Contact adhesion or wear causes safety function failure
Problem: The forced guide contact is adhered (cannot be disconnected) or worn for a long time (poor contact) due to excessive arc, causing the safety circuit to fail.
Cause: The contact capacity does not match the load (such as insufficient inductive load margin); the load is frequently switched on and off; the contact is oxidized/dusted.
Solution:
Select by load: For inductive load, select a model with arc extinguishing function or capacity ≥ 3-5 times the peak current, and for resistive load, select a model with 1.2 times the rated current;
Install a surge suppressor to reduce arc damage;
Check regularly (every quarter), replace when the contact resistance is > 0.1Ω, and clean the contacts.
