YEJ Series Electromagnetic Brake Three-Phase Asynchronous Motors: Complete Technical Guide

1. Introduction

The YEJ series electromagnetic brake three-phase asynchronous motor is an integrated electromechanical system that combines a standard squirrel-cage induction motor with a DC electromagnetic disc brake assembly. Designed per IEC 60034 and JB/T6456 standards, these motors deliver instantaneous braking capability upon power loss, making them indispensable for applications demanding rapid stopping, precise positioning, and load-holding security.

Unlike conventional induction motors that rely on external mechanical brakes or regenerative braking systems, the YEJ series integrates the braking mechanism directly onto the motor’s non-drive end (NDE). This unified architecture eliminates coupling alignment issues, reduces installation footprint, and ensures synchronous braking response across the entire drivetrain.

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2. Construction & Operating Principle

2.1 Structural Overview

The YEJ motor consists of two primary subsystems:

表格

Component	Material / Specification	Function
Motor Housing	Die-cast aluminum (H63–H132) / Cast iron (H160–H280)	Structural rigidity, heat dissipation
Stator Core	Silicon steel DW470/DW600 (0.5 mm laminations)	Magnetic flux path, eddy current reduction
Rotor	Squirrel-cage aluminum die-cast	Electromechanical energy conversion
Winding Wire	QZ-2/155 or QZ-2/180 (Class F/H)	Thermal endurance, dielectric strength
Brake Coil	DC-excited electromagnetic winding	Generates braking force upon de-energization
Friction Disc	Composite friction material (non-asbestos)	Torque transmission during braking
Armature Plate	Steel with surface treatment	Magnetic attraction surface
Brake Spring	Alloy steel, pre-compressed	Applies mechanical braking force
Manual Release	Hand-lever mechanism	Emergency/manual brake disengagement

2.2 Electromagnetic Braking Mechanism

The braking action operates on the fail-safe principle (power-off braking):

Energized State (Motor Running): When AC power is applied to the motor and the rectified DC voltage energizes the brake coil, the electromagnetic force Fem​ overcomes the spring force Fspring​ :

Fem​=2μ0​B2A​>Fspring​

Where:

• B = Magnetic flux density in the air gap (T)
• A = Pole face area (m²)
• μ0​ = Permeability of free space (4π×10−7 H/m)

The armature plate is attracted toward the coil housing, compressing the brake spring and releasing the friction disc. The motor shaft rotates freely.

De-energized State (Braking): Upon power interruption, the electromagnetic field collapses exponentially:

B(t)=B0​e−t/τ

Where the time constant τ=L/R (coil inductance / resistance). Once Fem​<Fspring​ , the spring forces the armature plate against the friction disc, generating braking torque Tb​ :

Tb​=n⋅μ⋅Fspring​⋅reff​

Where:

• n = Number of friction surfaces
• μ = Coefficient of friction (typically 0.35–0.45 for composite materials)
• reff​ = Effective friction radius (m)

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3. Technical Specifications

3.1 Motor Electrical Parameters

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

表格

Model	Power (kW)	Speed (r/min)	Efficiency (%)	Power Factor	Current (A)	Rated Torque (Nm)	Locked-Rotor Torque / Tn​	Max Torque / Tn​	Static Brake Torque (Nm)	No-Load Braking Time (s)
YEJ-801-2	0.75	2,825	75.0	0.84	1.8	2.54	2.2	2.3	7.5	0.10
YEJ-802-2	1.1	2,825	77.0	0.86	2.5	3.72	2.2	2.3	7.5	0.10
YEJ-90S-2	1.5	2,840	78.0	0.85	3.4	5.04	2.2	2.3	15	0.15
YEJ-90L-2	2.2	2,840	80.5	0.86	4.8	7.40	2.2	2.3	15	0.15
YEJ-100L-2	3	2,880	82.0	0.87	6.4	10.0	2.2	2.3	30	0.15
YEJ-112M-2	4	2,890	85.5	0.87	8.2	13.2	2.2	2.3	40	0.15
YEJ-132S1-2	5.5	2,900	85.5	0.88	11.1	18.1	2.0	2.3	80	0.15
YEJ-132S2-2	7.5	2,900	86.2	0.88	15.0	24.7	2.0	2.3	80	0.15
YEJ-160M1-2	11	2,930	87.2	0.88	21.8	35.9	2.0	2.3	150	0.30
YEJ-160M2-2	15	2,930	88.2	0.88	29.4	48.9	2.0	2.2	150	0.30
YEJ-160L-2	18.5	2,930	89.0	0.89	35.5	60.3	2.0	2.2	150	0.30
YEJ-180M-2	22	2,940	89.0	0.89	42.2	71.5	2.0	2.2	200	0.30
YEJ-200L1-2	30	2,950	90.0	0.89	56.9	97.1	2.0	2.2	300	0.45
YEJ-200L2-2	37	2,950	90.5	0.89	69.8	119.8	2.0	2.2	300	0.45
YEJ-225M-2	45	2,970	91.5	0.89	84.0	144.7	2.0	2.2	450	0.45

