GFCI

Features

  • High initial permeability, High output voltage, core size saving.
  • Low core loss, Good tolerance ability for large current impulse, Good protection of tripping of high current
  • High Curie temperature, Good temperature stability（-55℃~130℃)
  • Competitive price

Application

  • Electronic Leakage Circuit Breakers
  • Electromagnetic Leakage Circuit Breakers

Material Properties

Magnetic & Chemical Properties
Properties Measurement Unit 80% NiFe7
Permeability Permeability AC
Bs Tesla 0.751
Br Tesla 0.42
Hc 2(A.m)-1 Tesla 0.35
µ4 4 Tesla 550000
µ max Tesla 570000
Permeability AC
µ4z5 - 70000
µz86 - -
µmax - 95000
Core loss (W/Kg-1) 0.015
Chemical Composition
% Ni - 78%-81%
% Mo - 4.5%-6%
% Si - 0.05%-0.4%
% Mn - 0%-0.5%
% C - 0.01%
% Fe - Balance
Physical Properties
Density (g.cm -3) 8.7
Specific Heat (J.Kg-1.˚C-1) 460
Thermal conductivity W.m-1.˚C-1 19
Mean CTE between -50 & +200˚C ˚C-1 12.10-6
Electrical resistivity µΩ.cm 60
Curie Point ᵒC 420
Coefficient of magnetostriction at Saturation ∆l / l - 1-3 x 10-6
Melting temperature ᵒC 1450
Saturation Induction Tesla -
Hardness Hv 325
In Cold worked condition
UTS MPa 1050
0.2% PS(Cold Worked) MPa 1030
Elongation % min 3
In Annealed condition
Hardness Hv 160
UTS MPa 650
0.2% PS MPa 280
Elongation % 35
Grain Size - 8

KEY

  • Practical saturation measured for H = 800 A/m.
  • Remanent induction Br and coercive field Hc measured from H = 80 A/m.
  • Practical saturation Bs and Remanent induction Br measured for H = 800 A/m.
  • Measured for H = 4 mA/cm (peak value).
  • Sinusoidal excitation field H = 4 mA/cm (peak value).
  • Impedance permeability for B = 0.8 T.
  • Measurements made on 35X26X0.34 mm ring specimens after annealing in Pure & Dry Hydrogen for 4h at 1170°C followed by cooling at 200°C/h.
  • Practical saturation measured for H=5000A/m.
  • Core loss W/kg at 1.5T at 50Hz=3.90 max.
  • Typical operating frequency - 50 hz to 400hz

Product model and their tolerances

DIMENSIONS AND TOLERANCE
Outer Diameter (mm) Tolerance (mm) Inner Diameter (mm) Tolerance (mm) Height Tolerance (mm)
< 10 ± 0.4 < 10 ± 0.3 ± 0.3
< 25 ± 0.5 < 25 ± 0.4 ± 0.4
< 50 ± 1.0 < 50 ± 0.5 ± 0.5
< 80 ± 1.25 < 80 ± 0.75 ± 0.8
< 100 ± 1.5 < 100 ± 0.8 ± 0.8
< 160 ± 2.0 < 160 ± 1.3 ± 1.5
< 200 ± 2.5 < 200 ± 1.5 ± 1.5
< 320 ± 2.5 < 320 ± 2.0 ± 2.0
NOTE: General Cutting gap tolerance will be ± 0.5mm

Applications

Current measurement for:
  • Automotive
  • Aerospace
  • Medical
  • Renewable energy

Testing

As a standard practice PML checks Toroidal core (before cutting) for magnetic properties by tracing the B-H properties of the core itself. Below are results of a sample core

Sample Core Geometry
  • Outer Diameter - 160 mm+/-2mm
  • Inner Diameter - 110 mm+/-1mm
  • Height - 30 mm+0.2 /- 0.0 mm
GFCI Core Loop Plotter
Ind Pk(T) Permeability Loss/kg (Wt) H EffPk (A/cm) H RMS (A/cm) Ind RMS (T) Hc (A/cm) Br (T)
0.1 127150.24 0 0.0083 0.0059 0.0672 0.0019 0.02
0.2 144038.48 0 0.0134 0.0095 0.1378 0.0073 0.0868
0.3 158385.11 0 0.0188 0.0133 0.2102 0.0125 0.1708
0.4 164657.89 0 0.0242 0.0171 0.277 0.0166 0.2839
0.5 115868.36 0.0061 0.1674 0.1183 0.352 0.0204 0.3449
0.6 41492.51 0.015 0.3746 0.2649 0.4307 0.024 0.3815
0.636 14717.2 0.0183 0.4492 0.3176 0.4591 0.0253 0.3947