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When planning for the installation of a 1.3-MW photovoltaic (PV) system and its integration into an existing facility's electrical system, an arc flash study was performed to determine the best protective device settings to minimize the arc flash energy in the PV system and to determine the effect of the additional short-circuit current on arc flash calculations for the existing system. The existing system has distribution at 13.8 kV and two 10-MVA transformers to a 2.4-kV feeder system. The PV system adds the hazard of 500-Vdc subarray collection wiring and terminations. The dc arc flash exposure of PV systems, including those in the inverter enclosures, can be complicated, and this paper outlines the basic data collected for the study, the steps taken to complete the calculations, the methodology used, the results, and the team's learnings. [ABSTRACT FROM AUTHOR]

In difficult economic times, companies sometimes delay the performance of maintenance on electrical power distribution equipment to save costs. If this happens, some circuit breakers (CBs) or protective relays will miss their scheduled maintenance and testing. This can create a significant safety risk if those protective devices are used to manage arc flash hazards. This paper describes a study method to determine which CBs and protective relays in a system are the most critical so that they can be prioritized for continued proper maintenance. [ABSTRACT FROM AUTHOR]

Electrical systems with AC voltage have been shown to exhibit arc flash incident energy during faults. Are there arc flash hazards related to dc systems, such as battery banks for UPS or drives, or dc buses used in chemical processes? Methods are available to estimate arc flash energy of ac exposures, but not dc. This paper will show the basic equations for maximum power from a dc arc and the resulting estimated arc flash incident energy. Research is required to find accurate values, but until research is completed, these equations can help the engineer provide a preliminary estimate of the thermal energy values for applying protective clothing for these exposures. [ABSTRACT FROM PUBLISHER]

The authors and their colleagues have used the methods in IEEE 1584 "Guide for Performing Arc Flash Hazard Calculations" to complete electrical hazard assessments for over 90 industrial sites, from small warehouse and office facilities to large chemical plants. This paper provides analysis of the results of those assessments, with an emphasis on the safety improvements that were made in design, work practices, and application of personal protective equipment. Modifying electrical equipment design, choosing good work practices, and applying sound engineering judgment can help to minimize arc flash hazard exposures and reduce costs due to injury and process downtime. [ABSTRACT FROM AUTHOR]

There have been recent advances in equipment de- sign and arc flash hazard assessment. It is possible to design a complete site electrical system, from transmission to distribution to utilization voltage, with the estimated arc flash energy below 20 cal/cm² (80 J/cm²) for all equipment. This paper describes a preferred design, where all workers can have proper arc flash personal protective equipment by using single-layer flame resistant everyday clothes and add a single-layer coverall for the higher energy tasks. Inherently safer design is in our future to reduce hazards and keep our workers safe. [ABSTRACT FROM AUTHOR]

The article reports on the arc flash of electrical hazards. Electrical hazards were regarded principally as electric shock or electrocution hazards. A person may not need to make a physical contact with an energized conductor to be a part of the electrical circuit and be injured by an arc flash. A victim can still be several feet away from energized conductors and still be severely injured by an intense thermal energy transfer from an electric arc. Arc hazards have been present in industrial and commercial facilities since the start of electrification. INSET: Arc Hazard Terms.

In 1960, a large global chemical company began documenting and implementing requirements for preventing injuries from electric arc flash hazards, including appropriate personal protective equipment (PPE). Methods evolved from requiring a 100% natural fiber long-sleeve shirt for a specific task to a detailed analysis with multiple flame-resistant clothing options. This paper compares the PPE required by these methods, based on hazards analysis in more than 65 manufacturing and laboratory facilities. The total costs for the example company are estimated for each method. [ABSTRACT FROM AUTHOR]

Provides a summary of the results of studies about arc-flash energy calculations. Learnings about electrical equipment design, installation and operation; Methods for evaluating the arc-flash energy values; Design issues found during studies.

Presents a study which described the improvements in modeling and evaluations of electrical power system reliability. Calculation of electrical reliability; Electrical power system evaluation.

A near-miss shock incident occurred on a heated air blower control panel during construction activities. This paper describes the investigation and findings of the team, with follow-up items to ensure that future equipment brought to the site will be properly inspected for safe design. [ABSTRACT FROM AUTHOR]