Inrush current limiters
ICLs
B57236
S236
Mounting
When NTC thermistors are encapsulated with sealing material or overmolded with plastic
material, the precautions given in chapter “Mounting instructions”, “Sealing and potting” must
be observed.
Electrode must not be scratched before/during/after the mounting process.
Contacts and housings used for assembly with thermistor have to be clean before mounting.
During operation, the inrush current limiters surface temperature can be very high. Ensure that
adjacent components are placed at a sufficient distance from the thermistor to allow for proper
cooling of the thermistors.
Ensure that adjacent materials are designed for operation at temperatures comparable to the
surface temperature of the thermistor. Be sure that surrounding parts and materials can
withstand this temperature.
Make sure that inrush current limiters are adequately ventilated to avoid overheating.
Avoid contamination of thermistor surface during processing.
Operation
Use thermistors only within the specified operating temperature range.
Use inrush current limiters only within the specified voltage and current ranges.
Environmental conditions must not harm the thermistors. Use thermistors only in normal
atmospheric conditions.
Contact of NTC thermistors with any liquids and solvents should be prevented. It must be
ensured that no water enters the NTC thermistor (e.g. through plug terminals). For
measurement purposes (checking the specified resistance vs. temperature), the component
must not be immersed in water but in suitable liquids (e.g. Galden).
In case of exposure of the NTC thermistors to water, electrolytes or other aggressive media,
these media can penetrate the coating and reach the surface of the ceramic. Low-ohmic or
high-ohmic behavior may occur due to the formation of an electrolyte with metals (silver/lead/tin
from metallization or solder). Low-ohmic behavior is caused by electrochemical migration,
high-ohmic behavior by dissolving of the electrode. Ineither case, the functionality of the NTC
thermistorscannot be assured.
Be sure to provide an appropriate fail-safe function to prevent secondary product damage
caused by malfunction (e.g. use a metal oxide varistor for limitation of overvoltage condition).
Please read
Cautions and warnings
and
Important notes
at the end of this document.
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