Utility Manual Flashcards
What does the electrical distribution system include?
Primary and secondary lines
What does the abbreviation K stand for?
1000
Momentary Outage?
Electrical outage lasting two minutes or less
Pothead?
A device which provides transition between underground cable to overhead lines or conductors
Recloser?
An automatic protection device that senses and interrupts distribution system faults
Riser?
The conductor part of transition leading from underground to overhead
Sectionalize?
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
What electrical service is taken at less than 2000 volts?
secondary
Stopcock Valve
a quarter-turn valve used to restrict or isolate the flow of liquid or gas in a pipe
Sustained Outage?
An electrical outage lasting longer than 2 minutes
Time Weighted Average (TWA)?
THe average exposure to a contaminant or condition (such as noise) to which workers may by exposed without adverse effect over a period such as in an 8hr day or 40hr week
What does a vapor density of less than 1 indicate, more than 1?
Less than 1 indicates it is lighter than air while greater than 1 is heavier
What color codes are approved by Virginia State Corporation Commision for underground utilities?
American Public Works Association’s (APWA)
What shall all marks and markers indicate?
Name, initials, or logo of the company that owns or operates the line and the width of the facility if it is greater than 50mm (2in)
Red markings indicate?
electrical, cable, conduit and lighting cable
Yellow markings indicate?
gas, oil, steam, petroleum or gaseous materials
Orange markings indicate?
communications, alarm, or signal lines, cable or conduit
Blue markings indicate?
potable water
Purple markings indicate?
Reclaimed water, irrigation and slurry lines
Green markings indicate?
sewer and drain lines
Pink markings indicate?
Temporary survey markings
White markings indicate?
Proposed excavation
CI stands for?
Cast iron
CPR stands for?
copper
DI stands for?
Ductile iron
PL stands for?
plastic
PVC stands for?
polyvinyl chloride
RFC stands for?
Reinforced concrete
SCC stands for?
steel cylinder concrete
STL stands for?
steel
TC stands for?
terracota
TR stands for?
transite
W/STL stands for?
wrapped steel
What does methane consist of?
carbon and hydrogen
What is the vapor density of methane?
.55
At what times is natural gas not odorized?
In transmission pipelines and rail cars
What is the flammable range for natural gas?
5-15%
What is the ignition temperature for natural gas?
1200 degrees
What is expansion ratio of liquefied natural gas to a gas?
600:1
What is the typical operating pressure of gas lines?
.25-55lbs per square inch (psi)
Gas transmission lines range in size from what to what, and have pressures up to _____, They also can generate ____ to _____ volts of static electricity?
6”-30”, pressures up to 450psi, and 2000-24000 volts
Firefighters should note the following information concerning marking systems for pipelines:
- markers show the pipeline’s approximate location
- signs on the markers list the commodity transported, 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 r how many lines are in the area
- pipelines do not necessarily follow a straight line between two markers
In order to protect pipelines from mechanical damage what is installed at all major vehicular road and railroad crossings?
road casings
What is the trade name for flexible gas line?
Corrugated stainless steel tubing or CSST/Trac Pipe or Ward Flex
If there is a gas leak in a void space where can it be detected?
Around light switches and electrical outlets
What is the proper sequence for shutting off natural gas?
- At the appliance
- At the meter
- At the curb box
What wrench should be used to remove the cover of the street valve?
5 sided wrench
If you cannot manipulate the nut on the cover of a street valve what should be done?
Use a striking tool to break that cast iron cover
Is the curb box connected to the valve?
No it just rests on it
For outside gas leaks what is the standard positioning for engine companies?
Upwind of the hazard area, identify an adequate water supply and position no closer than 100’ for the first arriving unit and a minimum of 300’ for all other incoming fire apparatus
When positioning on a inside gas leak units should take care to avoid parking where?
Next to any side of the affected address
If an outside gas leak line is over what in diameter the incident should be upgraded to a hazmat response?
2”
Besides the leaking gas what is another serious hazard during a leak?
Static electricity
In what situation may fire department personnel crimp or clamp any leaks?
Only in an extreme life saving situation
What is the best course of action if the gas leak if prior to a shut off?
No action
At what depth must a trench be shored?
5’
In order to protect utility company workers, firefighters should position with?
A 20lb dry chem upwind and a charged hose line when necessary
What gas valves should not be operated?
street valves
What is the suggested evacuation distance for gas leaks?
330’
If the FD is going to clamp or crimp a line it must be ____ or smaller.
3/4”
For an outside gas fire what at minimum should be deployed?
