404LXR Series Product Manual
Appendix B
– Internal Protection
46
Appendix B - Internal Protection
The 404LXR is protected from its environment via a magnetically retained protective
seal. Parker 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 causes 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.
