BigAMP Datasheet

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.


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

***Data Sheets for bigAMP Inrush Current Limiters Below***


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.



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

  • Use the maximum allowable surge current and Ohm’s Law to determine the least allowable resistance at turn on for your application
  • Using the formula J = .5CV^2, determine how much input energy the thermistor will absorb when the device is turned on
  • Determine the maximum steady state current that will flow through the bigAMP Inrush Current Limiter
  • Select the bigAMP Inrush Current Limiter that will work for your application
Part Number (PDF) UL CSA Resistance @ 25 °C SSI Max Joules Max Max Cap 120 VAC Max Cap 240 VAC D Max (mm) T Nom (mm) Digi-Key Mouser
SL32 0R230 UL 0.3 100 30 6,946 1,736 31 6.0 570-1393-ND 995-SL32-0R230
SL32 0R530 CSA 0.5 150 30 10,419 2,604 31 5.0 570-1056-ND 995-SL32-0R530
SL32 0R536 CSA 0.5 150 36 17,366 4,341 31 5.0 570-1057-ND 995-SL32-0R536
SL32 1R030 UL CSA 1.0 160 30 11,114 2,778 31 5.0 570-1059-ND 995-SL32-1R030
SL32 1R036 CSA 1.0 160 36 11,114 2,778 31 6.0 570-1060-ND 995-SL32-1R036
SL32 2R023 UL CSA 2.0 250 23 17,366 4,341 31 6.0 570-1061-ND 995-SL32-2R023
SL32 2R025 UL CSA 2.0 250 25 20,839 5,209 31 7.0 570-1062-ND 995-SL32-2R025
SL32 4R023 UL 4.0 200 23 13,893 3,473 31 6.3 570-1063-ND 995-SL32-4R023
SL32 5R020 UL CSA 5.0 200 20 13,893 3,473 31 6.0 570-1064-ND 995-SL32-5R020
SL32 10015 UL CSA 10.0 150 15 10,419 2,604 31 6.0 570-1058-ND 995-SL32-10015