UTILITY EMERGENCIES April 2014 Flashcards
The flow of an electric current across a gap between two conductors, terminals, or contacts. An ___ can result in sparks, a loud noise, and a momentary or sustained outage as protective equipment operates. An ___ is capable of creating large amounts of heat and light.
pg 1
arc
___ – Short for circuit breaker, a component that detects overload conditions and then disconnects and stops the flow of electrical current to protect and ensure safe operation of the system.
pg 1
Breaker
___ – Acronym for boiling liquid expanding vapor explosion.
pg 1
BLEVE
___ – A path through which electric current is intended to flow. A circuit originates from a central point and extends out to serve customers.
pg 1
Circuit
___ – Located at the top of a utility pole, a wooden bar to which power lines are attached, keeps the lines separated by a sufficient distance to prevent arcing.
pg 1
Cross Arm
___ – The electric distribution system links the transmission system to most customers, includes primary and secondary lines.
pg 1
Distribution System
___ – In an electrical power system, a fault is any abnormal electrical current. For example, a short circuit is a fault in which the current exceeds the normal load. An open circuit fault occurs when some type of failure interrupts a circuit.
pg 1
Fault
___ – A protective device, consisting of a conducting material, which melts and burns opening the circuit when a specified value is exceeded. When melted or blown, the flow of electricity is interrupted to prevent damage to equipment. The temporary disruption of a blown fuse that creates an outage until the fuse is replaced is far better than the type of extended outage that results when equipment is damaged and needs to be replaced. Fuses also limit the number of customers that are affected by the outage.
pg 1
Fuse
___ – Designed to be incapable of producing heat or spark sufficient to ignite an explosive atmosphere.
pg 1
Intrinsically Safe
___ – Actions taken to reroute power around a particular area, leaving it isolated from an energy source while repairs are made.
pg 2
Isolate
___ – Abbreviation for 1,000. (For example, 12 kV = 12,000 volts, 500 kV = 500,000 volts).
K
___ – An electrical outage lasting two minutes or less.
pg 2
Momentary Outage
___ – A device, which provides transition between underground cable to overhead lines or conductors.
pg 2
Pothead
___ – Electric service delivered between 2,000 and 50,000 volts to a distribution transformer, which, in turn, reduces voltage to secondary levels.
pg 2
Primary
___ – An automatic protection device that senses and interrupts distribution system faults.
pg 3
Recloser
___ – The conductor part of transition leading from underground to overhead; may or may not include pothead.
pg 3
Riser
___ – Electric service taken at less than 2,000 volts. Most residential and business customers receive electricity from secondary distribution lines.
pg 3
Secondary
___ – The process of opening switches or fuses to divide a circuit into sections to isolate the cause of the power outage. This reduces the impact of the power outage to the fewest possible customers by allowing power to move through undamaged parts of the system.
pg 3
Sectionalize
___ – A quarter-turn valve used to restrict or isolate the flow of liquid or gas in a pipe.
pg 3
Stopcock Valve
___ – A location, which uses a collection of transformers to reduce voltage and circuit breakers to protect circuits.
pg 3
Substation
___ – An electrical outage that lasts for more than two minutes.
pg 3
Sustained Outage
___ – A device for making, breaking, or changing connections with in an electric circuit.
pg 3
Switch
___ – The process of opening and closing switches to isolate an area from the flow of electricity.
pg 3
Switching
___ – The average exposure to a contaminant or condition (such as noise) to which workers may be exposed without adverse effect over a period such as in an 8- hour day or 40-hour week.
pg 3
Time Weighted Average (TWA)
___ – A device, which transforms electric energy from one voltage level to another level.
Transformer
___ – The transmission system carries electric power at very high voltages, generally between 60,000 and 500,000 volts. It provides bulk transportation of electricity over long distances, usually from generating sources to substations for voltage reduction.
pg 3
Transmission
___ – The ratio of the weight of a given volume of gas or vapor to the weight of an equal volume of air at the same temperature and pressure. A vapor density less than 1 indicates it is lighter than air and will rise; a vapor density greater than 1 indicates a vapor density heavier than air and will sink.
pg 3
Vapor Density
___ – Abbreviation for volt.
pg 3
V
___ – A space underground for electric cables, transformers, and other parts of the underground electric system.
pg 3
Vault
___ – The unit of measure of electric potential, which is the condition that causes electric energy to flow.
pg 3
Volt
Flammable limits are a range of concentrations over which, a flammable gas or vapor, mixed with air will burn if an ignition source is present.