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

表格

Model	Power (kW)	Speed (r/min)	Efficiency (%)	Power Factor	Current (A)	Rated Torque (Nm)	Locked-Rotor Torque / Tn​	Max Torque / Tn​	Static Brake Torque (Nm)	No-Load Braking Time (s)
YEJ-801-4	0.55	1,405	71.0	0.75	1.57	3.74	2.2	2.4	7.5	0.10
YEJ-802-4	0.75	1,405	73.0	0.76	2.02	5.10	2.2	2.4	7.5	0.10
YEJ-90S-4	1.1	1,445	75.0	0.77	2.82	7.27	2.2	2.3	15	0.15
YEJ-90L-4	1.5	1,445	78.0	0.79	3.70	9.91	2.2	2.3	15	0.15
YEJ-100L1-4	2.2	1,440	80.0	0.81	5.16	14.6	2.2	2.3	30	0.15
YEJ-100L2-4	3	1,440	82.0	0.82	6.78	19.9	2.2	2.3	30	0.15
YEJ-112M-4	4	1,440	84.0	0.82	8.82	26.5	2.2	2.3	40	0.15
YEJ-132S1-4	5.5	1,440	85.0	0.83	11.7	36.5	2.2	2.3	80	0.15
YEJ-132S2-4	7.5	1,440	87.0	0.84	15.6	49.7	2.2	2.3	80	0.15
YEJ-160M1-4	11	1,450	88.0	0.85	21.3	72.5	2.2	2.2	150	0.30
YEJ-160M2-4	15	1,450	89.0	0.85	30.1	98.8	2.2	2.2	150	0.30
YEJ-180M-4	18.5	1,455	90.5	0.86	36.5	121.5	2.2	2.2	150	0.30
YEJ-180L-4	22	1,455	91.0	0.86	43.1	144.4	2.0	2.2	200	0.30

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

表格

Model	Power (kW)	Speed (r/min)	Efficiency (%)	Power Factor	Current (A)	Rated Torque (Nm)	Locked-Rotor Torque / Tn​	Max Torque / Tn​	Static Brake Torque (Nm)	No-Load Braking Time (s)
YEJ-90S-6	0.75	910	72.5	0.70	2.3	7.87	2.0	2.2	15	0.15
YEJ-90L-6	1.1	910	73.5	0.72	3.2	11.5	2.0	2.2	15	0.15
YEJ-100L-6	1.5	940	77.5	0.74	4.0	15.2	2.0	2.2	30	0.15
YEJ-112M-6	2.2	960	80.5	0.74	5.6	21.9	2.0	2.1	40	0.15
YEJ-132S-6	3	960	83.5	0.76	7.2	29.8	2.0	2.2	80	0.15
YEJ-132M1-6	4	960	84.0	0.77	9.4	39.8	2.0	2.2	80	0.15
YEJ-132M2-6	5.5	960	85.3	0.78	12.6	54.7	2.0	2.0	150	0.30
YEJ-160M-6	7.5	970	86.0	0.78	17.0	73.8	2.0	2.1	150	0.30
YEJ-160L-6	11	970	87.0	0.78	24.6	108.3	2.0	2.1	150	0.30
YEJ-180L-6	15	970	89.5	0.81	31.4	147.6	1.8	2.0	200	0.30
YEJ-200L1-6	18.5	980	89.8	0.83	37.7	180.3	1.8	2.0	300	0.45
YEJ-200L2-6	22	980	90.2	0.86	44.6	214.4	1.8	2.0	300	0.45
YEJ-225M-6	30	980	90.2	0.85	59.3	292.4	1.7	2.0	450	0.45

