Axial Lead Battery Strap PTC 0ZSC Series 0ZSC Series RoHS 2 Compliant Application Rechargeable battery packs, Lithium cell and battery packs Product Features Low profile, Low resistance, High hold current, Solid state Operating (Hold Current) Range 1.9A - 7.3A Maximum Voltage 20VDC Temperature Range -40 to 85 Agency Approval TUV (Std. EN62319-1-1, Cert. R50102187) UL Recognized Component (Std. UL1434, File E305051) UL Conditions of Acceptability: 1. These devices have been investigated for use in safety circuits and are suitable as a limiting device. 2. These devices have been calibrated to limit the current to 8 amps within 5 seconds, per ANSI/NFPA 70, National Electrical Code. LEAD FREE = HALOGEN FREE = Electrical Characteristics (23 ) Resistance Tolerance Agency Approvals Hold Trip Max Time to Rated Max Typical Part Number Current Current Trip 5xIH Voltage Current Power Rmin Rmax R1max (Bulk) IH, A IT, A Seconds Vmax, Vdc Imax, A Pd, W Ohms Ohms Ohms A 0ZSC0190FF1E 1.9 3.9 5.0 20 100 1.2 0.039 0.072 0.102 Y Y B 0ZSC0260FF1E 2.6 5.8 5.0 20 100 2.5 0.020 0.042 0.063 Y Y C 0ZSC0380FF1E 3.8 8.3 5.0 20 100 2.5 0.013 0.026 0.037 Y Y D 0ZSC0450FF1E 4.5 8.9 5.0 20 100 2.5 0.011 0.020 0.028 Y Y E 0ZSC0550FF1E 5.5 10.5 5.0 20 100 2.8 0.009 0.016 0.022 Y Y F 0ZSC0600FF1E 6.0 11.7 5.0 20 100 2.8 0.007 0.014 0.019 Y Y G 0ZSC0730FF1E 7.3 14.1 5.0 20 100 3.3 0.006 0.012 0.015 Y Y IH Hold Current-maximum current at which the device will not trip in still air at 23. IT Trip current-minimum current at which the device will always trip in still air at 23. Imax Maximum fault current device can withstand without damage at rated voltage (Vmax). Vmax Maximum voltage device can withstand without damage at its rated current. Pd Typical power dissipated by device when in tripped state in 23 still air environment. Rmin Minimum device resistance at 23 . Rmax Maximum device resistance at 23. R1max Maximum device resistance at 23, 1 hour after initial device trip, or after being soldered to PCB in end application. Specifications subject to change without notice belfuse.com/circuit-protection2 / 4 Type 0ZSC Series PTCs Basic Theory of Operation / Tripped Resistance Explanation Fundamentally, a Bel PTC consists of a block of polymeric material containing conductive filler and bonded between two conductive, planar terminations. At currents below the device IHOLD rating, AND at temperatures below 100C, the PTC maintains a resistance value below its R1 MAX rating. As the device s temperature approaches 130C, either due to an increase in ambient temperature or a current exceeding its I TRIP rating, volumetric expansion of the filled polymer breaks apart the majority of conductive pathways across the terminals created by chain contact of adjacent filler particles or device resistance increases sharply by several orders of magnitude. At the much higher Tripped resistance, there is just enough leakage current to allow internal heating to hold the device in its tripped state (around 125C) until power is interrupted. Once power is removed, the PTC s core cools and contracts allowing conductive chains to reform and return the device to its low resistance state. The catalog data for each device specifies aTypical Powe value. This is the power required to exactly match the heat lost by the tripped device to its ambient surroundings at 23C. By Ohm s Law, power can be stated as: W = E 2/R. Thus the approximate resistance of a Tripped PTC can be determined by: R = E 2/W, where is the voltage appearing across the PTC (usually the supply s open circuit voltage), and is the Typical Power value for the particular PTC. Since the PPTC acts to maintain a constant internal temperature, its apparent resistance will change based upon applied voltage and, to a lesser degree, ambient conditions. Consider the following example.... A PTC with a Typical Power of 1 watt protecting a circuit using a 60V supply will demonstrate an apparent, tripped resistance of: R = 60 2/1 = 3,600 ohms This same tripped device when used to protect a 12V circuit would now present an apparent resistance of: R = 12 2/1 = 144 ohms The value for Typical Power istypica because any physical factors that affect heat loss (such as ambient temperature or air convection) will somewhat alter the level of power that the PTC needs to maintain its internal temperature. In short, PTCs do not exhibit a constant, quantifiable tripped resistance value. Type Time To Trip at 23 . Specifications subject to change without notice Bel Fuse Inc. +1 201.432.0463 206 Van Vorst Street Bel.US.CS belf.com Jersey City, NJ 07302 USA belfuse.com/circuit-protection 2019 Bel Fuse, Inc. Rev. 0ZSC Jan2019