The Spray Nozzle Alternative for IPX3 and IPX4

For large or awkward enclosures, the oscillating tube cannot be positioned correctly. IEC 60529 therefore allows a spray nozzle as an alternative for IPX3 and IPX4, with a specified baffle and flow.

The nozzle

The spray head has a counterweighted baffle that breaks the jet into a spray, with a specified orifice and a delivery of about 10 litres per minute at 50 to 150 kPa. The distance is 300 to 500 mm from the enclosure, and the spray is moved over the surface at about 15 degrees per second.

Differences from the tube

The spray is less uniform and more dependent on operator technique. The standard requires the whole surface to be covered, and the duration is 1 minute per square metre with a minimum of 5 minutes. Two laboratories using different operators can produce different results, which is why the tube is preferred where it fits.

Documenting it

The test report must state which method was used, the nozzle type, the flow and the distance. A report that simply says IPX4 without the method is not reproducible, and a buyer comparing two suppliers may be comparing two different tests.

Related technical notes

• IP54 or IP65: Reading Both Digits Together
• What an IP Test Report Must Contain
• IPX7 and IP68: What the Marking Legally Means