IPX4 – Splashing of Water

“Water splashing against the enclosure from any direction shall have no harmful effect, utilizing either: a) an oscillating fixture, or b) A spray nozzle with no shield. Test a) is conducted for 10 minutes. Test b) is conducted (without shield) for 5 minutes minimum.”

IPX5 – Water Jets

Wikipediia: “Water projected by a nozzle (6.3 mm) against enclosure from any direction shall have no harmful effects.”

IPX6 – Powerful Water Jets

Wikipediia: “Water projected in powerful jets (12.5 mm nozzle) against the enclosure from any direction shall have no harmful effects.
IPX6K (Powerful Water Jets): Water projected in powerful jets (6.3 mm nozzle) against the enclosure from any direction, under elevated pressure, shall have no harmful effects. Found in DIN 40050, and not IEC 60529.”

IPX7 – Immersion Up To 1 Meter

Wikipediia: “Ingress of water in harmful quantity shall not be possible when the enclosure is immersed in water under defined conditions of pressure and time (up to 1 m of submersion).”

IPX8 – Immersion of 1 Meter or More

Wikipediia: “The equipment is suitable for continuous immersion in water under conditions which shall be specified by the manufacturer. However, with certain types of equipment, it can mean that water can enter but only in such a manner that it produces no harmful effects. The test depth and/or duration is expected to be greater than the requirements for IPx7, and other environmental effects may be added, such as temperature cycling before immersion.”