After A Storm: Schneider Electric Urges Caution During Electrical-System Recovery Efforts

Recent storms that brought torrential rain, mudslides, winds and power outages to areas of the West Coast should serve as a strong reminder to all industrial operations. Given the fact that water and electricity don’t mix, restoring power to water-damaged equipment can be a dangerous undertaking.

Chad Kennedy, the Industry Standards Manager for Power Equipment at Schneider Electric, says that while businesses everywhere face increasing pressure to maximize profits and minimize downtime, they should take every precaution during power-restoration activities to  ensure the safety of all concerned. His company offers sound advice for plant personnel that might find themselves dealing with weather-related damage to their operations.

According to the Federal Emergency Management Agency (FEMA), 40% of businesses don’t reopen after a disaster. The response and actions taken during the first 24 to 48 hours of a catastrophic event are crucial in determining whether or not a business will fully recover.

After a natural disaster, it’s crucial to quickly and efficiently assess the damage. The following precautions are recommended to ensure employee safety and avoid costly damage both to physical equipment and the financial losses of a prolonged shutdown:

Wet electrical equipment

• Electrical equipment that has been submerged or come into contact with water must be replaced, though there are exceptions to this rule for larger equipment, which may be able to be reconditioned by trained factory service personnel. Equipment that may be reconditioned includes:
  • Switchboard enclosures and certain bus structures;
  • Switchgear;
  • Low-voltage power circuit breakers;
  • Medium-voltage circuit breakers;
  • Low-voltage bolted-pressure switches;
  • Medium-voltage switches;
  • Motor control center enclosures and bus structure;
  • Panelboard and load center enclosures;
  • Liquid-filled power transformers’
  • Cast-resin transformers; and,
  • Busway: epoxy coated bars.
• Attempting to dry out the equipment (in many cases) leaves portions of the current-carrying parts with damp or wet surfaces. These surfaces may be in contact with insulators or other materials that prevent them from being properly dried out and cleaned of debris.
• Residual debris or wet surfaces may result in a loss of dielectric spacing within the equipment, and could present a hazard upon re-energization.
• Equipment that must be replaced in its entirety includes:
  • Miniature and molded case circuit breakers;
  • Molded case switches;
  • Multi-metering equipment;
  • Safety switches (AC and DC);
  • Load centers or panelboard interiors;
  • Dry-type transformers;
  • Busway: mylar wrapped bars;
  • Solid state components;
  • Programmable logic controllers;
  • Fuses;
  • Electromechanical relays, contactors, starters, push buttons, limit switches
    and other input logic and output controls;
  • Solid state motor starters;
  • Adjustable speed drives;
  • Motor-control-center components.

Equipment with field replaceable interior components
Generally, this type of replacement is limited to a load center or panelboard type of product where the entire assembly can be removed and replaced as a unit. In this case, there is a possibility that enclosures can be reused if they have not been subjected to physical damage and if they have been properly cleaned of all debris and foreign materials.

Regarding cleaning agents and abrasives
Do not apply cleaning agents, particularly petroleum-based cleaners, to the current-carrying portions of electrical equipment to remove foreign debris, residues and other substances. Some cleaning and lubricating compounds can cause deterioration of the non-metallic insulating or structural portions of the equipment. Do not use abrasives such as sandpaper or steel wool to clean current-carrying parts of the equipment. These materials may remove plating or other conductive surfaces from the parts, which could result in a hazard when the equipment is re-energized.

Non-submerged equipment in flooded areas
Equipment in this situation should be inspected carefully by a qualified person to determine whether moisture has entered the enclosure. If any signs of moisture or damage exist, the equipment should be replaced or repaired.

Relevant codes and standards
Businesses should reference relevant industry codes and standards to ensure they are taking the safest possible route to recovery. NFPA 1600 is the overarching standard and primary document on disaster recovery, emergency management, and business continuity. For workplace safety and planning, OSHA references NFPA 70E, Standard for Electrical Safety in the Workplace. NFPA 70B, Recommended Practice for Electrical Equipment Maintenance now includes a chapter on electrical disaster recovery in the 2013 edition. In addition, the National Electrical Manufacturer’s Association (NEMA) has published “Evaluating Water-Damaged Electrical Equipment” and “Evaluating Fire- and Heat-Damaged Electrical Equipment.”

References

• FEMA, Protecting Your Businesses, 2013 (http://www.fema.gov/protecting-your-businesses)
•  NEMA Standard AB 4-2003, Guidelines for Inspection and Preventive Maintenance of Molded Case Circuit Breakers Used in Commercial and Industrial Applications
• NEMA Standard BU 1.1-2000, General Instructions for Proper Handling, Installation, Operation, and Maintenance of Busway Rated 600 Volts or Less
• NEMA Standard PB 1.1-2002, General Instructions for Proper Installation, Operation, and Maintenance of Panelboards Rated 600 Volts or Less
• NEMA Standard PB 2.1-2002, General Instructions for Proper Handling, Installation, Operation, and Maintenance of Deadfront Distribution Switchboards Rated 600 Volts or Less
• NEMA Standard ICS 1.1-2003, Industrial Control and Systems: Safety Guidelines for the Application, Installation, and Maintenance of Solid State Controls

About Schneider Electric
Schneider Electric, manufacturer of Square D equipment, works with property owners to address questions about water-damaged equipment and offers inspection, testing and reconditioning and/or replacement services. The Schneider Electric Services group can address questions about water-damaged equipment and offers a variety of services, including inspecting, testing and reconditioning of electrical equipment from any manufacturer.