- Below the LEL, the mixture is ___ (or has too much oxygen and not enough fuel) and cannot burn.
- Above the UEL, the mixture is ___ (or has too much fuel and not enough oxygen) and cannot burn.
pg 4
too lean & too rich
___ (paint or a similar coating) should be used to indicate the locations and route of buried lines. To increase visibility, color-coded vertical markers (temporary stakes or flags) should supplement surface marks.
pg 6
Color-coded surface marks
All marks and markers should indicate the name, initials, or logo of the company that owns or operates the line and the width of the facility if it is greater than 50 mm (2 inches).
APWA Color Codes
- RED electric, cable, conduit, and lighting cable
- YELLOW gas, oil, steam, petroleum, or gaseous materials
- ORANGE communications, alarm, or signal lines, cable or conduit
- BLUE potable water
- PURPLE reclaimed water, irrigation and slurry lines
- GREEN sewer and drain lines
- PINK temporary survey markings
- WHITE proposed excavation
pg 6
APWA Color Codes
- RED electric, cable, conduit, and lighting cable
- YELLOW gas, oil, steam, petroleum, or gaseous materials
- ORANGE communications, alarm, or signal lines, cable or conduit
- BLUE potable water
- PURPLE reclaimed water, irrigation and slurry lines
- GREEN sewer and drain lines
- PINK temporary survey markings
- WHITE proposed excavation
___ is a simple hydrocarbon consisting of carbon and hydrogen
pg 8
Methane
___ in gases is defined as the weight of a given volume of gas compared to the weight of the same amount of air at the same temperature and pressure
pg 8
Vapor density
The flammable range for natural gas is between ___% and ___%.
pg 8
5 & 15
The ignition temperature for natural gas is about ___° F and can easily be ignited by something as simple as a doorbell or a cell phone
pg 8
1200
___ remain the safest, most efficient, and economical way to move these natural resources.
pg 9
pipelines
Any of the following events along the pipeline easement could indicate a ___:
- A hissing or roaring sound.
- Any unusual odor near the pipeline.
- Dead or discolored vegetation in an otherwise green location.
- Fire coming from the ground or appearing to burn above the ground
- Dirt being blown or appearing to be thrown into the air.
- Water bubbling or being blown into the air at a pond, creek, or river.
- A dry spot in a moist field.
pg 9
pipeline leak
Firefighters should note the following information concerning ___ for pipelines:
- Markers show the pipeline’s approximate location; not its exact location.
- Signs on the markers list the commodity transported, the name of the pipeline company and a telephone number where company representatives can always be reached.
- Markers do not indicate how deep the pipeline is buried or how many lines are in the area.
- Pipelines do not necessarily follow a straight line between two markers.
pg 10
marking systems
To protect the pipeline from mechanical damage, ___ are installed at all major vehicular road and railroad crossings
pg 11
road casings
The proper sequence for shutting off the utility in either a leak or fire situation is as follows:
pg 12
- At the appliance (if can be safely done).
- At the meter.
- At the curb box.
When shutting off the gas at the appliance, the shut off valve will be a quarter turn, just prior to the regulator and appliance that it is serving
When shutting off the gas at the meter use a wrench or Halligan tool to turn the quarter-turn valve.
When performing a shut off at a curb valve, use the five-sided wrench to remove the cover of the street valve
Commercial gas meters are usually much larger and operate at higher pressures than residential meters. Turning off the wrong valve may create a more serious problem. Commercial occupancies may have several valves. The valve to shut off is the one located ___ to the regulator.
pg 13
prior
Natural Gas Emergencies
The general rule for apparatus positioning for natural gas emergencies is no closer than ___ feet for the first arriving unit and a minimum distance of ___ feet for all other incoming fire apparatus
pg 13
100ft & 300ft
Other responding equipment shall stage upwind and prior to the affected area and await an assignment from the initial engine company officer
Natural Gas Emergencies
The second engine should stage at a hydrant ___ the hot zone and await the orders of the initial crews before taking any action.
pg 14
outside
If later arriving apparatus is approaching the scene from a different direction of travel they should stage prior to the dispatched address to avoid traveling through the hazard zone
Crews should avoid parking their vehicles over sewers, valve covers, and manhole covers because the collection of gases in these locations could present a potential hazard to first responders.
