Electrical Utility Cabinets and Ingress Protection Ratings (IP Code)- What You Need to Know
An electrical utility cabinet’s purpose is to house electrical or electronic equipment. This function is three-fold: 1) To mount switches, dials, and displays, 2) to prevent electrical shock to users, and 3) to protect the contents of the electrical utility cabinet from the environment. The electrical utility cabinet doesn’t just serve a practical function, but also is meant to be aesthetically pleasing or at least visually neutral.
What is an IP Code?
The International Electrotechnical Commission (IEC), the international standards and conformity assessment body for all fields of electrotechnology, publishes a classification system for the overall function of various classes of electrical utility cabinets. These standards include overall corrosion resistance from multiple sources such as rain, submersion, and intrusions of solid objects, dust and accidental contact. As a result, a cataloging system was constructed and consists of the letters “IP” followed by two digits or one digit and one letter and an optional letter. Finally, the digits indicate conformity with various conditions, when there is no protection with regards to one of the criteria; the digit is replaced with an “X.”
IP Code: First Digit
The first digit indicates the level of protection that the electrical utility cabinet provides against access to hazardous parts (i.e. electrical conductors, moving parts) and the possible entry of foreign solid objects. There are seven possible numbers for the first position (0-6).
IP Code: Second Digit
The second digit indicates the level of protection that the electrical utility cabinet provides against harmful entry of water. There are nine possible numbers for the second position (0-8).
Additional Letters:
The code defines additional letter that can be added to classify only the level of protection against hazardous parts by a person. There are four total letters (A, B, C, D). Four additional letters can also be used to provide additional information related to the protection of the device (H, M, S, W).
Additional Numbers:
An additional number has sometimes been used to specify the resistance of the electrical utility cabinet to mechanical impact. This mechanical impact is defined as the energy needed to qualify a specified resistance level, which is measured in joules (J). This has now been superseded by a separate IK number. Although dropped from later version of the code, older electrical utility cabinets will sometimes be seen with an optional third IP digit denoting impact resistance. Newer products, however, are more likely to be given a separate IK rating instead and to further complicate matters, there is not an exact equivalence of values between old and new standards.
Additional Information Regarding Ratings:
The United States National Electrical Manufacturers Association (NEMA) also publishes protection ratings for electrical utility cabinets enclosures similar to the IP rating system published by the IEC. However, it also dictates other product features not addressed by IP codes, such as corrosion resistance, gasket aging, and construction practices. Thus, while it is possible to map IP Codes to NEMA ratings that satisfy or exceed the IP Code criteria, it is not possible to map NEMA ratings to IP codes, as the IP Code does not mandate the additional requirements.
