage.

Specifications

Parameter	Details
Series	YE2 high-efficiency three-phase induction motor
Construction	Totally enclosed, self-fan-cooled, squirrel-cage
Power range	0.75 kW – 90 kW
Frame centre height	H80 – H280
Poles	2, 4, 6, 8
Efficiency class	IE3 (IEC 60034-30-1)
Peak efficiency	95.2% (2-pole range); 94.1% (6-pole range)
Energy saving	Up to 15% versus IE2-class standard motors
Insulation class	Class F, temperature rise evaluated to Class B; Class H available
Enclosure protection	IP55 (IP54 available)
Cooling method	IC411
Duty type	Continuous duty (S1)
Temperature rise	Evaluated at 80 K, giving a large thermal margin
Rotor	Die-cast aluminium
Mounting	To IEC 60072-1

Operating Conditions

Condition	Value
Ambient temperature	-15 °C to +40 °C
Altitude	Not exceeding 1000 m
Rated voltage	380 V; any voltage between 220 V and 760 V available
Frequency	50 Hz / 60 Hz
Connection	Star (Y) for motors rated 3 kW and below; Delta (△) for motors rated 4 kW and above
Duty type	Continuous duty (S1)
Degree of protection	IP55 (IP54 available)
Insulation class	Class F, temperature rise evaluated to Class B; Class H available
Cooling method	IC411

Efficiency & Technical Data

Each model in the series is published with a full set of performance data so the efficiency case can be checked model by model:

Rated output (kW and HP)

• – the mechanical output at rated load.

Rated current (IFL, A)

• – published for 380–420 V / 50 Hz and 440–480 V / 60 Hz, and for individual voltages including 380 V, 400 V, 440 V, 460 V and 480 V.

Rated speed (r/min)

• – at 50 Hz and the corresponding 60 Hz speed for each pole group.

Efficiency (EEF, %)

• – determined in accordance with IEC 60034-2-1.

Power factor (cos φ)

• – used with efficiency to calculate input current and apparent power.

Rated torque (N·m)

• – for coupling and mechanical sizing.

Locked-rotor torque, locked-rotor current and maximum torque ratios

• – starting performance for direct-on-line applications.

Noise level (dB)

• – for installations with acoustic limits.

Weight (kg)

• – from 15 kg on the smallest H80 2-pole frame upward through the range; see the technical parameter table for each model.

Applications

Fans and blowers

• – continuous air movement where efficiency gains accumulate over thousands of running hours.

Water pumps and process pumps

• – long-term load duty at S1 rating.

Machine tools

• – higher speed 2-pole and 4-pole versions for spindle and feed drives.

Compressors

• – mid-range output with high starting torque requirement.

Conveying machinery

• – 6-pole and 8-pole versions for slow-speed drives.

HVAC and ventilation plant

• – where energy consumption is metered and reported.

Plant retrofit and efficiency upgrade programmes

• – replacing IE1 or IE2 motors on an existing IEC footprint.

OEM machinery builds

• – a single series covering 0.75 kW to 90 kW simplifies spare-part management.

Standards & Compliance

GB/T 28575-2020

• – technical specifications for the YE2 series (frame 80–280)

IEC 60034-30-1

• – IE3 efficiency class

IEC 60034-2-1

• – methods for determining losses and efficiency

IEC 60072-1

• – mounting dimensions and power ratings

GB 18613

• – minimum allowable values of energy efficiency and energy efficiency grades for small and medium three-phase asynchronous motors

Ordering & Support

Efficiency-based selection:

• tell us the driven equipment, running hours per year, required output and speed, and we will confirm the frame and pole count that suits the duty.

Model-level data:

• full technical parameter tables covering current, efficiency, power factor, torque, noise and weight for every model.

Voltage and frequency options:

• 380 V as standard, with any voltage between 220 V and 760 V available on request.

Documentation:

• dimensional drawings and technical data for the selected frame available on request.

Retrofit review:

• comparison of the proposed YE2 motor against the existing motor's frame, shaft and baseplate dimensions.

Technical demo:

• request a technical demo and quotation through the enquiry form on this page.

FAQ

Q: What efficiency class is the YE2 three-phase induction motor?

A: YE2 motors are built to the IE3 efficiency class defined in IEC 60034-30-1 and comply with the applicable GB 18613 energy efficiency requirements. Efficiency is determined in accordance with IEC 60034-2-1.

Q: How much energy can a YE2 motor save compared with a standard motor?

A: Up to 15% lower energy consumption than an IE2-class standard motor. The actual saving depends on the specific model, its load profile and annual running hours, so the gain should be calculated against the technical parameter table for the frame you are considering.

Q: Why does efficiency vary so much across the series?

A: Efficiency rises with frame size — 80.7% at 0.75 kW (2-pole) against 95.2% at the top of the 2-pole range. Pole count also matters: at equal output a 2-pole motor is generally more efficient than a 6-pole motor because losses per unit output are lower at higher speed. Choosing the right frame and pole count is therefore the largest single efficiency decision.

Q: Are YE2 motors suitable for continuous duty?

A: Yes. The series is rated S1 continuous duty, which is the duty type assumed in the efficiency figures and the application where IE3 motors deliver their fastest payback.

Q: Can a YE2 motor replace the existing motor on my machine?

A: Mounting dimensions and power ratings conform to IEC 60072-1, so a YE2 motor can replace an equivalent IEC-frame motor. Confirm the frame centre height, shaft dimensions, foot spacing and mounting code against your machine drawing before ordering — and where the replacement frame differs, check that the driven equipment tolerates the new speed.

Q: What is the temperature rise and insulation class?

A: The series uses Class F insulation with temperature rise evaluated at 80 K, giving a large thermal margin and long insulation life. Class H insulation is available on request.