Posted in: Safety Corner, March/April 2018
Maintenance is a part of each of our lives in one manner or another, important for both longevity and safety. We invest in vehicle maintenance not only to ensure it lasts but also to be sure key components, like brakes, work when we need them. The electrical distribution system is a system that should receive the same level of attention that many things do in our lives, but unfortunately it doesn’t receive the attention important to ensure performance over the life of the facility it serves. We can’t take a set-it and forget-it mentality and expect these systems to last forever. This realization is the beginning of your journey to a long-lasting, well performing system that will pay dividends.
MINDSET OR CULTURE
I once received a call pertaining to our IQ 1000 II motor protection relay, and the caller on the other end of the phone asked for my assistance in disabling ground fault protection. At some point in the call, he revealed that the reason he wanted to turn ground fault off was because he wanted to burn up the cables and the motor so he can replace them. You see, he had a budget to replace this equipment but did not have a budget to maintain it. For quite some time I thought about that call and would get a good laugh.
It took me some years to realize how sad of a call that really was. There is no humor in a situation that puts individuals in a position to work around a system possibly putting lives at risk. This story happens all too often and establishes the baseline of our journey to change the safety culture in our industry.
MAINTENANCE AND THE NEC
The Purpose of the NEC is the practical safeguarding of persons and property from the hazards due to use of electricity. Section 90.1(B) speaks to the fact that the NEC contains provisions that are necessary for safety; “Compliance therewith and proper maintenance results in an installation that is essentially free from hazard but not necessarily efficient, convenient, or adequate for good service or future expansion of electrical use.” Electrical equipment will perform as expected when installed correctly and maintained over its life.
The NEC has provisions to help those who are performing maintenance on electrical equipment. The following sections are examples of this:
- 110.26, Spaces About Electrical Equipment
- 110.32, Work Space About Equipment
- 110.34, Work Space and Guarding
- 110.76, Access to Vaults and Tunnels
The 2017 version of the NEC expanded maintenance requirements for emergency systems as part of 700.3, "Tests and Measurements." Article 700 focuses on requirements around emergency systems required to operate when normal power goes out. It's about life safety. Maintenance is very much a part of the picture. The new 700.3(C) added the following language:
"Emergency system equipment shall be maintained in accordance with manufacturer instructions and industry standards."
Maintenance increases the level of confidence that a system, like that which is dedicated to life safety, functions as it was deisgned and intended to function in times of emergency.
MAINTENANCE AND NFPA 70E
NFPA 70E, "Standard for Electrical Safety in the Workplace," has an entire chapter - Chapter 2 - focused on safety-related maintenance requirements. This document reminds us that when we use the phrase "properly maintained," we mean equipment has been maintained in accordance with the manufacturer's recommendations and applicable industry codes and standards. NFPA 70B, "Recommended Practice for Electrical Equipment Maintenance," is a well-referenced document to help provide guidance with this regard.
Maintenance is important for safety for many obvious reasons and some not so obvious. When calculations are made on a power distributions system for incident energy for example, some very basic assumptions are made. First, we assume that the various components and equipment within the distribution system have or are being applied properly within their rating. We also assume that the overcurrent protective devices will have expected clearing times based upon their time-current characteristic (TCC) curve. But what happens when the circuit breaker that has been on for the past 20 years has never been maintained per the manufacturer instructions? How about all of those motors that have been added over the life of the system that are now contributing fault current? We can’t forget the changes at the utility that increased the available fault current values throughout the system. The electrical infrastructure at one time had equipment with the right interrupting ratings and SCCR ratings, but someone has to review changes to make sure that situation persists over the life of the system.
YOUR MAINTENANCE JOURNEY
Maintenance is critical for safety on many levels. Safe and long-lasting power distribution systems must be looked at
through three important documents. It’s important to understand and employ the following pillars of success:
1. Leverage the following the three key references as your foundation:
a. NFPA 70, The National Electrical Code, includes installation requirements and provides the bare minimum requirements for safety.
b. NFPA 70E, The Standard for Electrical Safety in the Workplace, provides necessary information required for electrical worker safety.
c. NFPA 70B, Recommended Practice for Electrical Equipment Maintenance, provides maintenance information to help reduce hazards to life and property that can result from failure or malfunction of industrial-type electrical systems and equipment.
2. Plan ahead
a. Plan for maintenance by installing solutions that provide workers an ability to reduce safety risk while performing necessary maintenance on the electrical distribution system.
a. Have a maintenance budget at the ready. Companies spend thousands for generators, motors, switches, receptacles, and the like, but without maintenance that money is essentially wasted.
These are just suggestions for discussion with your team. Embrace maintenance and make it a part of your business planning.
As always, keep safety at the top of your list and ensure you and those around you live to see another day.
Thomas Domitrovich, P.E. is VP of Technical Sales for Eaton’s Bussmann business within the Circuit Protection Division of Eaton Corporation. Thomas is based out of St. Louis MO and has more than 25 years of experience as an Electrical Engineer. He is a LEED Accredited Professional and a licensed Professional Engineer in the state of Pennsylvania. Thomas is active in various trade organizations including the Independent Electrical Contractors (IEC), International Association of Electrical Inspectors (IAEI), Institute of Electrical and Electronic Engineers (IEEE), National Electrical Manufacturer’s Association (NEMA) and the National Fire Protection Association (NFPA). Thomas is Principle member on Code Making Panel 2 for the National Electrical Code (NFPA 70) and an Alternate member on NFPA 73 for electrical inspections of existing dwelling units both representing NEMA.