AUST – HENDRY building surveyors observe that it is surprising to note that the Building Code of Australia does not specifically reference the Standard AS/NZS 3000: 2007 ‘Electrical Installations’ (known as the Australian/New Zealand Wiring Rules). However, many Australian Standards referenced by the Building Code of Australia in specification A1.3 do reference the the wiring rules.  AS/NZS 3000:2007 ‘Electrical Installations’ requires live parts of electrical systems to be inside a protective enclosure that is protected to a minimum IP standard. Clause of AS/NZS 3000 specified this level of protection to be provided as follows:

  • IPXXB or IP2X, and
  • IP4X for horizontal surfaces that are readily accessible

The IP4X requirement can also apply to an enclosure provided by a floor and other components of a building that when moved, could displace or expose the electrical installation.

This means that barriers and enclosures must be firmly secured in place with adequate stability and strength to withstand any appreciable dislodgement or exposure of the electrical installation. The degree of protections is expressed as an IP (international protection) rating in accordance with AS 60529-2004 ‘Degrees of protection provided by enclosures (IP Code)’. AS 60529 details how an IP rating is established for an electrical enclosure required to protect a person against hazardous electrical parts, protection of the equipment against solid foreign objects and against the ingress of water.

The Code also designates the degree of protection and the test to be performed to verify an enclosure meets the requirements. Appendix G of AS/NZS 3000 provides a guide to the IP rating system.

The rating system of the standard is as follows:

First Numeric 

0     Not protected.
1     Protected against solid objects 50mm in diameter or greater. A large surface of the body, such as a hand (no protection against deliberate access).
2     Protected against solid objects 12mm in diameter or greater. Fingers or similar objects not exceeding 80mm in length.
3     Protected against solid objects 2.5mm in diameter or greater. Tools, wires, etc., of diameter or thickness greater than 2.5mm.
4     Protected against solid objects 1mm in diameter or greater. Wires or other similar solid material of thickness greater than 1mm in diameter.
5     Dust protected. Dust does not enter in sufficient quantity to interfere with satisfactory operation of equipment.
6      Dust tight. No ingress of dust.

Second Numeral 

Designates protection of the equipment inside the enclosure against harmful ingress of water.

0       Not protected.
1       Protected against dripping water. Dripping water (vertically falling drops) shall have no harmful effect.
2       Protected against dripping water when tilted up to 15°. Vertically dripping water shall have no harmful effect when the enclosure is tilted at an angle up to 15° from its normal position.
3       Protected against spraying water. Water falling as a spray at any angle up to 60° from the vertical shall have no harmful effect.
4       Protected against splashing water. Water splashing against the enclosure from any direction shall have no harmful effect.
5       Protected against water jets. Water projected by a nozzle against enclosure from any direction shall have no harmful effects.
6       Protected against heavy seas. Water from heavy seas or projected in powerful water jets shall not enter the enclosure in harmful quantities.
7       Protected against the effects of temporary immersion. Ingress of water in harmful quantity shall not be possible when the enclosure is immersed in water under defined conditions of pressure and time.
8        Protected against continuous immersion. The equipment is suitable for continuous immersion in water under conditions which shall be specified by the manufacturer.

Additional Letter

A      Used with first number Resists penetration of 50mm and sphere to live parts.
B      Used with first numbers 0 & 1 Test finger penetration to a max of 80mm must not contact live parts.
C      Used with first numbers 1 & 2 Wire of 2.5mm diameter X100 long must not contact live parts.
D      Used with first numbers 2 & 3 Wire 110mm diameter X100 long must not contact live parts.

Supplementary Letter

H      High voltage unit.
M      Tested for harmful effects of water ingress when moveable parts are in motion.
S       Tested for harmful effects of water ingress of a moveable part when stationary.
W      Suitable for use under specified weather conditions when provided with additional protective features.


IP  4 3 A  W
First Number
0-6 or X
Second Number
0-8 or X 
Letter A,B,C, D
Letter H,M,S,W

Result of examples
4:         Protection against solid objects on wire 1mm in diameter or greater.
3:         Protection against sprayed water.
A:         Resists penetration of 50mm in diameter of sphere.
W:        Suitable for use under specified weather conditions.

Builders and electricians must always be vigilant to ensure electrical rules are not compromised when protection is provided to electrical installations by parts or components of a building.

Building Legislation Table

Refer to our Building Legislation table for further information on the building approval process including alternative solutions.

Fire Safety Compliance: Essential Safety Measures

Refer to our Essential Safety Measures Identification Table for further information on individual essential safety measures and the Annual Statement.

Further Advice

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