How to handle USB charging cable overheating or melting issue

This is an article on corrective action and preventive action (CAPA) for the problem of USB charging cable overheating / melting problem observed in some old generation 1 units.

Some of the earliest systems (Gen 1) shipped by SIERA.AI had generation 1 (Tripp-Lite U325-001-KPA-BK) USB charging cables. In some cases, they have been observed to overheat or melt. This may cause the charging port of the tablet to get blocked due to accumulation of molten insulation of the cable, thus requiring the tablet to be replaced.

SIERA.AI Engineering team has come up with the following solution:

  • Gen 2 USB charging cable (Tripp-Lite UO38-006-GY-MAX) needs to be used in place of the old cable.
  • In case there is no inrush filter (current limiter) installed, then it needs to be installed  for the overall improvement in the electrical protection. Please check FMN 1 for S2 and FMN 2 for S3.
  • In case you are experiencing the same situation in any of your units, please send an email to SIERA.AI Technical Support at with the number and type (S2 or S3) of Siera devices you have and the approximate dates (if available) on which they were installed. Our tech support will send the needed USB cables, inrush filters and associated documentation to you.
  • In case you need one of our Field Engineers to visit your site for this, then the engineer's visit charges will apply.