Borrowed But Good

 I 

Mile Stones

    Though this topic is not my normal fair, I wanted to take time and share a personal mile stone. This adventure stated 40 years ago, and I have been wanting to closed the door on this task for a long time. I have completed my BS Degree I started on when I was 18 years old. A girl, beer and life got in the way, but I was determined to fulfill this life goal, and I have now completed that task.

    You should never give up on your goals. It may take much longer for you to achieve them than you originally thought It may. Goal setting is important for your development as a leader. You set goals and objectives and get people to join on the journey…. That is what leading is about. 

   Always remember what you do is more important than what you say, lead by example, and do the right thing, even if no one is there to the you do it.

JB

Firefighter Safety and Utility Control: The Unseen Dangers of Alternative Power Sources

 

            Typical fireground operations are centered on creating safety and eliminating threats. The fire 

departments have time tested tools like Layman’s RECEO VS to give the incident commander a 

reference point. Departments drill to save lives, with hose line deployment and fire attack skills as well 

as search and rescue methods to save potential victims. Additional duties include securing a water 

supply, meeting the two-in and two-out standard, ventilating, and salvage and overhaul operations. 

Often overlooked or an afterthought is securing the utilities.

               In California the typical home and business is serviced by natural gas and electricity. In the more rural areas propane is typically used for heating, cooking, and cleaning. In some areas heating oil is used in the furnace. With consumer solar systems, battery and generator back-up power systems being used more often, what was once a simple turn of a valve and flip of a breaker to secure the utilities has now become complicated.

               My volunteer company responded to a gas leak at a local seed research facility. We arrived at the scene and were met by the staff who reported that a gas valve in a laboratory had been damaged and had been releasing gas for well over an hour before it was discovered. The crew ensured that all the staff was accounted for, and conducted a hazard assessment, determined if there was anyone needing medical attention and secured both the natural gas and power, eliminating potential fuel and ignition sources. At first glance they believed that the major hazards had been controlled, but it was not until later in the incident that the company officer realized the computer workstations were still powered. They all had an uninterruptible power supply or UPS system.
               The building was charged with natural gas, but because the department did not have monitoring equipment the firefighters did not know if the gas concentration was above, below or within the flammable range. The container was full of flammable gas and whether the UPS could provide an ignition source is unknown, but we were not as safe as we first thought. As the crew completed their operations, now aware of the missed power supplies, they noticed additional battery powered equipment including the emergency egress lighting and the exit lights. As the incident commander it is critical to consider the devices as potential ignition sources. Given the right conditions they could provide the means to create an explosion and/or fire.
               Though exit and emergency lights and UPS units are common items in commercial occupancies, many people use the UPS for their home computers also. There are two common systems in use today: standby UPS and continuous UPS. A standby UPS runs the computer on the normal utility power until it detects a problem. At that point, it very quickly (in five milliseconds or less) turns on the power inverter and runs the computer off the UPS's battery. A power inverter simply turns the DC power delivered by the battery into 120-volt, 60-Hertz AC power.
               In a continuous UPS, the computer is always running off of battery power and the battery is continuously being recharged. The battery charger continuously produces DC power, which the inverter continuously turns back into 120-volt AC power. If the power fails, the battery provides power to the inverter. There is no switch-over time in a continuous UPS. This setup provides a very stable source of power.
               Standby UPS systems are far more common for home or small-business use because they tend to cost about half as much as a continuous system. Continuous systems provide extremely clean, stable power, so they tend to be used in server rooms and mission critical applications. The hazard to firefighters from the UPS can come from electric shock, heat generation and the chemical reaction from the charging process. Other locations where you will find UPS and battery back-up systems are at cell phone sites and electric utility sub-stations.

               These systems typically use a wet cell lead-acid battery. When these batteries charge, they produce hydrogen gas, which is the same gas that created the Hindenburg disaster. If this gas is not properly ventilated it will accumulate and find an ignition source. In March 2001, the Sacramento Metropolitan Fire District responded to a report of a building explosion in Rancho Cordova, CA. Upon further investigation they found a computer company’s battery back-up system had exploded. They found several walls blown over and visible smoke from a room that housed several large batteries. Firefighters also reported that a 40-foot section of the roof was missing just over the area of the explosion.
               The energy released by an explosion can injure and even kill responders. Other concerns for firefighters can include back-up generator systems. These systems are designed to supply power to the building in the event of a power system failure. These systems must have a system to switch between the power sources- the utility company or the generator. This switch is typically automatic and will activate when there is any interruption in the utility power supply like when we turn off the power. This can prove to be a problem when firefighters are attempting to eliminate the electrical hazards at an emergency scene. 

