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
  • Frequency Generators
  • Other equipment that can be improved with inrush current protection
BigAmp Inrush Current Limiters
D T Lead Diameter S L
32 mm Max 6.0 mm Max 1.0 mm Nom 7.9 mm Nom 38.0 mm Min Straight Leads
Part UL CSA R SSI
Max
Joules
Max
Max cap
120 vac
Max cap
240 vac
D Max
(mm)
T Nom
(mm)
Digikey Mouser Farnell
SL32 0R230 Y 0.3 30 100 6,946 1,736 31 6 995-SL32-0R230
SL32 0R530 Y 0.5 30 150 10,419 2,604 31 5 570-1056-ND 995-SL32-0R530 9008284
SL32 0R536 Y 0.5 36 150 17,366 4,341 31 5 570-1057-ND 995-SL32-0R536 9008284
SL32 1R030 Y Y 1.0 30 160 11,114 2,778 31 5 570-1059-ND 995-SL32-1R030 9008306
SL32 1R036 Y 1.0 36 160 11,114 2,778 31 6 570-1060-ND 995-SL32-1R036 1653461
SL32 2R023 Y Y 2.0 23 250 17,366 4,341 31 6 570-1061-ND 995-SL32-2R023 9008330
SL32 2R025 Y Y 2.0 25 300 20,839 5,209 31 6 570-1062-ND 995-SL32-2R025 9008349
SL32 4R023 Y 4.0 23 200 13,893 3,473 31 6 570-1063-ND 995-SL32-4R023
SL32 5R020 Y Y 5.0 20 200 13,893 3,473 31 6 570-1064-ND 995-SL32-5R020 9008365
SL32 10015 Y Y 10.0 15 150 10,419 2,604 31 6 570-1058-ND 995-SL32-10015 9008322

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.