Connector Oxidation
The oxide layer forming on connector pins and terminal surfaces raising the contact resistance. The result is charging that does not start or starts intermittently, heating at the terminal, and operating faults that look random but are caused by low voltage.
When a clean metal surface meets air it forms a thin oxide film. This film behaves close to an insulator; if the contact pressure is sufficient the film is punctured and contact is made, but when the pressure weakens or there is moisture/salt, the resistance rises rapidly. Increased resistance produces more heat at the same current, the heat accelerates oxidation, and the process feeds itself.
- Symptom: charging starting when the charger is nudged slightly while plugged in, discolouration or a burnt smell around the terminal, voltage measuring lower than expected under load.
- Maintenance: keep the pins dry and clean; do not plug in the charging connector with dusty hands. Retighten the terminal screws periodically.
- Measurement: measure the voltage drop between the two ends of the connection you suspect, under load; even a drop of a few hundred millivolts indicates a problematic contact.
The AXI-Link 3-pin industrial charging connector on the ST100 and ST200 remote controls, and the receiver terminals, are the first points to check for this in the field.
The context in which this term is used: Wireless Crane Remote Control Selection Guide