Motor Insulation Paper Selection Quick Reference

Motor Insulation Paper Selection Quick Reference Applicable to industrial motors, generators, inverter-duty motors, ...

Motor Insulation Paper Selection Quick Reference

Applicable to industrial motors, generators, inverter-duty motors, and new energy / EV drive motors

I. Quick Selection by Motor Component

Motor Component	Recommended Insulation Paper	Thermal Class	Typical Thickness	Application Notes
Stator Slot Liner	DMD	B / F	0.18–0.30 mm	Mainstream choice for low-voltage motors, cost-effective
Stator Slot Liner (High Temperature)	NMN	F / H	0.20–0.35 mm	Inverter-driven and high-temperature applications
Stator Slot Liner (High-End)	NHN	H / C	0.20–0.35 mm	High-speed and EV motors
Phase-to-Phase Insulation	DMD / Aramid Paper	F / H	0.18–0.25 mm	Prevents phase short circuits
Inter-layer Winding Insulation	DMD / PET	B / F	0.10–0.20 mm	Auxiliary insulation
End-Winding Wrapping	Aramid Paper	H	0.18–0.30 mm	Excellent thermal aging resistance
Medium & High Voltage Main Insulation	Mica Paper / Mica Tape	F / H	Customized	Motors ≥ 3 kV

II. Selection by Thermal Class

Thermal Class	Recommended Insulation Paper	Typical Applications
Class B (130°C)	DMD, PET	Standard low-voltage industrial motors
Class F (155°C)	DMD, NMN	Inverter-duty and heavy-load motors
Class H (180°C)	NMN, Aramid Paper, NHN	High-temperature and high-reliability motors
Class C (220°C)	NHN, PI-based systems	High-speed and new energy motors

III. Selection by Motor Type

Motor Type	Recommended Insulation Paper System	Notes
Low-Voltage Industrial Motors (≤1 kV)	DMD + PET	Cost-oriented design
Inverter-Duty Motors	NMN + Aramid Paper	Improved thermal aging resistance
Medium & High Voltage Motors (3–11 kV)	Mica Paper + Aramid Paper	VPI process required
Generators	NMN / Mica Paper	Long service life design
New Energy / EV Drive Motors	NHN / Aramid / PI	Partial discharge resistance

IV. Key Checkpoints for Selection (Procurement Checklist)

Thermal class ≥ motor design thermal class
Thickness tolerance and slot insertion stability
Compatibility with impregnation varnish / VPI processes
Batch consistency and long-term supply stability
Compliance with IEC / UL / RoHS / REACH
Tip: European customers usually prioritize material system stability and long-term reliability over the lowest price.

V. Manufacturer’s quotation

XUJUE ElECTRICAL is a professional manufacturer of high-quality electrical insulation materials with more than 65 years of manufacturing experience. The products have passed UL,RoHS,SGS,MSDS,CEMT testing and certification.

If you are looking for motor insulation paper, please contact Xujue Electrical and provide the product specifications, thickness and purpose you need, you can get detailed product information and quotation, and also send samples free of charge