1 3/4” line and dry chem extinguisher
If an IDLH atmosphere is identified on an inside gas leak what shall be identified and consideration shall be given to what?
RIT and full structure fire response
When should intrinsically safe equipment be turned on?
prior to entering a gaseous atmosphere
What specific areas must be checked during natural gas leaks?
Upper stories, attics and cocklofts
What is the street pressure of natural gas and what does the regulator reduce it to?
40psi to 1/2 to 1/4 psi
What are the two basic types of gas meters?
inside and outside
When sizing up a building for meters examine all areas of exterior walls near to ground to approx. how high above the ground?
5’
If the gas shut off inside a residential installation cannot be operated due to fire or accessibility where should the gas be turned off at?
curb box
At times when the FD has been called for an inside gas leak and nothing has been found what may be the source of the odor?
Sewer gas from a drain that has not been used recently…the water in the trap may have evaporated and expose the building to sewer gas
What is the expansion ratio of propane?
270:1
What is the vapor density of propane?
1.56
What is the LEL and UEL of propane?
2.3 and 9.5
What does one gallon of liquid propane weigh?
4.23lbs
What is the ignition temperature of propane?
920-1120 degrees
What is the rate mercaptan is added to propane?
one pound per 10,000 gallons of liquid propane which equates to one part per billion
What is the recommended handlines for vapor dispersion?
(2) 1 3/4” lines with nozzles on a narrow fog
The most common propane incident will involve what size cylinder?
20lb cylinder
How many 20lb cylinders are in circulation?
50million
At what point does the relief valve activate on propane tanks?
250psig and 375psig
How much air space does a propane tank need to accommodate changes in ambient temperatures?
20%
Is it safer to have a liquid or vapor propane leak?
Vapor
How many GPM stream can effectively cool a 20-100lb propane tank?
50gpm
What are two indications during a propane tank fire that you should leave immediately?
- Hearing a rising sound from venting safety devices
- Discoloration of the tank
What is the best way to move a propane tank?
Turn it on its side and roll it away
Dangerous amounts of CO can accumulate as a result of:
- Poor installation
- Poor maintenance or failure or damage to an appliance in service
- Fuel is not burned properly
- Rooms are poorly ventilated and the CO is unable to escape
What is the LEL and UEL for CO?
12.8-74%
What is the initial alarm for CO emergency?
1 Engine, 1 EMS unit
At what CO reading shall an occupancy be immediately evacuated and crews shall done SCBA?
35ppm
If your investigation on CO call reveals readings of greater than 10ppm what should to tell the occupants?
Notify them of above normal readings and advise them that they need to have their appliances checked by an approved service rep
As little as how many amps can be fatal?
50milliamps
Define voltage?
Force motivating electrons to flow in a circuit
What is current measured in?
amps or amperes and is the amount of electricity flowing through a wire or conductor
What is the speed of electricity?
186,000miles per second
Define current?
continuous movement of free electrons through the conductors of a circuit
What determines the severity of an electrical shock?
amount of current
What is step potential/ step voltage or ground gradient?
Voltage difference between two points
What does the distribution system for electricity include?
power plants, transmission lines and substations
When power leaves the substation it does so on what lines?
Primary lines
When the power leaves the power plant it travels on?
transmission lines/high voltage lines
How many houses does one transformer normally carry?
10 houses
What is the power line from the pole to the house or business called?
Secondary lines
Secondary lines consist of?
3 lines- 2 insulated that carry the power and 1 un-insulated line which is the netural
How are electrical fires best handled?
Shutting down the power source
What is the most hazardous condition involving power lines?
When the lines do not come in contact with the ground
How far away from a vehicle with downed power lines on it should you stay?
30’
What is the general safe distance rule for power?
1.5x the distance between power poles
If wires are arcing what should personnel do?
Advise their dispatch center of the situation
After the power is removed from a transformer that is on fire what shall be used to extinguish any remaining fire?
Dry chem or CO2
Are firefighters allowed in underground electric vaults, manholes or substations?
Never
What gas is produced and a concern with vault fires located in structures?
CO
When electrical wiring burns in a confined space it gives off large amount of?
CO
What is an interstitial space?
An intermediate space located between regular use floors
What is normally the safest place for FD to lock out power?
Electric panel
What is electrical contact based on?
- Shock intensity
- Path
- Length of contact
If it is not practical to wait for the utility company to arrive on scene after shutting off the service what should be done?
Red utility shut off tag or notification tag and attach it to the affected appliance or lock out
