IP4X and IPXXD

[SgtTrojan]

My head is sconed and need the assistance of my learned forum members. I had it clear in my head but when I wanted to express it my way, I've got myself confused with all the different interpretations over the net (and I don't have the £150 for BS EN 60529

Once I've written this it will probably be all clearer anyway so here goes...

IP4X
GN3 states protection afforded is "Protection against the entry of wires.... greater than 1.0mm and solid objects exceeding 1.0mm in diameter" The test is made with a piece of wire 1mm + 0.05/0 mm (<<what ever that means). This tells me the test wire is not 1.0mm but actually a little larger, hence, not being able to enter a 1.0mm opening. So IP4X has to pass two tests, 1. Prevention of entry of the test wire and 2. Preventions of entry of objects greater than 1.0mm

This also tells me that 1.0mm wires can enter, which is contrary to pretty much all of the internet postings.

Now...

IPXXD
This time the top of the enclosure may allow the entry of the test wire but due to its stated length of 100mm it will not touch anything live within the enclosure. This means objects greater than 1.0mm will enter but will remain clear of live parts.


Give me a slap and tell me I am right please. If I am not slap me any and tell me why.

 

[stillp]

As the proud owner of a copy of BS EN 60529, I guess this falls to me!
For IP4X there is only one test needed, the requirement to prevent the entry of objects greater than 1.0 mm is considered to be verified by using the 1.0 mm probe (that can be very slightly larger, at 1.05 mm).
For IPXXD, the requirements of 60529 are that a probe of dia 1.0 mm, 100 mm long, shall have adequate clearance form live parts.
So, IP4X is actually a little more stringent than IPXXD.

I haven't a clue what GN3 says about these.

 

[SgtTrojan]

GN3 concurs with your explanation of IP4X but it doesn't give any guidance on IPXXD.

Protection against "Wires and strips of thickness greater than 1.0mm, and solid objects exceeding 1.0mm in diameter".

The test probe has to be greater than 1.0mm then otherwise 1.0mm will enter. What does it say about wire at right angles please?

 

[stillp]

Wire at right-angles to what?
The probe is a 100 mm length of 1 mm dia wire (not 1mm squared csa as one test lab thought!) protruding from a 35 mm dia sphere. if the probel penetrates it is then rotated in all directions and shall maintain "adequate clearance" to live parts. This is checked at 50 V for LV equipment. The 35mm dia stop face shall not fully penetrate.

 

[SgtTrojan]

GN3
"The test is made with a straight rigid steel wire of 1 mm + 0.05/0 mm diameter applied with a force of 1 N +/- 10%. The end of the wire must be free from burrs, and at a right angle to its length"

I know it's petty and probably not worth worrying about but it says straight and right angle in the same sentence.

 

[stillp]

I think that only means that the end of the wire is cut straight across, rather than at an angle like the end of a hypodermic needle. 60529 just says "edges free from burrs".

 

[SgtTrojan]

Ahhhhhhhhhhhhh, of course. Thanks chap. You've been a great help

 

[JohnW2]

The probe is a 100 mm length of 1 mm dia wire (not 1mm squared csa as one test lab thought!) protruding from a 35 mm dia sphere. if the probel penetrates it is then rotated in all directions and shall maintain "adequate clearance" to live parts. This is checked at 50 V for LV equipment.

What does "checked at 50 V" mean? Is it saying that the basic test is just done in terms of physical proximity of the probe to live parts, but that one then tests with voltage applied to them to see confirm that the probe does not come into contact with anything live?

Kind Regards, John

 

[stillp]

Broadly speaking yes John, although it's only a single test rather than 2 separate tests.
Hazardous live parts protected only by oxidation or paint/varnish are covered with metal foil during the test, and 50V applied between the foil and the proble or between the probe and other hazardous live parts. Before you ask (I know you're about to ) it doesn't specify AC or DC for the 50V.

 

[JohnW2]

Broadly speaking yes John, although it's only a single test rather than 2 separate tests.
Hazardous live parts protected only by oxidation or paint/varnish are covered with metal foil during the test, and 50V applied between the foil and the proble or between the probe and other hazardous live parts. Before you ask (I know you're about to ) it doesn't specify AC or DC for the 50V.

Ah, I see - thanks. When you wrote "this is checked at 50 V..." I interpreted 'checked' as meaning 'confirmed' - hence the reason I thought there were two tests (first measure proximity, secondly check with some volts!).

Kind Regards, John.