BigAmp Inrush Current Limiters

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.
	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

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	R@ 25°c (ohms)	Max SSI (A)	Max Energy (j)	Actual Failure (j)	R @ Max SSI(A)	R @50% Max SSI(A)	DC (s)	TC (s)	Mat
SL32 0R230	0.25	30	100	200	0.008	0.018	45.4	194	A
SL32 0R530	0.5	30	150	295	0.011	0.058	45.4	194	B
SL32 OR536	0.5	36	250	495	0.009	0.058	45.4	194	B
SL32 1R030	0.2	30	160	270	0.014	0.048	45.4	245	C
SL32 1R036	1.0	36	160	270	0.009	0.028	45.4	245	C
SL32 2R023	2.0	23	250	495	0.022	0.068	80	194	G
SL32 2R025	2.0	25	300	548	0.024	0.055	45.4	194	G
SL32 4R023	4.0	23	200	448	0.02	0.065	65.4	208	G
SL32 5R020	5.0	20	200	300	0.034	0.082	45.4	194	H
SL32 10015	10.0	15	265	220	0.048	0.108	45.4	232	I

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:

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.