An ___ is defined as any flammable gas leak that has originated outside a structure and the gases have not migrated into the building of origin or exposures nearby.
pg 14
outside gas leak
If the break is in a line that is reported to be over ___inches in diameter, the incident should be upgraded to a hazardous materials response because of the increased risk of large amounts of escaping flammable gases.
pg 14
2” inches
The initial alarm assignment for outside gas leaks not meeting the criteria for a hazardous materials response should consist of the following as a minimum:
pg 14
- 1 engine company
- 1 truck or rescue
For Outside Gas Leaks:
The ___ has the responsibility of providing ventilation, when necessary, metering, investigation of exposure, and assisting the initial crew with their assigned tasks
The officer of the ___ shall re-con the scene to determine the location and extent of the leak through an on-scene supervisor, contractor, or the person who reported the leak.
pg 14
specialty piece & first-arriving unit
Another serious hazard during a leak is the ___ (up to 24,000 volts) that is building up in the leak area as the gas escapes.
pg 14
static electricity
It is recommended that no fire department personnel crimp or clamp any leak unless it is an ___ situation
pg 14
extreme life-saving
In most cases if the leak is prior to ___:
- No gas is entering any structure and is dissipating into the atmosphere.
- The best course of action is no action.
- Don’t cover any pipe that is leaking and do check for migration of gas in surrounding buildings, basements, and sewers.
- Set up a hot zone, wait for the utility company to arrive, and let them mitigate the leak.
pg 15
a shut off
Fire department personnel shall ensure no persons enter a trench deeper than ___’ feet that is not shored (29 CFR 1926.651)
pg 15
5’ feet
To protect the utility company workers, units should position upwind with a 20lb. ___ and a ___ when necessary.
pg 15
dry chemical extinguisher and charged hose line
For Outside Gas Leaks, The DOT Emergency Response Guide (ERG) suggests an evacuation distance of ___ft.
pg 16
330 feet
In situations where you cannot find the leak, use a ___, to help pinpoint the source in piping and meters
pg 16
soapy water spray
Only in extreme cases would fire department personnel perform clamping or crimping a leak. This should only be considered for lines that are ____
pg 16
3⁄4” or smaller
- Several feet from the leak, dig a hole to expose the leaking line away from any gas readings. Gas lines are buried around 24” below the surface but it is not uncommon to find them only several inches to several feet deep. With plastic pipe, the gas company lays a yellow-coated wire over the gas line so their detectors can find the metal; the detectors cannot pick up the plastic pipe. Sometimes you may find a yellow banner tape above the line to give warning that the pipe is below.
- Once this gas line is exposed, use a grounding spray or grounding device such as a wet towel over the pipe to ground and then safely clamp the line.
The use of ___ and/or ___ should take into account the wind direction, humidity, weight of the gas, and any other factors pertaining to the migration of the vapor cloud.
pg 17
hand lines and/or dry chemical extinguishers
For burning gas meters, it will take a coordinated effort of ___ to extinguish the fire while providing protection for a firefighter to shut off the gas at the ___ on the meter,
pg 18
two hoselines deployed on wide-fog patterns and stop cock
When the gas meter is involved, and access to the meter shut off cannot be accessed, the best place to shut off the gas is at the curb valve
The initial alarm assignment for inside gas should consist of the following as a minimum:
pg 19
- 2 engine companies
- 1 truck or rescue
- 1 Battalion Chief
If any occupants report feeling ill an EMS unit shall be added.
When an IDLH atmosphere is identified, an initial RIT shall be identified and consideration shall be given to increasing resources for a structure fire response.
