Maintaining Electrical Protective Devices

Several studies have shown that electrical protective devices, which were not maintained within a five-year period, have a 50% failure rate. Maintenance of the circuit breakers generally consists of keeping them clean and lubricated.

Dennis Neitzel, CPE

June 23, 2003

2 min read

Several studies have shown that electrical protective devices (circuit breakers and relays), which were not maintained within a five-year period, have a 50% failure rate. Maintenance of the circuit breakers will generally consist of keeping them clean and properly lubricated. The frequency of maintenance will depend on the manufacturer’s recommendations and the cleanliness of the surrounding area. If dust, lint, moisture, or other foreign matter is present, then more frequent maintenance is necessary.

If these devices are not properly maintained, an excessive time delay in operations could occur which would affect the outcome of the Flash Hazard Analysis required by NFPA 70E-2000, Part II, paragraph 2-1.3.3. The Flash Hazard Analysis must be performed before anyone approaches exposed electrical conductors or circuit parts that have not been placed in an electrically safe work condition. In addition, Paragraph 2-1.3.3.2 requires a flash protection boundary to be established. All calculations for determining the incident energy of an electrical arc and for establishing a flash protection boundary require the arc clearing time. This clearing time is derived from the engineering coordination study, which is based on what the protective devices are supposed to do.

Maintenance is a very critical part of the flash hazard issue. Evidence has proven that inadequate maintenance can cause unintentional time delays in the clearing of these devices during a short circuit condition. If, for example, a low-voltage power circuit breaker had not been operated or maintained for several years and the lubrication had become sticky or hardened, the circuit breaker could take several additional cycles, seconds, minutes, or longer to clear a fault condition.

Neitzel is the director of the AVO Training Institute, Dallas, Texas

About the Author

Dennis Neitzel, CPE

Director Emeritus

Dennis K. Neitzel, CPE, Director Emeritus of AVO Training Institute, Inc., Dallas, has more than 47 years of experience in the electrical industry in various capacities, specializing in electrical equipment and systems maintenance, testing, engineering, inspection, and safety. He is a past chair of the IEEE-IAS Electrical Safety Workshop (2012). He is an IEEE Senior Member, and is also a member of ASSE, AFE, IAEI, SNAME, and NFPA. Neitzel is a certified plant engineer (CPE) and a certified electrical inspector-general. He is a principle committee member for the NFPA 70E, Standard for Electrical Safety in the Workplace since 1992; working group chair for IEEE Std. 3007.1-2010 Recommended Practice for the Operation and Management of Industrial and Commercial Power Systems, IEEE Std. 3007.2-2010 Recommended Practice for the Maintenance of Industrial and Commercial Power Systems, and IEEE Std. 3007.3-2012 Recommended Practice for Electrical Safety in Industrial and Commercial Power Systems, IEEE Std. 45.5-2014 Recommended Practice for Electrical Installations on Shipboard-Safety Considerations; co-author of the Electrical Safety Handbook, McGraw-Hill Publishers; and co-author of Chapter 20–Electrical Safety – Construction Safety Management & Engineering, 2^nd Edition, published by ASSE. Neitzel earned his bachelor’s degree in electrical engineering management and his master’s degree in electrical engineering applied sciences.