IP protection classes of lighting fixture

  IP protection classes

IP-protection classes, as opposed to protection types, define the protective measures taken against the dangers voltage may cause when coming in physical contact with a human being or animal.

Protection class I

All conductive console parts of an operating device are connected to the earth wire of the permanent electrical installation. This is a protective earthing. 
In case of leakage current, a fuse will switch off the circuit. 

Protection class II

Operating materials in protection class II have a reinforced or double insulation between the grid circuit and conducting console.
This is known as a double insulation.  

Protection class III

Electrical devices in protection class III work with a maximum of 50 volts alternating current and in grid operation require a reinforced or double insulation between the grid circuit and outlet voltage. They require a safety transformer.