When you are installing electrical enclosure outdoors, you will need to consider two different types of resistance: water resistance and impact resistance. Water resistance will prevent water from entering the enclosure, but impact resistance will prevent the enclosure from breaking if a physical force hit the enclosure. Furthermore, an electrical enclosure may be waterproof but may break if an individual hits the electrical enclosure with a tool or there foot.
To understand how much impact resistance an electrical enclosure has, you will need to use the IK rating system to measure how much energy the enclosure can absorb before it cracks or lose its seal. You will also use this system to purchase the correct electrical enclosure for installations such as driveways, car parks, or public walkways. The IK system rate how much force the electrical enclosure can take.
Choose the Right Outdoor Electrical Box for Water and Impact Protection
The lowest ratings indicate that the electrical enclosure can only take light pressure, but the highest ratings allow the electrical enclosure to take a hit from a sledgehammer. Most electrical enclosures does not need the highest impact resistance ratings. If the electrical enclosure has an impact resistance rating that is too low for the installation site, however, you will have to purchase and replace the enclosure frequent, leading to potential safety issues.
It is important to understand the difference between the IP ratings of an electrical enclosure and the IK ratings. The IP ratings indicate how much water can enter the electrical enclosure, but it does not factor in how much impact the electrical enclosure can take. Consider two enclosure that have the same IP protection but different IK ratings.
In this scenario, the electrical enclosures will have different protections for the housing of the electrical enclosure. Therefore, it is important to look at both of these ratings to ensure that an electrical enclosure has the appropriate protection and to avoid purchasing an electrical enclosure that people may assume is impact-resistant but which is not. Different laboratories around the world perform the testing to ensure that electrical enclosures are able to stand up to impact using calibrated hammer that are dropped onto the electrical enclosure from specific heights.
These tests ensure that the test is repeatable and consistent. Furthermore, these tests apply five blows to the weakest part of the electrical enclosure with the goal of ensuring that the electrical enclosure maintains its original IP protection after these five impacts. The tests also factor the temperature of the electrical enclosure into the tests to account for brittleness of materials such as plastic when they are exposed to cold temperature.
Residential lights and fixtures that is installed in porches and gardens require a middle-range impact resistance for electrical enclosures. Debris from lawnmowers or the boot of an individual walking on a patio hit these fixtures, but are not hit by any deliberate attacks on the enclosures. Commercial locations require higher impact rating than residential areas.
Locations where shopping trolleys and cars may hit the enclosures require these higher impact resistance electrical enclosures. Industrial locations will require even higher impact resistance electrical enclosures because the tools that may fall into these enclosures or the vibrations from the movement of industrial equipment may impact the electrical enclosure. Public infrastructure and secure facilities have some of the highest impact resistance requirement.
Locations like transit platforms and prisons have the potential for individuals to intentionally hit the electrical enclosures in an attempt to disable the electrical device that are located at these locations. In these locations, the electrical enclosure is not just a shield against the weather, but part of the security of the location. Therefore, locations transition from private to public infrastructure create an immediate increase in the required impact resistance of electrical enclosures.
The material used to create an electrical enclosure impacts its ability to take impact resistance. Polycarbonate material work well for electrical enclosures that need a midrange impact protection rating but are relatively inexpensive. The downside to polycarbonate is that it scratches easy.
Additionally, the material may craze if exposed to certain chemicals. Die-cast aluminum materials have a similar strength to the weight of the electrical enclosure and can take durable finish. Stainless steel electrical enclosures have the highest impact ratings but are more expensive and heavy relative to other materials.
Finally, glass reinforced plastic materials fall somewhere in the middle of electrical enclosures because they are chemically resistant like polycarbonate but do not weigh as much as stainless steel enclosures. For most installation site, purchasing electrical enclosures with the maximum impact resistance will increase the purchase price of the electrical enclosure and complicate the installation process of mounting the electrical enclosure. An electrical enclosure should have an impact resistance that reflect the risk of the installation site.
For instance, electrical enclosures installed at four meters in height within a warehouse do not have to have the same impact protection as electrical enclosures mounted to the height of an individual’s head within a public corridor. A chart exists that depicts each application of electrical equipment and the necessary impact resistance rating of the electrical enclosure. Furthermore, impact resistance relate to maintenance of the electrical enclosure.
Even if electrical enclosures can stand a fall from a hammer blow, they may need anti-tamper feature to prevent people from opening them. High-risk area require individuals to consider the mounting method for the electrical enclosure as importantly as the impact resistance of the electrical enclosure itself. Using a recessed installation or protective cage around high-risk electrical enclosures may provide the same level of impact protection as purchasing electrical enclosures with high impact protection ratings but at a lower cost.
To determine the appropriate electrical enclosure for each installation site, individuals should consider the IP and IK ratings of the electrical enclosure. By matching the IP and IK ratings to the environment in which the electrical enclosures will be installed, individuals can ensure that the equipment will last for longer period of time, experience fewer failures in its seals, and require fewer repairs to maintain their function.