Inside Gas Leaks
The ___ re-con the scene to determine the location and extent of the leak through an on-scene supervisor, contractor, or person that reported the leak and determine the resource requirements for mitigation and call for any additional needs as soon as possible and stage resources away from immediate area.
pg 19
officer shall
Where concentrations are the highest, ventilation should be started immediately
Opening a door or venting an atmosphere that is above the Upper Explosive Limit (UEL) could cause an explosive atmosphere and subsequent explosion.
If the power to a structure is shut off at the electric panel this action may cause the generator to operate. Secure the generator prior to operating the electric panel.
The key to turning off gas service in any structure is locating the regulator. The regulator takes street pressure of up to 40 psi and steps it down to somewhere between ___ psi prior to the meter.
pg 21
1⁄2 to 1⁄4 psi
the presence of a gas vent on an exterior wall is an indication of an ___.
pg 22
inside gas meter.
Firefighters shall not attempt to shut off gas service by operating valves in ___ or ___. Only utility company personnel should operate these valves. Operating valves located in street boxes and manholes may actually increase pressure to customer service.
pg 23
street boxes or manholes
In single-family installations, a ___ is usually located in the front lawn between the sidewalk and street, or located in the driveway or sidewalk leading to the residence.
pg 23
curb box
___ is a fossil fuel that is found mixed with natural gas and petroleum deposits in rocks deep underground
pg 25
Propane
Propane has an expansion ratio of 270:1
The vapor density of propane is 1.56
Propane has a LEL of 2.3 and an UEL of 9.5
One gallon of liquid weighs 4.23 pounds.
Propane has an ignition temperature between 920° F and 1,120° F.
For Propane Emergencies
Engine companies shall position the apparatus ___ of the hazard area if at all possible and determine the most efficient water supply.
pg 25
prior to and upwind
The other responding units shall stage upwind and prior to the affected area and await an assignment from the engine company or Incident Commander.
___ should be based on monitoring data, wind direction, terrain, and size of the leak.
pg 25
Evacuation decisions
Earth probes should be used to determine if gas escaping and caused the problem.
It is recommended that two 13⁄4” hoselines with the nozzles on a narrow fog pattern be deployed for vapor dispersion
The relief valve is designed to operate and release pressure when the internal pressure exceeds ___ psig and ___ psig depending on the size of the tank
pg 26
250 and 375
A 20 to 100 lb tank can be effectively cooled with a ___ gpm stream. The initial attack line should be the 1 3⁄4” line along with an additional backup 1 3⁄4” line.
pg 26
50
If you are fighting a propane fire and you hear a rising sound from venting safety devices or see discoloration of the tank ___ immediately.
pg 26
leave the area
In structures where propane is used to service the major household appliances these types of leaks can be handled like inside natural leaks with the major exception of the LPG being heavier than air and will seek lower areas of the structure. The best place to turn off the gas is ___ from the outside of the structure.
pg 27
at the tank
___ is formed by the incomplete combustion of the fossil fuels – gas, oil, coal, and wood used in boilers, engines, oil burners, gas fires, water heaters, solid fuel appliances, and open fires.
pg 28
Carbon monoxide (CO)
CO is flammable and has a wide explosive range. The LEL for carbon monoxide is 12.8% and the UEL is 74%.
In terms of parts per million (ppm) carbon monoxide’s explosive range would equate to 128,000 on the LEL and 740,000 on the UEL.
recommended initial alarm assignment for carbon monoxide emergencies is:
pg 28
- 1 engine company
- 1 EMS unit
___ is an odorless, tasteless, colorless gas that is deadly. It is a by-product of a fuel burning process.
pg29
Carbon monoxide (CO)
If the detection/monitoring equipment shows a reading of 35 ppm or above, the occupancy shall be immediately evacuated and crews should retreat from the structure and don their SCBA face piece before making reentry.
During the investigative stage, the occupancy should not be ventilated, ignition sources should be eliminated, and the source of the CO located
It is not uncommon to have CO levels up to ___ ppm in a structure.
pg 29
10
Electricity has two basic properties:
pg 31
voltage and current.
The force motivating electrons to flow in a circuit is called voltage – it is the pressure or force driving the electric current through a wire or other conductor.
Voltage is a specific measure of potential energy that is always relative between two points.
Current is measured in amps or amperes and is the amount of electricity flowing through a wire or conductor.
