WorksheetsTest 2
Total questions: 51
Worksheet time: 38mins
Which one is a not symmetrical fault?
Line to line
Line to neutral
Line to ground
About … percent of faults ate double line to ground
20
30
25
Flashover causes insulator to lose their insulating
Resistivity
Conductivity
Capacity
Types of open circuit faults?
One, two, three conductor open
Five, Six conductor open
Three phase short circuit fault
Three phase to ground fault
Weather condition includes...
Medusa
Lighting strikes, heavy rains, heavy wind, salt diposition ice and snow accumulation
Bad frequency
Unbalance
Types of faults in electrical power system?
Lockdown
Transformer breakdown
Open circuit and Closed circuit which also includes symmetrical and unsymmetrical faults
Insulation resistance fault
The L-L-L-G fault occurs between the three phases and earthing of the system.
True
False
Flash over from arc fault causes insulators to lose their insulating capacity due to high resistance.
True
False
About 20 percent of faults are ________.
Single line to ground
Double line to ground
Line to line
Three phase short circuit
How many types have «open circuit fault»?
3
2
4
Can weather conditions damage to power supply?
Yes
No
Called 3 types of symmetrical faults?
L-G, L-L, LL-G.
L-L-L
L-L-L-G
In unsymmetrical faults, about ___% of of faults are _____ faults.
25%, L-G
23%, LLL-G
20% LL-G
None of the above
The location of the grounding is between the equipment body and earth pit which is placed under the surface.
True
False
Electrical faults is ___ of voltages and currents from nominal values
Deviation
Occurrence
Reason
None of the above
… - water resistant *Protected against water jets from any angle
IP 67
IP 65
IP 68
The extent of injury accompanying electric shock depends on
The amount of of current conducted through the body
The path of the current through the body
The length of time a person is subjected to the current.
All of them above
When the human gets electrical shock with wet skin how the will feel painful shock?
400 to 600 ohms
100.000 to 600.000 ohms
1000 ohms
OSHA is...
Occupational safety and health access
Occupational safety and human administration
Occupational safety and health administration
IP68...
Water resistant in fresh water, maximum depth about 1.5m, protected from dust
Water resistant in fresh water depth not less than 1.5m not protected from dust.
Protection against close range, high pressure and high temperature spray.
Never operate electrical equipment in..
You can operate everywhere
Wet location
Dry location
What are two types of fault in the electrical power supply system?
Phase circuit fault | Neutral circuit fault
Open circuit fault | Close circuit fault
Symmetrical fault | Unsymmetrical fault
None of the above
The power system operates under the...….
Weather condition
Climate condition
Balanced condition
Unbalanced condition
What means the «NFPA»?
National Fire Policy Act
National Form Pilots Association
National Fire Protection Association
None of the above
What tools are used during operation to avoid electric shock?
Metal
Isolated
Plastic
How many main types of power system fault?
3
4
2
5
Which ladder cannot be used during electric shock?
Aluminum
Wood
Plastic
High
When the human body will feel painful shock?
At 30 to 75 mA
At 10 to 30 mA
Over 4 Amps
At 3 to 10 mA
What doesn't apply to an electric instrument?
Milling machine
Chisel
Miter Saw
Grinder
Fault.... And analysis is necessary to.... or design suitable switchgear equipments, ... relays, circuit breakers and so on.
detection/search/electromechanical
deviation/select/electronic
detection/select/electromechanical
detection/select/electrostatic
A power system operates under …
Balanced condition
Unbalanced condition
None balanced condition
None of them
How many mainly types of faults in power system
1
4
3
2
How many percent system faults in symmetrical faults
0-1%
8-10%
2-5%
5-7%
What color of the wire has the grounding?
Green
Yellow
Black
White
From what level of current do serious consequences to the human body begin?
50 mA
40 mA
30 mA
20 mA
Decoding the word OSHA
Occupational safety and Health Association
Occupational Safety and Hygiene Administration
Occupational Safety and Health Administration
Occur Safety and Hygiene Association
Before the work, use a __________ when applying electrical safety practices in your workplace
Manual
Guide
Instruction
Checklist
Which fault is it: Ionization of air, surrounding the overhead lines results in spark between the line.
Human errors
Weather conditions
Smoke of fires
Equipment conditions
Which of these options can be classified as Open Circuit Fault?
Three conductor fault
Three phase to ground fault
Single line-to-ground fault
Line-to-line fault
What is a Digital Checklist?
Is a tool that serves as a guide when performing work on hazardous facilities
Is a special line that runs in the power plants from the substation
Is an instrument which measures amount of electrical energy used by the consumers
As a result, what causes Malfunctions in the power system like lightning, strong wind, earthquakes?
This leads to the flow of excessively large currents, and damage to the equipment.
This consequence leads to a fire of devices and equipment
All correct
The most common fault or malfunction is
Line to ground (L-G)
Line to line (L-L)
Line to line to line (L-L-L)
Other name of arc flash
Flashover
Flash arc
Arc
None of them
What does it mean (L-L-L-G)
Line to line to line to ground
Line to line to ground
Line to line
Line to ground
A power system operates under ______ ________
Balanced conditions
Weather conditions
Wet conditions
None of them
Electrical Fault is the … of voltages and current
Normal condition
Deviation
Equipment
Protective device
Why the system become unbalanced and occurs short-circuit?
Failures of insulation
Contact of live wire
All correct
None of them
How many categories NFPA 70E breaks protective clothing and PPE down?
5
2
4
3
Types of open circuit faults: Single conductor open, Double line conductor open, Three conductor open.
True
False
How many percent of system faults are symmetrical faults?
2.5 percent
2-5 percent
2-2.5 percent
2 percent
Ionization of air, due to ______ particles, surrounding the overhead lines results in spark between the lines or between conductors to insulator. This ________ causes insulators to lose their insulating capacity due to ____ voltages. Put the missing words into the gaps.
Burn, arc, low
Smoke, light, high
Smoke, flashover, low
Smoke, flashover, high
