PLC DC inputs are generally 12 to 24 VDC at a few milliamps. The rated current for general-purpose Basic Switches is 5 to 10 A. Contacts use silver. Sulfide gas and oxidizing gas in the atmosphere form an insulating film on the silver contact surfaces, which results in contact failures. Use Microload Basic Switches that use gold alloy contacts.

Example: Z Basic Switch

Standard model: Z-15GW22-B, Microload model: Z-01HW22-B