Motor slot wedge insulation materials classification and application

I. Classification of Motor Slot Wedge Insulation Materials Slot wedge insulation materials are generally classified ...

I. Classification of Motor Slot Wedge Insulation Materials

Slot wedge insulation materials are generally classified based on material composition, thermal class, and processing method:

1. Epoxy Glass Fiber Laminates

Material	Thermal Class	Characteristics	Applications
G10	Class F (155℃)	High insulation, excellent mechanical strength, moisture-resistant	General industrial motors, medium-voltage motors
G11	Class H (180℃)	High temperature resistance, excellent creep resistance	High-voltage motors, VFD motors, wind turbines
FR4	Class F	Flame-retardant, stable electrical properties	Fire-protected equipment, rail traction motors

2. Phenolic Laminates

Material	Thermal Class	Characteristics	Applications
Phenolic Paper Board (PFCP)	Class A (105℃)	Low cost, easy to process	Small motors, household fan motors
Phenolic Cotton Cloth Board	Class B–F (130–155℃)	High mechanical strength, wear-resistant	High-speed motors, motors with mechanical vibration

3. Flexible Composite Insulation Materials

Material	Thermal Class	Characteristics	Applications
DMD	Class B–F	Flexible, good dielectric strength, tear-resistant	Used as auxiliary insulation with rigid wedges to protect coils
NMN	Class H	High temperature resistance, excellent electrical performance	High-frequency, high-temperature motors (e.g., inverter or servo motors)

4. Molded/Injection Materials (Thermoset or Thermoplastic)

Material	Thermal Class	Characteristics	Applications
Thermoset Molding Materials	Class F–H	Injection-molded, consistent dimensions	Automated production lines, mass-produced standard motors
High-Performance Plastics (PPS, PI, PEEK)	Class H–C	Ultra-high temperature resistance, chemically stable	Specialty motors, military/aerospace, high-speed motors

II. Typical Applications & Recommended Materials

Application Scenario	Operating Conditions	Recommended Materials
Standard three-phase motors	Normal temperature, low voltage	G10, FR4, 3025
High-voltage or inverter-driven motors	High frequency, high electric field, high heat	G11, NMN, PI
Small household appliance motors	Cost-sensitive, large volume	PFCP, molded materials
Wind turbines, rail traction motors	Vibration, aging resistance, flame-retardant	Waved G11, FR4, DMD/NMN
Aerospace, military motors	High speed, high reliability, high thermal class	PI, PEEK, high-density G11

III. Material Selection Tips

Selection Factor	Recommendation
Thermal Class	Ensure the material rating meets or exceeds the motor insulation class
Mechanical Strength	Prefer G11 or 3025 for high-speed or high-load motors
Electrical Performance	Choose NMN or PI for high-frequency/inverter-driven systems
Cost Efficiency	Use PFCP or molded plastics for high-volume production
Custom Shapes	For special slot wedge profiles, select moldable or composite structures