3.2 Brake Technical Parameters

表格

Frame Size	Armature Stroke (mm)	No-Load Braking Time (s)	Static Braking Torque (Nm)	Excitation Voltage (V DC)	Excitation Power (W)
YEJ-63	—	0.10	3.5	99	35
YEJ-71	—	0.10	4.0	99	40
YEJ-80	1.0	0.20	7.5	99	50
YEJ-90	1.0	0.20	15	99	60
YEJ-100	1.0	0.20	30	99	80
YEJ-112	1.0	0.25	40	170	110
YEJ-132	1.2	0.25	75	170	130
YEJ-160	1.2	0.35	150	170	150
YEJ-180	1.2	0.35	200	170	150
YEJ-200	1.5	0.45	300	170	200
YEJ-225	1.5	0.45	450	170	200

3.3 Braking Performance Analysis

The braking time tb​ under load conditions depends on the moment of inertia J and the braking torque Tb​ :

tb​=Tb​−Tload​J⋅ω0​​

Where:

• J = Total moment of inertia (motor + load) (kg·m²)
• ω0​ = Initial angular velocity (rad/s)
• Tload​ = Load torque during braking (Nm)

For no-load braking (where Tload​≈0 ):

tb0​=Tb​Jmotor​⋅ω0​​

The braking torque ratiokb​ is a critical selection parameter:

kb​=Tn​Tb​​×100%

表格

Frame Size	Rated Torque Range (Nm)	Brake Torque (Nm)	kb​ Range (%)
YEJ-80	2.5–5.1	7.5	150–300
YEJ-90	5.0–11.5	15	130–300
YEJ-100	10.0–19.9	30	150–300
YEJ-112	13.2–26.5	40	150–300
YEJ-132	18.1–54.7	75	137–415
YEJ-160	35.9–108.3	150	138–418
YEJ-180	71.5–147.6	200	135–280
YEJ-200	97.1–214.4	300	140–309
YEJ-225	144.7–292.4	450	154–311

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4. Model Nomenclature System

plain

YEJ □□□ □ - □ - □
│   │   │   │   └── 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 + EJ = Electromagnetic Brake)

Example: YEJ-132M2-4-B5

• YEJ: Electromagnetic brake motor series
• 132: Center height = 132 mm
• M2: Medium frame, second core length
• 4: 4-pole (1,500 r/min synchronous)
• B5: Flange mounting (large flange)

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5. Standard Operating Conditions

表格

Parameter	Specification
Rated Voltage	380 V (3-phase), 50 Hz / 60 Hz on request
Power Range	0.12 kW – 45 kW (0.16 HP – 60 HP)
Frame Size	H63 – H280 (IEC 60072)
Pole Number	2, 4, 6, 8 poles
Protection Class	IP54 / IP55 / IP56 (IEC 60034-5)
Insulation Class	Class F (155°C) standard; Class H (180°C) optional
Cooling Method	IC411 (Totally Enclosed Fan-Cooled)
Duty Type	S1 (Continuous Duty); S3, S4 available on request
Connection	Star (Y) for ≤ 3 kW; Delta (Δ) for ≥ 4 kW
Ambient Temperature	-15°C to +40°C
Altitude	≤ 1,000 m
Relative Humidity	≤ 90%
Brake Rectifier	Built-in, AC220V→DC99V (≤3kW); AC380V→DC170V (≥4kW)

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6. Dimensional & Mounting Data

