Keeping Water and Foreign Objects Out of Electrical Enclosures

With so many different ratings for ingress protection — from NEMA ratings, to UL standards, to the European IEC ingress protection (IP) ratings appearing more frequently in the U.S.— keeping the standards straight can be challenging. When you consider that each rating is designed to specify the protection required to safeguard your electrical system and protect your workers, you can see that it’s crucial to have a minimum basic understanding of what the different ratings mean. Here is an overview of the IEC IP ratings, NEMA ratings, and UL standards.  IEC IP Ratings IP ratings are specified by the International Electrotechnical Commission (IEC) 60529 standard. They consist of the letters “IP” followed by two numerals, of which the first specifies protection against solid bodies and the second specifies protection against water. NEMA Ratings and the Correlation to IP Ratings While the above IEC IP ratings only cover liquid and solid body ingress protection, National Electrical Manufacturers Association (NEMA) ratings for enclosures, specified in the NEMA 250 standard and corresponding UL Standards 50 and 50E, cover ingress protection and more, including the enclosure design and corrosion protection. For the purposes of specifying ingress protection only, the following are general translations between NEMA ratings and IEC IP ratings: Note: Testing procedures and pass/fail criteria for NEMA and IEC ratings are different. Therefore, these are rough equivalents provided for reference only. What happens when you make a connection? Most enclosures that come off a manufacturer’s production floor and are stocked in a distributor’s warehouse are UL® listed, meaning you can be sure they meet a certain UL50/UL50E standard to meet the requirements of your application for ingress protection and more. But as all of us in the industry know, once electrical enclosures are installed and loaded with the equipment they’re meant to protect, they must then be connected to an electrical system to function. Liquid-tight flexible metallic conduit and liquid-tight fittings can be applied in these circumstances. The standards for liquid-tight conduit and fittings are UL360 and UL514B respectively. In theory, connecting UL360 liquid-tight flexible metallic conduit with UL514B liquid-tight fittings to a UL50E enclosure should maintain ingress protection. In reality, one simply doesn’t know without conducting further testing of the complete assembly. Learn more about NEMA ratings for enclosures with the free visual guide below. The opinions expressed in this piece are solely Thomas & Betts'. They do not necessarily represent WESCO’s views. 

Food-Grade Products: What Electrical Professionals Need to Know

Strategic marketing or labeling that uses the term “food grade” has caused a great deal of confusion in the food and beverage industry. It’s led companies to believe they are buying a food-safe product when, in truth, they may not be. The assumption is that the food-grade product has been subjected to rigorous testing to ensure safety throughout the food and beverage processing environment. But, in fact, there is no industry certification called “food grade.” Who decides and regulates what’s food-safe? A common mistake is thinking that either the U.S. Department of Agriculture (USDA) or the Food and Drug Administration (FDA) tests products and gives those that pass a rating of “food grade.” This is not so. The FDA is responsible for assuring the safety and security of our nation’s food supply, among other things. The USDA inspects food to ensure the safety of the American public. The role of assuring that components and equipment used to process food are safe falls to the National Sanitation Foundation International (NSF). Products that carry the NSF symbol have been certified for safe use in specified areas of food and beverage facilities. What is the NSF? Founded in 1944 with a mission to protect and improve global human health, the NSF is an independent, accredited organization that tests, audits, and certifies products and systems, as well as provides education and risk management services. NSF International has been helping businesses in the agriculture, processing, food equipment, restaurant, and retail industries to navigate the food safety and regulatory environment for more than 70 years. The organization’s extensive suite of food safety and quality services spans every link in the food chain, from farm to fork, including certification, testing, training, consulting, auditing, and regulatory compliance. What is the NSF’s goal? Simply put, the goal of the NSF is to ensure that food does not become contaminated by materials or equipment that come into direct contact with food or are used in areas near food products during processing or packaging. These include materials such as plastics, lubricants, and sealants, as well as machinery, systems, and components. NSF is focused not on the food itself, but on the machinery used in the food-making or packaging process. Four NSF Zones The NSF has established a set of rigorous tests to ensure that the products being examined are worthy of the NSF mark. The organization follows the American National Standards Institute (ANSI) standards development process to define a product for application for NSF accreditation. This testing is confined to four specific zones to determine food grade: Zone 1 — Food Zone: This zone includes areas where direct contact with food products is normally expected and surfaces from which the food may drip, drain or splash back into surfaces normally in contact with food. Zone 2 — Splash Zone: This zone includes areas where direct contact with food products during normal operations would not be expected. However, equipment in this area may be situated in such a way that during processing or cleaning (or both), liquids may splash, spill or otherwise soil the surfaces. Once splashed, there is a chance that liquids might drip down onto surfaces that contact foods. Zone 3 — Non-Food Zone: This zone includes areas where no contact with food is expected. These areas are not subject to typical wash-down procedures. In the area, care must be taken to prevent physical deterioration of materials that could lead to migration into food contact areas. Zone 4 — The Unexposed Non-Food Zone: This zone includes areas that are within the same facility but separated from the food and splash zones by walls or other physical barriers. NSF Policies All NSF certification programs are governed by certification policies that are referenced in the contract. The policies provide an overview of the rights and responsibilities of both the certifier and the manufacturer. They offer clear rules on the use of the NSF mark on products, labels, and advertising, and prohibit misrepresentations. They also provide information on product recalls by the NSF and public notice when a certified product is thought to present a public health concern. Due process is afforded in the event of appeals to administrative hearings. What’s involved in attaining NSF certification? To obtain the NSF listing, the facility where the product is made must be thoroughly audited by an NSF representative. This ensures that the product is constructed in a sanitary manner and that the standards for sanitary design elements are actually met during construction and assembly. The equipment is reviewed and tested before approval (Zone 4 products are not tested). The NSF has developed more than 50 voluntary American National Standards under the scope of health and safety for food service equipment. Inspectors look closely at these standards before granting the NSF listing. Below is a brief and general overview of some of the things the NSF considers when granting a listing: Physical design and construction evaluation for ease of cleaning Materials (look for corrosion or heat resistance, durability and nontoxicity) Performance Sanitation effectiveness Accuracy of control systems UL Certification Millions of products, from consumer electronics to commercial cooking equipment, carry the UL (Underwriters Laboratories) symbol. UL certification means the product and its components meet a set of safety and hazard standards that ensure the safety of the product’s users. Over the last 100 years, UL has become the primary authority on product safety. The UL label on equipment means it has met a set of standards that UL recognizes as ensuring that the equipment operates in a safe manner. This includes electrical, design and structural elements of restaurant equipment. UL conducts ongoing analyses of products to make sure that they continue to meet safety standards. UL also has a sanitation certification for equipment that is important to food safety — an important source of confidence for the food and beverage industry. Overcoming Facility Challenges Food and beverage processing facilities constantly face issues that are critical to keep their processes up and running. These include liquid ingress, corrosion and harsh environments, safety and contamination, extreme temperature, hazardous locations, continuous operation, and safety. Factor these issues in when designing a product for the food zone. Understanding NSF and UL certificiations will ensure that your equipment is ready to provide safe and clean food and beverages.  The opinions expressed in this piece are solely Thomas & Betts'. They do not necessarily represent WESCO’s views.