Reliability data

Test

Standard

Test conditions

∆R

(typical)

Remarks

Storage in

dry heat

IEC

60068-2-2

Storage at upper

category temperature

T: 170

°C

t: 1000 h

< 10%

No visible

damage

Storage in damp

heat, steady state

IEC

60068-2-78

Temperature of air: 40

°C

Relative humidity of air: 93%

Duration: 21 days

< 5%

No visible

damage

Rapid temperature

cycling

IEC

60068-2-14

Lower test temperature:

55

°C

Upper test temperature: 170

°C

Number of cycles: 10

< 10%

No visible

damage

Endurance

t: 1000 h

< 10%

No visible

damage

Cyclic

endurance

On-time = 1 min

Cooling time = 6 min

< 10%

No visible

damage

Transient

load

Number of cycles: 1000

< 5%

No visible

damage

Note

The self-heating of a thermistor during operation depends on the load applied and the

applicable dissipation factor.

When loaded with maximum allowable current/power and the specified dissipation factor is

taken as a basis, the NTC thermistor may reach a mean temperature of up to 250

°C.

The heat developed during operation will also be dissipated through the lead wires. So the

contact areas, too, may become quite hot at maximum load.

When mounting NTC thermistors you have to ensure that there is an adequate distance

between the thermistor and all parts which are sensitive to heat or combustible.

Inrush current limiters

B57237

ICLs

S237

Page 3 of 15

Please read Cautions and warnings and

Important notes at the end of this document.