POWR-GARD White Papers

POWR-GARD White Papers On Circuit Protection

Short Circuit Current Ratings: How to Determine and Increase Short Circuit Current Ratings for Industrial Control Panels

SCCR labeling requirements create a safe installation and help manufacturers, owners and managers meet OSHA regulations and NFPA codes and standards. Both the NEC and OSHA forbid equipment from being located near any point where the available short-circuit current is more than what the equipment can withstand. Available fault currents are increasing in industrial facilities due to a continuously increasing demand for electric power. When available fault currents at the equipment exceed the panel’s SCCR, there can be catastrophic results. Current-limiting fuses can optimize a panel to give it a strong competitive advantage over molded case circuit breakers (MCCB) so long as SCCR is considered in its design. Most MCCBs do not provide adequate SCCRs. The most traditional way to increase a panel’s low SCCR that is caused from an MCCB is to replace the MCCB with current-limiting fuses. But after making this improvement to the panel, how can you increase the panel’s SCCR even further?


Motor Protection: The Importance of Effective Motor and Motor Circuit Protection

The importance of effective motor and motor circuit protection cannot be over emphasized. Motors are consistently the largest single cause of industrial and commercial fires, and in today’s highly automated commercial and industrial facilities, the failure of even one relatively minor motor may shut down an entire installation. As a result, it is vitally important that there is at least a basic understanding of how motors and their related electrical systems can be properly protected. The purpose of this White Paper is to provide a more detailed discussion of the factors which must be considered when properly selecting and applying low voltage fuses, medium voltage fuses, and protection relays in electrical systems.

Transformer Protection: The Importance of Effective Transformer and Control Transformer Protection

The importance of effective transformer and control transformer protection cannot be over emphasized. After motors, transformers are typically the second most common application where proper overcurrent protection is required and utilized to provide the necessary protection to facilities, electrical systems, equipment, and most importantly electrical workers and other involved personnel. As a result, it is vitally important that there is at least a basic understanding of how transformers and their related electrical systems can be properly protected. The purpose of this white paper is to provide a more detailed discussion of the factors which must be considered when properly selecting and applying low voltage fuses and medium voltage fuses in electrical systems.

Ground-Fault Protection for Solar Applications

Grid-connected commercial photovoltaic (PV) systems are trending towards larger sizes, resulting in systems with higher bus voltage and current levels. Problems caused by ground faults are becoming a bigger concern due to increased energy available at the point of fault; arc-flash and shock hazards, equipment damage, and fires can result.

Medium Voltage Fuses: Selecting and Applying Medium Voltage Fuses • 2,400 - 38,000 Vac

Medium voltage fuses are applied quite differently than fuses rated 600 volts and less. The biggest difference is that medium voltage fuses are not intended to provide overload protection. They should only be applied in situations where it will not be required to open small overcurrents. Medium voltage fuses offer a much wider range of system voltages, thereby resulting in a correspondingly large number of fuse voltage ratings. This white paper contains details of factors which must be considered when properly selecting and applying medium voltage fuses in electrical systems.

Arc-Flash Assessments: Misconceptions About Arc-Flash Hazard Assessments

There are some common misconceptions about Arc-Flash Hazard Assessments which reduce the effectiveness of the Assessments and can increase electrical hazards. These misconceptions exist because of the confusion about the laws and standards that apply regarding Arc-Flash Hazard Assessments. It is important to note that the Occupational Safety and Health Administration (OSHA) may rely on numerous consensus standards to enforce their regulations, and this may vary by state. Further confusion is caused by the various methods used to calculate and quantify Arc-Flash hazards. When deciding to do an Arc-Flash assessment, it is vital to determine what is being offered by a service company and what is required by OSHA or local authority having jurisdiction (AHJ). The goal of this paper is to discuss some of the common misconceptions regarding Arc-Flash Hazard Assessments and clarify what OSHA and the National Fire Protection Association® (NFPA®), actually require.

Flood Damage: Recommendations for Re-Energizing Flood-Damaged Electrical Equipment

Littelfuse reminds electricians and managers of industrial facilities and large commercial buildings of the hazards associated with working around electrical equipment that has been exposed to flood water, and provides instructions for a safe restoration. Flood waters are generally contaminated, and leave conductive and/or corrosive residues inside equipment that can produce shock and fire hazards. Affected equipment should be replaced or refurbished to avoid risk of fire and shock.