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