Ametherm’s bigAMP Inrush Current Limiters are specially designed thermistors able to withstand up to 36 amperes of continuous current and 260 joules of input energy.
Inrush Current Limiters for high current applications

The bigAMP Inrush Current Limiter is useful in:

  • Switching Power Supplies
  • AC Motors
  • Uninterruptible Power Supplies
  • Variable Frequency Drive
  • Other equipment that can be improved with inrush current protection
BigAmp Inrush Current Limiters
DTLead DiameterSL
32 mm Max6.0 mm Max1.0 mm Nom7.9 mm Nom38.0 mm MinStraight Leads
Max cap
120 vac
Max cap
240 vac
D Max
T Nom
SL32 0R230Y0.3301006,9461,736316995-SL32-0R230
SL32 0R530Y0.53015010,4192,604315570-1056-ND995-SL32-0R5309008284
SL32 0R536Y0.53615017,3664,341315570-1057-ND995-SL32-0R5369008284
SL32 1R030YY1.03016011,1142,778315570-1059-ND995-SL32-1R0309008306
SL32 1R036Y1.03616011,1142,778316570-1060-ND995-SL32-1R0361653461
SL32 2R023YY2.02325017,3664,341316570-1061-ND995-SL32-2R0239008330
SL32 2R025YY2.02530020,8395,209316570-1062-ND995-SL32-2R0259008349
SL32 4R023Y4.02320013,8933,473316570-1063-ND995-SL32-4R023
SL32 5R020YY5.02020013,8933,473316570-1064-ND995-SL32-5R0209008365
SL32 10015YY10.01515010,4192,604316570-1058-ND995-SL32-100159008322


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How Does the bigAMP Inrush Current Limiter Work?

The bigAMP Inrush Current Limiter absorbs high amounts of inrush current when electrical equipment is turned on by offering a high resistance to current and quickly decreasing in resistance once steady state current begins to flow through the thermistor.

In a switching power supply, the instantaneous surge energy is caused by the large input filter capacitors and AC input voltage.

During the absorption of energy, the initial high resistance of the thermistor drops within milliseconds to a negligible resistance in preparation of allowing high levels steady state current to flow with a minimal loss of power through the circuit.

The bigAMP Inrush Current Limiter will absorb up to 260 joules of input energy and carry 36 amperes of steady state current.


How to specify the right bigAMP Inrush Current Limiter for your application:

  1. Use the maximum allowable surge current and Ohm’s Law to determine the least allowable resistance at turn on for your application
  2. Using the formula J = .5CV^2, determine how much input energy the thermistor will absorb when the device is turned on
  3. Determine the maximum steady state current that will flow through the bigAMP Inrush Current Limiter
  4. Select the bigAMP Inrush Current Limiter that will work for your application


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