Hurricane season is officially upon us. Although the period can often begin earlier and run later, June 1 through November 30 is “hurricane season” as defined by the National Oceanic and Atmospheric Administration (NOAA). When an impending hurricane is expected to reach landfall, the days prior can be chaotic as those who may be affected scramble to protect their homes and businesses as much as possible. Belongings are secured, windows and doors are boarded up to combat strong winds, and sandbags are placed as barriers to the forthcoming inrush of massive amounts of water. Preparedness is clearly the focus in driving the best possible outcome at a challenging time.
After the storm has subsided, the recovery process begins. But planning for recovery can, and should, happen well in advance of the hurricane ever showing up on radar screens. An important area to consider for recovery is electrical systems.
Electrical power is a key component in reestablishing normalcy for many areas recovering from a severe storm. However, before electrical systems can be brought back online, it must be verified that restoring power can be done safely and does not pose any additional risks. A great resource for establishing a plan for analyzing and making any necessary repairs to electrical systems during disaster recovery is Annex K of NFPA 70B, Standard for Electrical Equipment Maintenance. Although Annex K is not part of the specific requirements of NFPA 70B, it is an invaluable resource for those recovering from a catastrophic event. It lists and elaborates on 11 sequential event phases that should be addressed prior to returning an electrical system to operation post-event. Those disaster event phases are broken down as:
1. Initial event
2. Securing the facility to limit damage
3. Mobilization of recovery personnel
4. Developing a safety plan
5. Temporary and emergency power generation
6. Initial damage assessment
9. Reenergization of the facility
10. System commissioning
11. Project summary
Recovery necessity can be driven by natural disasters or human-made disasters. Fire, for example, is an event that can happen from a lightning strike (natural) or from arson (human made). Natural events consist of floods, hurricanes, tornadoes, and earthquakes. Regardless of the cause of the event, there are commonalities in the types of damage that can occur to facilities. Structural damage is likely to occur during all events, although it may escalate during an earthquake. Water damage is common in floods, hurricanes, and tornadoes. But water damage also occurs regularly in fires where a significant amount of water is used to put the fire out. As is well understood, water and electricity do not mix, so special attention must be paid to electrical equipment that has been exposed to water before attempting to reenergize.
When the onset of an event like a hurricane is inevitable, the preparation leading up to it can influence how much recovery is needed. Securing the facility properly can help offset the amount of damage that is done. Boarding up windows and doors as well as placing sandbags to try and stop water are all helpful and commonly done in preparation. There are also electrical-specific preparation steps that should be considered, such as deenergizing equipment as well as elevating or removing critical equipment altogether.
Personnel to assist with recovery are a key part of the equation, and a plan to engage those who are needed to help must be put in place well in advance. Both in-house personnel and outsourced personnel should be considered as part of the recovery plan. Companies that offer their services for recovery can be contracted with ahead of time in order to ensure they are available when the need arises. It is also important to keep in mind, especially when it comes to electrical work, the need for qualified persons to perform specific work. The determination of the need for a qualified person is based on the specific task being performed. If a particular task requires a qualified person, that need must be met whether or not the laborer is supplied in house or by an outsourced contractor. So, it is important to verify that any company that is contracted with has qualified individuals on staff.
A site-specific safety plan should be in place before any potential disaster occurs. The plan should include typical electrical safety items such as lockout/tagout (LOTO), test before touch, application of safety grounds, and proper personal protective equipment (PPE). Because a disaster can introduce new safety concerns, there are also other safety considerations that need to be addressed and integrated into the safety plan, such as air quality, structural issues to the facility, and any potential chemical or biohazard spill. It is likely that there will be other unique, site-specific hazards that arise that personnel must be aware of, as well as any additional PPE needs that may arise due to those hazards. These additional safety concerns should be addressed as much as possible in the safety plan ahead of time, and necessary PPE should be purchased and on site prior to any potential disaster taking place.
With the loss of normal utility power regularly taking place during a disaster, temporary power is often utilized in order to reestablish critical systems and provide adequate lighting and power to work through the recovery process. Although the power may be temporary in nature, it still must be managed to reduce the risk of shock and arc flash hazards. There should be dedicated personnel in place responsible for temporary power, and all written standards and procedures for that work should be developed in advance. Back-feeding of equipment is something that should be thought out thoroughly and highlighted as part of the plan in order to manage worker exposure to electrical shock and arc flash hazards during the recovery process.
Initial damage after an event must be assessed by a site walk-through to determine equipment and system damage. All pertinent drawings and documentation should be made available to aid in this task. This will also require foresight to have the drawings and documents stored in a location on site where they will remain intact and accessible after the event or taken offsite for safe keeping and use after the event takes place. Creating electronic versions of these documents is also beneficial to ensure continued access as well as being able to share with multiple parties engaged in the restoration process. As a list of necessary repairs is created during the site walk-through, they should be prioritized into the following five categories and examples of equipment:
· Category 1: medium-voltage equipment including distribution transformers
· Category 2: low-voltage distribution equipment
· Category 3: electric motors
· Category 4: power and control wiring
· Category 5: balance of the plant electrical equipment
As part of the disaster recovery process, it may be necessary to remove electrical equipment or components for reinstallation at a later time, if not replacement altogether. In order to properly manage the process, each modification that takes place should be documented. Some of the steps that should be taken and detailed are tagging equipment, labeling wiring, taking pictures and/or sketching diagrams, and creating a master electrical equipment document.
The disaster recovery plan should be strategic about what equipment is brought back online first. The initial site walk-through, combined with the five prioritized categories listed above, should drive this strategy. Medium-voltage equipment typically serves as the backbone of the electrical power system for the facility and should be the primary focus of the initial recovery activities. Then, low-voltage equipment, motors, and power and control wiring should be attended to, in that order. Finally, any additional plant-specific electrical equipment that was not previously accounted for should be brought back into service.
Reenergizing an entire facility with utility power after a disaster has occurred should be cautiously planned and methodically implemented. It may be beneficial, where possible, to reestablish utility power a little at a time in smaller sections of the building to better manage the process while testing electrical equipment for proper performance. Ideally, utility power should only be restored after all affected equipment has been repaired or replaced to prevent unintended energization of equipment. As part of reenergizing, proper performance and operation of electrical equipment should be validated through a period of monitoring to verify and document that proper operation has been restored.
As a final step in the disaster recovery process, information should be gathered into a summary report that can be accessed for future reference. This information can be vital to reviewing the recovery as a whole to decide what was successful and what needs to be improved upon, in preparation for potential similar events in the future. Examples of useful information that should be documented are:
· As-found conditions of the electrical infrastructure
· Listing of equipment repaired or replaced
· Test results of all equipment tested before and after service or repairs
· Assessment of individual equipment condition
· Long-term equipment replacement plan
Without question, Mother Nature has a mind of her own that cannot be controlled, and she can unleash her fury at any given moment. However, what can be controlled is preparedness for when that moment arises and having a thorough and strategic plan in place for a safe recovery from disasters, such as hurricanes. American polymath Benjamin Franklin once famously quipped, “By failing to prepare, you are preparing to fail.” As we embark upon the 2023 hurricane season, the path to a successful recovery is to ensure we are prepared.
NFPA® has several resources to help with recovery from natural disasters, including this Natural Disaster Electrical Equipment Checklist, which utilizes NFPA 70B to help determine whether equipment should be repaired or replaced, as well as additional information on emergency preparedness.