6.1 Foot-Mounted (B3) Dimensions

表格

Frame	A	B	C	D	E	F	G	H	K	L
63	100	80	40	⌀11	23	4	12.5	63	⌀7	270
71	112	90	45	⌀14	30	5	16	71	⌀7	315
80	125	100	50	⌀19	40	6	21.5	80	⌀10	340
90S	140	100	56	⌀24	50	8	21	90	⌀10	400
90L	140	125	56	⌀24	50	8	27	90	⌀10	400
100L	160	140	63	⌀28	60	8	31	100	⌀12	440
112M	190	140	70	⌀28	60	8	31	112	⌀12	480
132S	216	140	89	⌀38	80	10	41	132	⌀12	567
132M	216	178	89	⌀38	80	10	41	132	⌀12	567
160M	254	210	108	⌀42	110	12	45	160	⌀14.5	700
160L	254	254	108	⌀42	110	12	45	160	⌀14.5	780
180M	279	241	121	⌀48	110	14	51.5	180	⌀14.5	880
180L	279	279	121	⌀48	110	14	51.5	180	⌀14.5	880

Note: L dimension includes brake assembly overhang (typically +30–80 mm vs. standard Y-series). All dimensions in mm.

6.2 Flange-Mounted (B5) Dimensions

表格

Frame	D	E	F	G	M	N	P	S	T	L
63	⌀11	23	4	12.5	115	95	140	10	3.0	280
71	⌀14	30	5	16	130	110	160	10	3.0	315
80	⌀19	40	6	21.5	165	130	200	12	3.5	340
90S/L	⌀24	50	8	27	165	130	200	12	3.5	400
100L	⌀28	60	8	31	215	180	250	14.5	4	440
112M	⌀28	60	8	31	215	180	250	14.5	4	480
132S/M	⌀38	80	10	41	265	230	300	14.5	4	567
160M/L	⌀42	110	12	45	300	250	350	18.5	5	780
180M/L	⌀48	110	14	51.5	300	250	350	18.5	5	880

6.3 Mounting Configuration Availability

表格

Mounting Code	Description	H63–H112	H132–H160	H180–H225
B3	Foot-mounted, horizontal	✓	✓	✓
B5	Flange-mounted, large flange	✓	✓	✓
B14	Flange-mounted, small flange	✓	✓	—
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. Application Engineering

7.1 Industry Deployment Matrix

表格

Industry	Application	Critical Requirement	Recommended YEJ Spec
Machine Tools	CNC lathe spindle, milling head	Rapid stop for tool change	4-pole, kb​ ≥ 150%
Material Handling	Overhead cranes, hoists	Load holding, anti-drop	6-pole, kb​ ≥ 200%
Packaging	Carton sealers, palletizers	Precise indexing	4-pole, braking time ≤ 0.2s
Textile	Warping machines, looms	Tension control, quick stop	4-pole, Class F insulation
Printing	Offset presses, die-cutters	Registration accuracy	4-pole, low backlash coupling
Food & Beverage	Conveyors, mixers	Hygienic design, washdown	IP55, aluminum housing
Construction	Hoists, winches, gates	Safety braking, outdoor duty	IP55, cast iron frame
Woodworking	Saws, planers, sanders	Emergency stop compliance	2-pole, kb​ ≥ 200%
Automotive	Assembly line conveyors	High cycle rate	S3 duty, 60% CDF
Agriculture	Grain elevators, dryers	Dust protection	IP55, sealed bearings

7.2 Braking Energy Dissipation

During each braking event, the kinetic energy of the rotating system is converted to heat at the friction interface:

Ebrake​=21​Jω02​+21​Iload​ω02​

The heat flux densityq at the friction surface:

q=Af​⋅tb​Ebrake​​

Where Af​ = friction surface area (m²).

For high-cycle applications (S3 duty), the thermal capacity must be verified:

Qcycle​=Ebrake​⋅ncycles​≤Qmax​

Where ncycles​ = cycles per hour, Qmax​ = maximum permissible thermal load (manufacturer-specified).

