EFOLIT® Taped High Frequency Litz Wires


The EFOLIT product family represents a triple insulated taped litz wire design with VDE-certification for reinforced insulation, which is necessary to certify products for high voltage applications. Litz wire diameters up to 5.0 mm with temperature class F/155°C and H/180°C cover a wide range of operating temperatures for various power applications.

According to specification:

DIN EN 60950, annex U
DIN EN 62368, annex J
DIN EN 61558, annex K
DIN EN 60601, annex L

Features and benefits of EFOLIT® - litz wires

Constructions with self adhesive sPET, sPEN tape material allow very high break down voltages as well as high copper filling factor and flexibility. The requested long term high working voltage resistivity requires a very precise taping process assuring very small tolerances within one spool, one lot and different shipments. EFOLIT®-winding wires are optimized for high safety demands of coil constructions without or with reduced intermediate tape insulation, usually used for transformer designs aiming at simplified winding processes and reduction of dimension, weight and material.

Technical properties of EFOLIT® - litz wires

Operating range

Winding wires for reinforced insulation
Max. rated and peak voltage 1000 Vrms
1414 Vpeak
Max. frequency 500 kHz
Temperature class F / 155 °C
H / 180 °C

Technical data of taping material

Self-adhesive tape sPET sPEN
Description Polyester Polyethylene Naphtalate
Permittivity (JIS C 2318) 3.2 2.9
Tape - UL file no. E 515235 E 515235
Processing Fusible Fusible

Product identification

Validated standards Code sPET sPEN
IEC/DIN EN 61558, 60950, 62368, 60601
VDE-Reg. no. E078
(nom. test voltage: 6 kV)
EFOLIT 11F Class F with enamel type
TI = 155°C / 311°F
EFOLIT 22H - Class H with enamel type
TI = 180°C / 356°F
IEC/DIN EN 60950, 62368
VDE-Reg. no. E450
(nom. test voltage: 3 kV)
EFOLIT 13F * Class F with enamel type
TI = 155°C / 311°F
EFOLIT 24H * - Class H with enamel type
TI = 180°C / 356°F

TI = Temperature Index
* Also certified as basic insulation acc. IEC/DIN EN 61558, Annex K

Dimensional range

Diameter single conductor 0.030 - 0.300 mm
48 - 28 AWG
Total conductor cross section 0.100 - 10.600 mm2
Outer diameter litz wire (approx.) 0.500 - 5.000 mm
24 - 4 AWG
Tape insulation (min.) 3 layers


  • EV (Electric Vehicles)
  • OBC (Onboard charger)
  • DC/DC converter
  • Wireless charging
  • Charging piles
  • SMPS (Switch Mode Power Supplies)
  • HF transformers
  • HF transducers
  • HF chokes