Visual 2803-69

The current rating of a contact is defined as the current level that creates a certain temperature rise of the contact spring — usually 20°C or 30°C. Both electrical and thermal factors govern the heat created by the current.

IP (or "Ingress Protection") ratings are defined in international standard EN 6529 (British BS EN 6529:1992, European IEC 659:1989). They are?used to define levels of sealing effectiveness of electrical enclosures against intrusion from foreign bodies?(tools, dirt etc) and moisture.