Electricity travels at 186,000 miles per second, which is the speed of light.
A ___ allows the flow of electricity-low resistance that completes the path or circuit.
pg 31
conductor
The voltage difference between two points is called ___, ___ or ___.
pg 32
step potential,
step voltage, or ground gradient.
The power lines from the pole to a house or business are called ___. These lines normally consist of three lines. Two are insulated that carry the power and an un-insulated line, which is the neutral.
pg 35
secondary lines
The primary lines are supposed to be buried 30” to 36” below grade
The secondary lines are to be 24” below grade
The safest insulator for electricity is ___.
pg 35
distance
The most hazardous conditions involving power lines are where the lines do ____
pg 36
not come in contact with the ground.
To assist the utility company in pinpointing the exact area of the issue, personnel shall provide a ___ from a safe location to the dispatch center. Pole numbers in Northern Virginia typically have two lines of numbers posted on the pole.
pg 36
pole number
Water should not be used to control pole top fires unless they have been de-energized by the power company. ___ and ___ may be used to extinguish some fire. Exposure protection is paramount.
pg 37
Dry chemical and CO2 extinguishers
Ground transformers.
___ and/or ___ should never be opened prior to the power being turned off and confirmation from utility company representative on the scene. If opened, they may cause an explosion due to the accumulation of flammable gases. After power is removed it is recommended to extinguish any remaining fire with dry chemical or CO2 extinguishers
pg 38
Doors and/or shutters
___ should never be allowed to enter underground electric vaults, manholes, or substations.
pg 39
Firefighters
Similar to an exterior vault, personnel should not enter any vault until the utility company confirms off the power
To be proactive, crews can ventilate the building while awaiting the power company if the ventilation will not draw fire towards uninvolved areas. ___ will reduce the probabilities of a CO explosion.
pg 40
Ventilation
All personnel shall use breathing apparatus while operating at a transformer fire.
Firefighters should stay clear of manhole covers over underground electric vaults; these have been known to blow off and fly as far as ___ feet.
pg 41
150
An ___ is an intermediate space located between regular-use floors, commonly located in hospitals and laboratory-type buildings to allow space for the mechanical systems of the building.
pg 41
interstitial space
Normally the ___ is the safest place for the fire department to lock out the power.
pg 43
electric panel
___ and ___ occupancies may have numerous large switching devices; qualified personnel should only operate these large devices.
pg 44
Mercantile and multi-residential
A certified representative from the power company should only do this procedure.
When navigating in poor visibility, firefighters should when appropriate ___, allowing muscles to contact inward and away if they come in contact with electric wires.
pg 44
keep their arms up and palms in
Before raising or extending any ladder on the scene the overhead must be checked for power lines. With enough voltage the ladder doesn’t need to actually contact the wire to become energized.
The body conducts electricity due to ___. Electrical contact is based on shock intensity, path, and length of contact
pg 44
moisture
In the event of a water emergency, firefighters may elect to close the main supply valve where it enters the structure. The main supply valve can typically be found in ___ or ___.
pg 46
the basement or utility room
Water can also be shut off at the street by closing the valve at the meter in the curb box.
The presence of an armored ground cable attached to a water pipe extending from the electric meter can assist in identifying the ___.
pg 46
main supply line.
If no electrical emergency exists, personnel can mitigate the presence of water in the ___ by:
- Locating a floor drain (basement sink or shower stall) and removing any debris around the drain will assist in the removal of water.
- Remove the toilet bowl, if present, as this will allow water to drain from the floor area and out of the structure if this drain is not the source of the flood.
- Clearly mark and announce any drain you clear or any toilet you remove to prevent any persons from getting any part of their body sucked into the drain.
pg 46
basement
Any time the fire department shuts off utility service, the ___ must be notified.
pg 46
utility company
If it is not practical to wait for the utility company to arrive on scene, the unit officer shall fill out a red utility shut off tag or notification tag and attach it to the affected appliance or lock out.
If the fire department must also turn off a sprinkler system to a commercial building, proper notifications to the ___ or ___ in the jurisdiction of the affected structure shall be made.
pg 46
fire inspection division/department or fire marshal’s office
