By Brent Bronner and Paul Hasenmeier
Published Friday, August 10, 2012
On a weekday evening, the radio comes to life, dispatching you to a general alarm fire at a hotel in your first-due district. Secondary calls report smoke in the hallway and smoke coming from one room on the exterior of the building. As the door of the station goes up, you notice a column of smoke on the horizon. In the back of your mind, you know you’ll need mutual aid for a working fire in this building.
As it turns out, the fire was caused by a heat sanitation machine, which seems to be a more frequent scenario in commercial occupancies and residential homes across America these days. Treatments can be performed on mattresses, wall coverings and even electric sockets within a confined room. Specifically, the primary way for sanitation to occur in commercial occupancies is by heating a room or rooms to around 150 degrees F for four hours. Typically, sanitation is achieved around 115 degrees F.
In this article, we’ll discuss what to look for during scene size-up when it comes to heat sanitation machines, how to secure the machines and their components, and machine hazards.
Important Size-Up Consideration
Back to our hotel example: You arrive on scene to find a hotel that’s evacuated and what appears to be a generator on a trailer nearby. A hotel manager informs you that they were sanitizing the room that’s on fire with heat treatment equipment.
During your initial size-up, determine whether a machine operator has secured the machine. If this hasn’t been done, seriously consider doing so. This might mean securing the machine before the first drop of water comes from the pipe.
Heat Sanitation Machine Set-Up
The machine operation is simple, but could be very dangerous to firefighters. A diesel-fueled generator, possibly on a tandem-axel trailer, supplies 480 volts through a main line (typically black) that will extend either vertically or horizontally into the structure to a junction box. The heavy-gauge main line connects to the junction box with a screw-type locking connector.
Fires have been known to start in the area of the junction box, as well as the back of the heater itself, due to tension being put on the plug portion from the weight of the cord. The cord can sometimes extend several stories up the side of the building and make a sharp bend when going over a balcony or through a window. This can cause aggressive bending in the cord, which can subsequently cause an electrical fire due to overheating and arcing. Note: Some hotels may have an internal chase that allows the main line cord to extend to higher floors without bending.
Once at the junction box, two cords carrying 240 volts will supply power to the two heaters (the normal number of heaters for this type of situation). Again, a temperature of 150 degrees F is needed for the four-hour bake. This process is performed in the affected room, as well as the surrounding rooms.
Fortunately, if you can’t locate the machine operator, shutdown operations are fairly simple once you identify that heat sanitation machine operations are underway. First, check the machine for operation by opening the main panel on the rear of the generator trailer. You may see three gauges on the panel that show readings in hertz, amps and volts. If the gauges are reading anything at all, secure the machine by turning the main breaker to the “off” position. This breaker should be located in close proximity to the gauges. Note: Some machines will have a manual stop button similar to the red emergency stop button commonly found at gas stations.
After the machine is secured in any variation, remember to use a lock-out/tag-out system; however, if the generator is equipped with an emergency stop button, it may be hard to secure with standard lock-out/tag-out kits. As an alternative, you may need to post a person by the generator to make sure the power isn’t turned back on.
Other ways power can be secured include turning off the power at the junction box. There’s an on/off switch on the top of the box, but remember, this only kills the 240-volt portion of the system; the 480-volt portion will still be live into the box.
The generator, junction box and heaters do have breakers and/or fuses in them for power surges and interruptions, but you shouldn’t always rely on these as the kill-all for the system. Take an extra minute to ensure the operator shuts down the system and/or secures it with fire department personnel—that’s always your safest bet.
If the generator trailer is on fire, treat it as if it’s energized and, if possible, shut off the generator motor. Remember: Exposures will be the key priority in this situation, since the generator trailer usually sits in close proximity to the building.
In the Fire Room
Fire from overheating or faulty equipment isn’t the only problem that’s being seen with this type of bed bug treatment. Other issues include sprinkler systems that have been disabled to prevent activation due to the heated environment.
The average sprinkler head in a hotel room will activate around 155 degrees F. There are two ways to keep this from happening: 1) cover the heads with an outdoor water faucet insulator, similar to what you’d see on a house in the winter time (this method has obvious faults once a fire starts) and 2) use a heat-sensing device pointed at the head, which regulates the heater to below sprinkler-activation temperatures.
If you arrive and determine water is flowing in the room being treated for bed bugs, be cautious of the energized equipment, and follow through with hitting the fire department connection and all fireground tasks. If you determine that the fire is out and the sanitation machine is de-energized, stop the flow of water from the sprinkler head after receiving approval from command. Your options may be to wedge the sprinkler, shut off the system at the riser or shut off the post indicator valve. Let your fire department guidelines dictate how and when you would shut down the sprinkler system.
Heat treatment is also performed in residential structures via the use of steam. The system includes a propane boiler, which will be found outside the structure, that pushes heated water to radiator-style heaters found inside the rooms being treated. The target interior temperature is around one 125 degrees F.
Important: All plastics and wall coverings should have been removed from the room to help prevent fire. All doors, windows and vents should also be found sealed up. If these tasks have not been completed, it could throw all the rules to reading smoke out the window.
Points to Remember
The goal of this article is to raise awareness to a hazard that firefighters are facing more often on a daily basis. Remembering a few key points could mean the difference between a great outcome and your worst day.
- When preplanning your district, pay attention to generators sitting in parking lots and investigate what kind of work is being done.
- When arriving on scene, dedicate someone to finding the operator or securing the machine.
- The big black cord leaving the generator carries a lot of power so treat it with care.
- Sprinkler heads may be covered in the fire room, so tactics may have to be bumped up in either line choice or the number of lines used to combat potential, unexpected, heavy fire situations.
- Breakers and fuses are not the kill-all for power. The only way to be totally sure all power remains shut down is to put your lock on the machine until the end of incident. This keeps the machine from being reset or re-energized.
- Do not fall into the trap of “It’s just another water flow alarm.”
- Check exposure rooms on all four sides of the effected rooms.
- Get an engine on the fire department connection.
- Electricity will kill you.
The process of heat sanitation in commercial and residential occupancies can be part of a preventive maintenance schedule, but it also exposes firefighters to many potential hazards. Use the information in this article to help prepare for the challenges you may face at a fire caused by a heat sanitation machine, and be sure to contact your local cleaning professionals and hotels to determine other variations used in your area. Lastly, be sure to pass on any information to other departments in your area that may also respond to similar structures.
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