Honeywell Switches and Sensors - Manual (Page 9)

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LIMIT SWITCHES
A Note on Degrees of Protection
IP Classification
The IEC 529 standard describes a system for classifying the degree of
protection provided by the enclosures of electrical equipment. The level of
protection given by the enclosure is indicated by the IP code. This code
system uses the letters ‘‘IP’’ (International Protection) followed by up to four
digits. Normally only the first two digits are used.
IP 1st Digit 2nd Digit 3rd Digit 4th Digit
The first digit is numerical and indicates the level of protection within the
enclosure against the ingress of solid foreign objects and access to hazardous
parts by persons.
The second digit is also numerical and indicates the level of protection
against the ingress of WATER into the enclosure.
The third digit is a letter and indicates a higher level of protection for persons
against access to hazardous parts.
The fourth digit is also a letter and is used in exceptional cases for
supplementary information.
If the first or second digit is not required to be specified, then it is replaced by
the letter ‘‘X’’ (‘‘XX’’ if both digits are not required). While the tables below
serve as a guide to the level of protection, Honeywell recommends that
customers refer to the full official IEC specification for the exact definitions. If
in doubt about the degree of protection required for a particular application,
please consult your local Honeywell office.
Note:
The IEC 529 standard does not relate to protection against rust, corrosion,
icing or corrosive solvents (e.g. cutting fluids) and that product coded IP 67
may not necessarily meet IP 66 requirements.
First Digit Protection against ingress of solid objects
IP TEST
0 no protection
1 protected against solid objects with a diameter greater than 50 mm
2 protected against solid objects with a diameter greater than 12 mm
3 protected against solid objects with a diameter greater than 2.5 mm
4 protected against solid objects with a diameter greater than 1 mm
5 protected against dust-limited ingress (no harmful deposit)
6 totally protected against dust
Second Digit Protection against ingress of water
IP TEST
0 no protection
1 protected against vertically falling drops of water
2 protected against vertically falling drops of water when the enclosure is tilted
at an angle up to 15 degrees
3 protected against water sprayed at an angle of 60 degrees from the vertical
4 protected against splashing water from all directions – limited ingress (no
harmful effects)
5 protected against low pressure jets of water from all directions – limited
ingress permitted
6 protected against powerful jets of water from all directions – limited ingress
permitted
7 protected against the effects of temporary immersion in water
8 protected against the effects of continuous immersion in water
NEMA Classification (USA)
NEMA (National Electrical Manufacturer’s Association) prepares standards
which define a product, process or procedure with reference to one or more of
the following: nomenclature, composition, construction, dimensions,
tolerances, safety, operating characteristics, performance, quality, electrical
rating, testing and the service for which designed. This standard provides
degrees of protection for Enclosures for Electrical Equipment (1000 Volts
Maximum) similar to that of the IEC 529 standard. The reference standard
herein reflects the latest data in the NEMA Standards Publication when this
information went to print. Please check for the latest information.
Non-hazardous locations
Type 1 enclosures are intended for indoor use primarily to provide a degree of
protection against contact with the enclosed equipment.
Type 3 enclosures are intended for outdoor use primarily to provide a degree
of protection against windblown dust, rain, sleet, and external ice formation.
Type 4 enclosures are intended for indoor or outdoor use primarily to provide
a degree of protection against windblown dust and rain, splashing water, and
hose-directed water.
Type 4X enclosures are intended for indoor or outdoor use primarily to
provide a degree of protection against corrosion, windblown dust and rain,
splashing water, and hose-directed water.
Type 6 enclosures are intended for indoor or outdoor use primarily to provide
a degree of protection against the entry of water during occasional temporary
submersion at a limited depth.
Type 6P enclosures are intended for indoor or outdoor use primarily to
provide a degree of protection against the entry of water during prolonged
submersion at a limited depth.
Type 12 enclosures are intended for indoor use primarily to provide a degree
of protection against dust, falling dirt, and dripping noncorrosive liquids.
Type 13 enclosures are intended for indoor use primarily to provide a degree
of protection against dust, spraying water, oil and noncorrosive coolant.
Note:
Enclosures are based, in general, on the broad definitions outlined in NEMA
Standards. Therefore, it will be necessary to ascertain that a particular
enclosure will be adequate when exposed to the specific conditions that might
exist in intended applications.
Except as might otherwise be noted, all references to products relative to
NEMA enclosure type are based on Honeywell evaluation and Underwriter’s
Laboratory (UL) tested. This NEMA Standards Publication does test for
environmental conditions such as corrosion, rust, icing, oil, and coolants. The
IEC 529 does not, and does not specify degree of protection against
mechanical damage of equipment. For this reason, and because the tests and
evaluations for other characteristics are not identical, the IEC Enclosure
Classification Designations cannot be exactly equated with NEMA Enclosure
Type Numbers.