IP specifications 1

[solocam92]

I am looking to test fractional hp electric motors for IP66 and 67. Is it necessary to test for both dust and water? My thoughts are that if there is no water ingress there shouldn't be any dust ingress and vice versa. Therefore I was just going to test the IPX6 and X7 water specification and assume that the motor would also pass the IP6X specification for dust.

 

[BrianPetersen]

How much is hanging on the result of the test?

Is it foreseeable that the lawyer for the prosecution will have you up on the witness stand, asking the question "Did you perform test X" after some sort of failure has resulted in a multi-million-unit recall, or worse?

 

[zdas04]

The flow mechanism for water is very different from dust. With water you have to account for surface tension and cohesion that can significantly reduce the rate of incursion for small leaks. Dust flow tends to be discrete instead of continuous so you don't have to be very concerned about surface tension or cohesion. Passing the water test does not provide confidence that you'll pass the dust test. And vice versa.

David Simpson, PE
MuleShoe Engineering

In questions of science, the authority of a thousand is not worth the humble reasoning of a single individual. —Galileo Galilei, Italian Physicist

 

[MintJulep]

If your assumption were true there wouldn't be two digits in the rating.

 

[solocam92]

Thanks for the help guys