How important is electrical equipment maintenance to the safety conversation? Well, on one hand, you have maintenance for equipment longevity and, on the other, is maintenance for the safety of those performing work with electrical equipment. The latter can be found in Chapter 2 of NFPA 70E: Standard for Electrical Safety in the Workplace and is well established. Requirements for maintaining PPE, test equipment, temporary grounding equipment, GFCIs and OCPDs can be found in NFPA 70E, and all have a direct impact on safety. However, what role does electrical equipment preventive maintenance have on safety? We need to know.
NFPA 70E emphasizes properly maintaining equipment, and the committee for NFPA 70B: Recommended Practice for Electrical Equipment Maintenance determined it was time to make NFPA 70B into a standard. For longer than I've been around, NFPA 70B has always been a recommended practice and was chock full of great recommendations related to maintenance. NFPA 70B encourages owners of electrical systems to build an electrical equipment preventive maintenance program based on manufacturer recommendations. But there was always something that seemed to be missing from this approach. For more on this standard, read “A New NFPA Standard in 2023” from the December 2022 issue of ELECTRICAL CONTRACTOR.
Redefined Chapter 9
One of the most interesting additions/revisions—and my choice of the change for safety and maintenance with the most impact—is in the newly redefined Chapter 9. We are getting a table that tells us when we need to perform certain tasks for various types of electrical equipment. This is an evolution of the table that previously existed in Annex L, but it goes a step further to consider the condition of the equipment being maintained.
This is the work horse of the new Standard for Electrical Equipment Maintenance. Based on what physical condition the equipment is in, the standard will give guidance on what maintenance tasks need doing and how often to do them.
So, what do we mean by the “condition” of the equipment? Chapter 9 in NFPA 70B also has this covered. It spells out that there are different types of conditions for us to consider during the equipment condition assessment, including the physical, criticality and operating environment conditions. The assessment required by NFPA 70B will then assign a number to equipment based on each of these different types of equipment conditions. Whichever number is the highest will be used in applying Table 9.2.2 intervals.
Let’s look at an example. A 5-kilovolt switchgear is installed in a generating facility. First, let’s look at this equipment installed in an enclosed electrical room and then at this same equipment installed near the water cooling fans. The equipment is brand-new, so the physical condition assessment is simple, condition 1. It is in the best physical condition it can be, like new.
What about the criticality condition? If this equipment were to fail, would there be an immediate safety concern? Severity of an arc flash has a lot to do with how quickly the upstream overcurrent protection device functions to open the circuit under arcing fault conditions. If the circuit breakers in this switchgear do not perform as advertised, it is reasonable to assume that failure will endanger personnel. So, from a criticality condition standpoint, this looks like a strong case for condition 3.
Finally, we assess the operating environment condition. When this equipment is installed in an enclosed electrical room, it is safe to assume that it is rated for the nice, protected environment and is likely going to be condition 1. However, if we installed this in the vicinity of the cooling fans, it would be subject to overspray water that contains corrosive elements. In this case, the equipment owner might assess the operating environment condition as a 3. Either way, the condition assessment points us to condition 3 due to the equipment’s critical nature. Table 9.2.2 then tells us that condition 3 requires us to perform items such as visual inspections and mechanical servicing at tighter intervals than conditions 1 or 2.
Maintenance is the final cog in that electrical safety ecosystem, and NFPA 70B is preparing for its moment in the spotlight. Having this standard to guide the industry on maintenance will be a giant leap forward. Look for the new edition of NFPA 70B in LiNK shortly. The three-legged stool of electrical safety is evolving, and we all get to reap the benefits. When we have proper installation, work practices, and now, proper maintenance, we are that much closer to providing the workplace as free from electrical hazards as possible. That is what it is all about.
Header image courtesy of Forest Electric Corp.