IEC 529
Protection Grades
IEC (
International Electrotechnical Commission )
The IEC has established an enclosure grading system that produces an IP
rating. (For example, IP 54 - "5" is the first character - refer to
tables I & II. "4" is the second character - refer to table III -
following page).
Table I - Degrees of Protection against Hazardous Parts
(Degree of protection is indicated by the first characteristic numeral)
Number |
Brief Description |
Definition |
0 |
Non Protected |
xxx |
1 |
Protected against access to hazardous
parts with the back of a hand. |
The access probe, sphere of 50 mm ø, shall have adequate
clearance from hazardous parts. |
2 |
Protected against access to hazardous
parts with a finger. |
The jointed test finger of 12mm ø, 80 mm length, shall have
adequate clearance from hazardous parts. |
3 |
Protected against access to hazardous
parts with a tool. |
The access probe of 2.5 mm ø shall not penetrate. |
4 |
Protected against access to hazardous
parts with a wire. |
The access probe of 1.0 mm ø shall not penetrate. |
5 |
Protected against access to hazardous
parts with a wire. |
The access probe of 1.0 mm ø shall not penetrate. |
6 |
Protected against access to hazardous
parts with a wire. |
The access probe of 1.0 mm ø shall not penetrate. |
Note: In the case of the first characteristic numerals 3, 4, 5
and 6, protection against access to hazardous parts is satisfied
if adequate clearance is kept. Due to the simultaneous
requirement specified in Table II the definition "shall not
penetrate" is given in Table I. |
Table II - Degree of Protection against Solid Foreign Objects
(Degree of protection is indicated by the first characteristic numeral)
Number |
Brief Description |
Definition |
0 |
Non Protected |
xxx |
1 |
Protected against solid foreign objects of
50 mm ø and greater. |
The object probe, sphere of 50 mm ø, shall not fully penetrate.¹ |
2 |
Protected against solid foreign objects of
12.5 mm ø and greater. |
The object probe, sphere of 12.5 mm ø, shall not fully
penetrate.¹ |
3 |
Protected against solid foreign objects of
2.5 mm ø and greater. |
The object probe of 2.5 mm ø shall not penetrate at all.¹ |
4 |
Protected against solid foreign objects of
1.0 mm ø and greater. |
The object probe of 1.0 mm ø shall not penetrate at all.¹ |
5 |
Dust-protected |
Ingress of dust is not totally prevented, but dust shall not
penetrate in a quantity to interfere with satisfactory operation
of the apparatus or to impair safety. |
6 |
Dust-tight |
No ingress of dust |
Table III - Degrees of Protection against Water
(Degree of protection is indicated by the second characteristic numeral)
Number |
Brief Description |
Definition |
0 |
Non Protected |
xxx |
1 |
Protected against vertically falling water drops |
Vertically falling drops shall have no harmful effects. |
2 |
Protected against vertically falling water drops when enclosure
tilted up to 15°. |
Vertically falling drops shall have no harmful effects when the
enclosure is tilted at any angle up to 15° on either side of the
vertical. |
3 |
Protected against spraying water |
Water sprayed at any angle up to 60° on either side of the
vertical shall have no harmful effects. |
4 |
Protected against splashing water |
Water splashed against the enclosure from any direction shall
have no harmful effects. |
5 |
Protected against water jets |
Water projected in jets against the enclosure from any direction
shall have no harmful effects. |
6 |
Protected against powerful water jets |
Water projected in powerful jets against the enclosure from any
direction shall have no harmful effects. |
7 |
Protected against the effects of temporary immersion in water. |
Ingress of water in quantities causing harmful effects shall not
be possible when the enclosure is temporarily immersed in water
under standardized conditions of pressure and time. |
8 |
Protected against the effects of continuous immersion in water. |
Ingress of water in quantities causing harmful effects shall not
be possible when the enclosure is continuously immersed in water
under conditions which shall be agreed between manufacturer and
user but which are more severe than for numeral 7. |
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