Microwave Journal

TDK's new EPCOS large-diameter inrush current limiters for high-watt applications

July 12, 2016

TDK Corp. presents the P27 series of EPCOS NTC inrush current limiters (ICLs) with a nominal disk diameter of 27 mm and lead spacing of 7.5 mm, thus extending the portfolio of large NTC ICLs for industrial electronics applications. The high material density of the new NTC ICLs enables a volume-efficient, high-performance design with a disk thickness of just ≤7 mm. The new P27 series with the ordering code B57127P0*M301 features extremely stable and reliable electrical characteristics. It offers a rated resistance of 0.5 Ω to 10 Ω at 25 °C and can handle high currents of up to 30 A, depending on type.

Thanks to their very low resistance in the operating state, NTC ICLs offer very low power dissipation in both AC and DC circuits. The large-diameter components of the new P27 series are especially suitable for use in large electric motors and drives and all kinds of high-watt power supplies as well as in industrial applications such as welding and plasma cutting equipment.

The coating material of the P27 series of ICLs is flame retardant and UL 94 V-0 approved. The new components are RoHS-compatible and UL approved (E69802). Samples of the P27 series are available.

Main applications

  • Large electric motors and drives and all kinds of high watt power supplies
  • Welding and plasma cutting equipment

Main features and benefits

  • High material density for a volume-efficient, high-performance design with a disk thickness of just ≤7 mm
  • Extremely stable electrical characteristics
  • Flame-retardant coating (UL 94 V-0)
  • UL approval (E69802)
  • RoHS-compatible

Key data

Type Nominal 
High current 
(Itest) *
(Imax) **
at 25°C 
at Itest 
(Rmin) [Ω]
B57127P0508M301 27 7.5 30 24 0.5 0.011
B57127P0109M301 27 7.5 30 22 1 0.013
B57127P0209M301 27 7.5 23 16 2 0.022
B57127P0509M301 27 7.5 20 12 5 0.033
B57127P0709M301 27 7.5 17 11 7 0.045
B57127P0100M301 27 7.5 15 9 10 0.053

* 50 hours at 25 °C
** 1000 hours according to IEC 60539-1

Further information on the products can be found under www.epcos.com/ntc_icl