7.3 Duty Cycle Derating

For S3 intermittent periodic duty, the equivalent thermal current is:

Ieq​=Irated​tcycle​ton​​​

Where:

• ton​ = operating time per cycle
• tcycle​ = total cycle time
• CDF (Cyclic Duration Factor) = ton​/tcycle​×100%

Standard CDF ratings: 15%, 25%, 40%, 60%

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8. Comparative Analysis: YEJ vs. External Brake Systems

表格

Evaluation Criteria	YEJ Integrated Brake	Motor + External Brake	Servo Motor + Drive
Installation Footprint	Compact (single unit)	Large (motor + brake + coupling)	Moderate
Shaft Alignment	Perfect (common shaft)	Requires precision alignment	Perfect
Braking Response Time	0.10–0.45 s	0.15–0.60 s (with coupling backlash)	< 0.05 s
Holding Torque	130–400% Tn​	Configurable	100–300% Tn​
Fail-Safe Operation	Yes (spring-applied)	Yes (if spring-applied type)	No (requires power)
Maintenance Points	1 (integrated)	3+ (motor, coupling, brake)	2+ (motor, encoder)
Initial Cost	Low–Moderate	Moderate	High
Energy Consumption	Low (brake coil only)	Low	High (servo drive losses)
Positioning Accuracy	±0.5–2°	±0.5–2°	±0.01°
Environmental Tolerance	High (no electronics)	High	Moderate (sensitive to EMI)
Best Application	General machinery braking	Very high torque requirements	Precision servo positioning

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9. Installation & Commissioning

9.1 Electrical Connection Diagram

plain

    L1 ──┬── U (Motor)
    L2 ──┼── V (Motor)
    L3 ──┼── W (Motor)
         │
         ├── Rectifier Module ──┬── +DC (Brake Coil)
         │    (AC→DC)           └── −DC (Brake Coil)
         │
    PE ──┴── Ground

Voltage Conversion:

• Motors ≤ 3 kW: AC 220V single-phase → DC 99V
• Motors ≥ 4 kW: AC 380V (derived from L1-L2) → DC 170V

9.2 Air Gap Adjustment

The brake air gap δ must be maintained within specification for proper operation:

表格

Frame	Nominal Air Gap (mm)	Maximum Allowable (mm)	Adjustment Interval
YEJ-80	0.20	0.50	500,000 cycles
YEJ-90	0.20	0.50	500,000 cycles
YEJ-100	0.20	0.50	500,000 cycles
YEJ-112	0.25	0.60	500,000 cycles
YEJ-132	0.25	0.60	500,000 cycles
YEJ-160	0.35	0.80	1,000,000 cycles
YEJ-180	0.35	0.80	1,000,000 cycles
YEJ-200	0.45	1.00	1,000,000 cycles
YEJ-225	0.45	1.00	1,000,000 cycles

9.3 Pre-Commissioning Checklist

表格

Item	Check	Acceptance Criteria
1	Insulation resistance	≥ 100 MΩ at 500V DC
2	Brake coil resistance	Within ±10% of nameplate value
3	Air gap measurement	Within nominal specification
4	Manual release function	Smooth operation, full release
5	Rotation direction	Clockwise when viewed from DE
6	No-load current	≤ 40% of rated current
7	Braking time	Within catalog specification
8	Brake holding torque	≥ rated static torque

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10. Maintenance & Troubleshooting

10.1 Preventive Maintenance Schedule

表格

Interval	Component	Action	Indicator of Required Service
250 hours	Brake air gap	Measure and record	Increased braking time
1,000 hours	Friction disc	Visual inspection for wear	Brake torque reduction >10%
2,000 hours	Brake spring	Load test	Uneven braking, noise
5,000 hours	Bearings	Temperature check, vibration analysis	Temperature >80°C, vibration >4.5 mm/s
10,000 hours	Friction disc	Replace (typical life)	Wear approaching rivet heads
20,000 hours	Brake coil	Resistance test, insulation check	Resistance change >15%
Annually	Rectifier	Output voltage verification	DC voltage < 90% nominal
Annually	Full assembly	Comprehensive inspection	Any abnormal operational symptom

