Hurricane Effects
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Hurricanes have certain effects on equipment your emergency plans may have not considered.   The following information is for Emergency Communicators so that you can learn from our experiences.

 

Generators in a Hurricane:

The low air pressure of a hurricane can cause many generators to fail. The air/fuel mixture is effected by lack of air pressure. Be prepared to reset the generator as soon as you can safely get to the site. You'll find the generator in 'over crank'. The starter ran too long without turning over the engine. Rather than use up all the energy in the battery, the generator just gives up. Once air pressure returns to normal, all you have to do is reset this and everything should start up.

Another thing can shut down a gen set in a hurricane... over speed. Winds coming in the air exhaust can spin the fan faster than it was designed to rotate. That speeds up the engine. It will shut down due to 'over speed'. Again, same fix: reset the generator as soon as you can get to the site.

Some other hurricane generator failures don't clear as well. Storm surge or even driving rain can flood the generator. Water can get into the fuel if the tanks are water proofed. Are you vents higher than the highest possible water level? Will the fan suck in water?

I spent the first few hours after Andrew just visiting generators at radio sites. In almost every case, a simple press of the reset button cleared the problem. If you have non-technical staff at the sites you might be able to walk them through this over the radio.

 

Cooling Towers:

Another Hurricane related failure to consider: If you have a large chiller plant in your EOC, Fire Station or other important building, how long will the system run without domestic water supply? Power outages and uprooted trees will likely stop the water pressure. How long will the cooling towers run without a water supply? Seems odd to run out of water within hours of a flooding hurricane, but it can and will shut down your cooling if you have cooling towers. Have fresh water available within hours of the storm.  You'll need to know how long you can run with water already in the system and the rate at which water is lost through evaporation and spray.   A clean well might be a good supply.  

 

Flushing:

Another important use for water in your EOC or other important building is flushing of toilets.  Bringing drinking water is easy... getting the toilets flushed is harder.   Again, a clean well might be a solution.  Once you've lost water pressure, you can either wait for the pressure to come back, or pressurize your building with non-potable water.   If you choose the later, this needs to be done carefully.  You'll need to disconnect your building from the public water supply.   Then pressurize the building with water pressure from a well and a pump.  A sprinkler system pump might work.   Cover all water fountains and sinks used for cooling with trash bags since the water is not potable.   If you didn't have time to design and install the backup solution before the water failure, consider the output of the sprinkler pump back fed into the building using one or more outdoor hose connections.   Depending on the size of your sprinkler pump, you might need to leave some sprinklers on to release pressure when there's no water flow into the building.  Remember that a sprinkler pump needs flow to cool the impeller.  If there is a high sand or dirt content in your well water you might need to clean the commercial flush devices if they get stuck on.  

You'll also need to see if you have working sewerage service in your building.   If there's a lift station on your property, is it powered by your generator?   If the lift station fails, how long can you hold sewage before it overflows?   

 

Traffic Signals:

Another thought about power in an EOC, Fire Station or other emergency building:  Are you powering your nearest traffic signal?   In a wide spread power failure, things will be confusing enough.  Will emergency vehicles be able to get in and out of your facility or will they face grid lock?   Granted, one light isn't going to make a big difference in the scope of the whole city, but it's a start.   The current draw of a typical traffic light is far less than 15 Amps at 120 Volts.   It will have little if any impact on your facility.   Just be sure to surge protect the wiring where it enters the building.   

 

Anything else?

If you can think of some other details that should be included here, please let me know.  ray (insert at symbol) rayvaughan (dot) com

09/16/2003

    South Florida FM Association, 2003   
   

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