               Preplanning and onsite training with the building maintenance personnel will give fire companies an opportunity to understand how the system works and how to overcome the automatic operation. Even more dangerous to the firefighters is the illegal generator hookups, without the required switch; the power can come from either source. It is common for the do-it-yourselfer to create what is morbidly referred to as a suicide plug, an extension cord with two male ends, one that plugs into the generator and the other into a receptacle in the home. Also associated with the illegal hook up is the improper use of the gasoline powered generator. The generator is a common cause of CO poisoning, and was the origin of a recent house fire, caused from the heat from the generator’s engine operation and exhaust. The potential for a generator illegally installed, remote from where a company is operating, may back feed an entire block of homes leading to an unseen electrocution hazard. Many utility companies may use capacitor banks that store engery to keep a power system energized. Despite the assurance that the power is secured, it may be preferable that the crews ensure the power is off before performing over-haul operations. One option is a personal electrical power sensor. (See Fig 1) that allows for non-contact method to determine if a power line is energized.

               The use of Lithium-Ion battery systems is an emerging threat with many documented fatal fires from personal mobility devices; e-bikes and scooters that have exploded and burned after thermal run-a-way of the batteries. The number of electric vehicles on the road, powered by Li-on batteries is growing and are exposing the public and firefighters to uncontrolled fire hazards from a run-away battery condition. My agency responded to a collision involving a Tesla sedan. The resulting fire required four hours and 10,000 gallons of water to stop the battery run-away and resulting fire.  

               The use of Li-on battery systems to power homes is also a growing trend. The Tesla Powerwall was the original purpose-built home battery back-up energy storage system (ESS). The homeowner who could not afford a Tesla system created home-made battery system that may lack the safety and engineering standards of a commercial product. The Tesla system produces 350 to 450 volts of direct current (DC) and 9.4 amps, enough to kill a person, direct current or not. Tesla in no longer the sole provider of energy storage systems. The market has many other options including better chemistry other than the Li-On. A new battery chemistry is the Lithium Iron Phosphate (Li Fe Po), which has a longer life span that can be recharged 10-fold more than the Li-On battery. To date Li Fe Po batteries have not created a battery run-away condition and the associated fires and other dangerous conditions. DC power requires an inverter to transition the power to the common 120 volts of alternating current (AC) to power the home or business. The inverter may be integrated into the home’s power system, or it may be used to convert the stored energy from an ESS to power the residence. The power company may use a “smart meter” that prevents the solar panels from directly powering a home when the grid is down. This system also prevents the back-feeding into the grid which may endanger power company and fire personnel working where the power system is apparently deenergized.

               Most battery systems are charged via photovoltaic solar panels. The panels are typically placed on the roof of a new home, especially in California where the building code requires the installation of the panels. The issue with solar panels is that there is no “off” switch. When the panels are receiving sunlight, power is being produced. The panel may produce dangerous voltages and damaged wires on the roof top may expose firefighters to the hazards of the power generated by the panels. To stop the power production the panel will need to be shielded from the sun. A heavy opaque salvage cover may be the best method to cover the panels and prevent the production of power.

               Another power generation option is the use of a hydrogen fuel cell to create a micro-grid to support operations of businesses to reduce the companies carbon footprint. A noted business using this technology is Home Depot, where the company plans on using the fuel cell system to power a warehouse in Texas and other systems supported the operation of several locations in New York state during a blackout.

               The off-grid lifestyle may also pose an issue with securing power supplies to those homes. Many people living off grid are accomplished do-it-your-selfers, who create their own power sources that lack the safety features of a commercial application. It may be a small hydroelectric generator, wind turbine, solar panels or a combination of all three that powers the home and creates independence from the power companies.

               So, the next time that you are assigned to secure the utilities, realize that you may have not completely de-energized the building. The use of UPS, battery backups or generator systems may continue to provide power and ignition sources in the building. There are many alternative means to power homes and businesses and what was once a simple task has become complicated and may require additional training to safely secure the power and ensure that the firefighters can operate with out fear of being injured by an electric shock or an arc that may create an unexpected ignition source.