B57237S100M Datasheet, PDF (18/20 Pages) EPCOS – NTC thermistors for inrush current limiting

Inrush current limiters
ICLs
B57237S0***M0**
S237
Mounting
When NTC inrush current limiters 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 NTC inrush current limiters.
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 NTC inrush current limiters only within the specified operating temperature range.
Use NTC inrush current limiters only within the specified voltage and current ranges.
Environmental conditions must not harm the NTC inrush current limiters. Use NTC inrush
current limiters only in normal atmospheric conditions.
Contact of NTC inrush current limiters with any liquids and solvents should be prevented. It
must be ensured that no water enters the NTC inrush current limiters (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 inrush current limiters 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. In either case, the functionality of
the NTC inrush current limiters can not 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).
This listing does not claim to be complete, but merely reflects the experience of EPCOS AG.
Display of ordering codes for EPCOS products
The ordering code for one and the same EPCOS product can be represented differently in data
sheets, data books, other publications, on the EPCOS website, or in order-related documents
such as shipping notes, order confirmations and product labels. The varying representations of
the ordering codes are due to different processes employed and do not affect the
specifications of the respective products. Detailed information can be found on the Internet
under www.epcos.com/orderingcodes
Please read Cautions and warnings and
Important notes at the end of this document.
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