404/406XR Series Product Manual
Appendix A - Internal Protection
38
Parker Hannifin Corporation
1140 Sandy Hill Road
Irwin, PA 15642
www.parkermotion.com
Appendix A - Internal Protection
The 404XR is protected from its environment via magnetically retained Protective Seals. Parker Hannifin
Corporation has conducted testing to determine the
degree
to which the positioner is protected by using
a British standard called an
Ingress Protection Rating (IP Rating)
.
Definition
Reference: British standard EN 60529 : 1992
This standard describes a system of classifying degrees of protection provided by enclosures of
electrical equipment. Standardized test methods and the establishment of a two digit numeric rating
verify the extent of protection provided against access to hazardous parts, against ingress of solid
foreign objects, and against the ingress of water.
First Number
– The first number indicates protection of persons against access to dangerous parts and
protection of internal equipment against the ingress of solid foreign objects.
1
- Protection against access to hazardous parts with the back of a hand, and protected against
solid foreign objects of 50 mm diameter and larger.
2
- Protection of fingers against access to dangerous parts, and protection of equipment against
solid foreign objects of 12.5 mm diameter and larger.
3
- Protection against access to hazardous parts with a tool, and protection against solid foreign
objects of 2.5 mm diameter and larger.
Second Number
– The second number indicates protection of internal equipment against harmful
ingress of water.
0
- No special protection provided.
Note: Number Indicators above represent only a partial list of IP Rating specifications.
Warnings (Points of Clarity)
The specification applies to protection of particles, tools, parts of the body, etc., against access to hazardous
parts inside the enclosure. This does not cover external features such as switch pinch points, pinch points
caused by the motion of the carriage, or cable carrier assemblies.
The testing method as specified in the standard uses a solid steel rod of the appropriate diameter at a
specified force. The specification does not consider soft or pliable particles. Due to the design of the table and
sealing method, a soft particle can compress due to the motion of the table, and reduce its cross-section. This
can allow particles to enter the unit.
In application, shavings or chips commonly created in a machining operation are a greater concern. If any
edge or dimension of the “chip” is under the appropriate diameter, it can wedge under and start to the lift the
seals. This action will allow larger particles to do the same until failure is reached.
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