10.2 Common Faults & Remedies

表格

Symptom	Probable Cause	Corrective Action
Motor runs, brake remains engaged	Rectifier failure; coil open circuit	Test rectifier output; measure coil resistance
Excessive braking time	Worn friction disc; excessive air gap	Replace friction disc; adjust air gap
Brake noise during engagement	Contaminated friction surface; uneven wear	Clean with solvent; replace disc if uneven
Brake slips under load	Glazed friction surface; insufficient spring force	Resurface or replace disc; test spring force
Brake coil overheating	Incorrect voltage; continuous energization	Verify rectifier output; check duty cycle
Vibration during braking	Misalignment; worn bearings	Check coupling alignment; replace bearings
Intermittent brake release	Loose connections; failing rectifier	Tighten terminals; replace rectifier module

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11. Quality Assurance & Certifications

表格

Certification	Standard	Applicability
CE Marking	EU Machinery Directive 2006/42/EC	European market compliance
CCC	GB 18613 / GB 30253	China Compulsory Product Certification
ISO 9001	ISO 9001:2015	Quality management system
IEC	IEC 60034-1, IEC 60034-5, IEC 60034-30	International electrotechnical standards
EAC	TR CU 004/2011, TR CU 020/2011	Eurasian Customs Union
UL/cUL	UL 1004	North American market (optional)

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12. Selection Methodology

12.1 Step-by-Step Sizing Procedure

Step 1: Determine Load Requirements

• Calculate load torque: Tload​=ωshaft​Pload​​
• Determine required braking torque: Tbrake​≥1.5×Tload​
• Assess duty cycle and cycles per hour

Step 2: Select Motor Power

• Required motor power: Pmotor​=9550×ηdrive​Tload​×n​
• Apply service factor (typically 1.15–1.25 for brake motors)

Step 3: Verify Braking Performance

• Check braking torque ratio kb​≥150%
• Verify braking time meets process requirements
• Confirm thermal capacity for cyclic duty

Step 4: Confirm Environmental Compatibility

• Ambient temperature range
• Protection class (IP rating)
• Hazardous area classification (if applicable)

12.2 Application Example

Application: 5 kW overhead crane hoist

• Load torque: 48 Nm at 1,440 r/min
• Required braking torque: 48×1.5=72 Nm
• Duty: S3, 40% CDF, 120 cycles/hour

Selection: YEJ-132S2-4

• Rated power: 7.5 kW (service factor = 1.5)
• Rated torque: 49.7 Nm
• Brake torque: 80 Nm (kb​=161% )
• Braking time: 0.15 s (no-load)
• Estimated loaded braking time:

tb​=80−48(0.08+Jload​)×151​≈0.35 s

This meets typical hoist requirements (≤ 0.5 s).

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13. Conclusion

The YEJ series electromagnetic brake three-phase asynchronous motor represents a mature, cost-effective solution for applications requiring integrated braking capability. By combining a robust induction motor with a fail-safe DC electromagnetic brake in a single, compact package, the YEJ series eliminates the complexity, alignment challenges, and maintenance burden associated with external braking systems.

Key advantages for system designers and procurement professionals include:

• Fail-safe operation: Spring-applied braking ensures load holding during power failures
• Simplified mechanics: Single-shaft design eliminates coupling backlash and alignment issues
• Rapid response: Braking times from 0.10 to 0.45 seconds depending on frame size
• High torque margin: Static braking torque ranging from 130% to 400% of rated motor torque
• Broad applicability: Frame sizes from H63 to H280, power range 0.12–45 kW
• Low total cost of ownership: Minimal maintenance, long friction disc life, integrated rectifier

For applications in material handling, machine tools, packaging, and general industrial machinery where safety, reliability, and rapid stopping are non-negotiable, the YEJ series delivers proven performance at a fraction of the cost of servo-based alternatives.

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All technical data conforms to IEC 60034 series standards and JB/T6456 industry specifications. For specialized applications involving high cycle rates, extreme environments, or precise positioning requirements, consult factory application engineering for customized solutions.