NETA Level 2
NFPA 70 defines work space condition ____ as having live parts on one side and grounded parts on the other side
2
Radial system with primary selectivity
2 feeds feeding switches to choose which feeds the main bus (this can be used with an ATS)
primary selective system
2 primary breakers feed 2 busses connected by a tie breaker that is usually open
Which device functions when the circuit admittance, impedance or reactance increases or decreases beyond predetermined limits?
21 Distance relay
What size cable would you expect to find on ASTM Grade 4 personal protective grounds?
3/0 AWG
How much torque is required to produce 300 HP at 4600 RPM?
343 lb-ft HPx5252/rpm=torque
A given 120VAC 60Hz circuit has a load of 10A with a 20� lagging power factor for 30 minutes. What is the reactive power?
410.42 VAR 120V*10A=1200W*sin(20)=410.42 VARs
Which protective relay functions on a predetermined value of polyphase voltage in the desired phase sequence?
47
Point to point results on new grounding systems in a generating station that exceed ______ should be investigated
500 milliohms
What is the insulation resistance test voltage for emergency generator for windings rated at 480V line to line
500V
A delta-wye transformer has a turns ratio of 9:1. The primary line voltage is 3600 V. What is the secondary line voltage?
692.8 V
What is the NETA-ATS recommended test voltage for hipot testing a 3-phase, 34.5kV automatic circuit recloser with a rated impulse withstand voltage of 150kV?
70kVAC Test Voltage = Operating Voltage*2+1000V VDC = VAC*1.414
The maximum voltage of an industrial multimeter without a high voltage probe is typically
750-1000V RMS - Non Continuous
What is the expected contact-resistance measurement for a 4000A 480V air circuit breaker in good condition?
8-24 microhms
Which of the following would best describe a transformer?
A device that changes voltage and current levels
Which of the following is not a form of respiratory protection defined in OSHA 1910:
APFR
Which of the following circuits cannot be grounded:
All of the above
Boundary least to worst
Arc flash boundary limited approach boundary restricted approach boundary prohibited approach boundary
Which NFPA 70E article covers placing equipment in an electrically-safe work condition?
Article 120
What type of switch is required for an incoming service of 3000-4000A?
Bolted-Pressure Switch
A wire wound on a metal pipe will have which of the following:
Both resistance and inductance
What does CPR stand for?
Cardiopulmonary Resuscitation
Oxidation of copper contacts will be severe in areas, which contain?
Chemical fumes
Apparent Power
Circuits Impedance (Z)
Reactive Power
Circuits Reactance (X)
OSHA 1910.146
Confined Spaces
Power Factor
Cos Theta
CO-6 curve by IEEE standrard
Definite Minimum
Which of the following protection element tests would you most likely NOT perform on a new 21 device?
Determine time delay
Which of the following ground fault detection methods involves sensing current in only one conductor?
Direct method
Which of the following is not a rule of thumb when concerning arc flash
Each layer of under arc-rated clothing reduces the heat to the body by 50%
OSHA 1910.334
Electrical Use of Equipment
OSHA 1910.333
Electrical Use of Work Practices LOTO
OSHA 1910.137
Electrical protective devices
Direct-current bus arrangement must be arranged positive to negative from front to back, top to bottom, or left to right, as viewed from the front of a switchboard, switchgear, or panelboard.
False
Medium-voltage cable, in accordance with NEC Article 328, is defined as single or multiconductor solid dielectric insulated cable rated at 2000 volts or higher for use on power systems rated up to 35kV.
False
Unbroken busway lengths shall not be extended through drywall
False
Wiring diagrams should show all components in a circuit, arranged without regard to their actual physical location.
False
The main breaker and the feeder breakers all have instantaneous trip functions in the overcurrent trip devices. Which of the following statements is true?
Feeder breakers and/or the main breaker may trip
OSHA 1910.155
Fire Protection
Which of the following would be a factor in choosing between 100%, 133%, and 173% Medium voltage cable for a power system?
Ground Fault Protection
After a conductor or circuit part has been deenergized and Lockout-Tagout (LOTO) applied and verified, which of the following is the best way to release stored energy?
Ground the conductor or circuit part
OSHA 1910.138
Hand Protection
OSHA 1910.147
Hazardous Energy Control
Resistance Reactance Impedance Triangle
Hypotenuse = Impedance Z^2=R^2+X^2
Power Triangle
Hypotenuse is Apparent Power
Partial discharges are created by:
Ionization of air pockets within the insulation
Oil SG less than 1 where do I pull the sample
Less than 1 means it is less than water and will float to the top which means we should pull the sample from the bottom
Ground fault protection system is provided for the protection from line to line ground faults that occur on the _____ of the service disconnect means.
Load side
What does LEL stand for?
Lower Explosive Limit
Primary and Secondary Simple Radial System
Main breaker feeds secondary feeder breakers that go to loads.
What does NERC stand for?
North American Electric Reliability Corporation
Power transformer cooling classes went through major changes in the United States when IEEE Standard C57.12.00-2000 adopted the modern four-letter designation. Which of the following old designations does not match the new?
OA/FOA = ONAN/ONAF
Radial System Electrical
One primary fused switch and Transformer to feed a main bus
Expanded Radial system
One utility breaker feeds 2 xfmr's and 2 busses
A drawing the principally shows the flow of electrical power is a what
One-Line
Which portion of the transmission system experiences faults occur most frequently?
Overhead lines
OSHA 1910.134
PPE/Respiratory Protection
OSHA 1910.157
Portable Fire Extinguisher
You walk up to a transformer to obtain an oil sample. What is the first thing you should check before opening the drain valve?
Pressure gauge
Primary Loop system
Primary main breaker feeds parallel to two loop feeders and both loads can be fed by either breaker hence the loop
An electrical system that is not typically used in an industrial application
Redundant system
True Power
Resistive element
OSHA 1910.269
Special Industries, Electric Power Generation, Transmission, and Distribution
OSHA 1926.1053
Stairways and ladder
When performing atmospheric tests on a confined space:
Test oxygen level first
Solar photovoltaic systems, fuel cell systems, wind electric systems, energy storage systems, or interconnected electric power production sources are permitted to be connected to the supply side of the service disconnecting means
True
OSHA 1910.23
Use of Ladders
OSHA 1910.25
Use of Scaffolding
Arc Flash Boundary
Where a person can receive 2nd degree burns
3 capacitors: 12, 20, and 30micro farads are connected in series to a 400Hz source. The total Xc is what?
Xc=1/(2)(Pi)(f)(F) Xc=1/(2)(Pi)(400)(6x10^-6)= 66.31 ohms
The safety glasses or goggles suitable for electrical work should
be non conductive
The amp rating of the trip device in a breaker is the
continuous current rating
Which of the following relay is provided as the primary protection of transmission lines:
distance
The training required by NFPA 70E for electrical safety shall be:
either in classroom or OTJ
Polarized capacitors are also known as _____ capacitors.
electrolytic
What does a kilowatt-hour meter read?
energy use
What is the primary advantage of sulfur hexafluoride gas as an insulator?
its insulating strength increases with pressure
Dielectric strength of SF6 is
less than that of oil used in OCB
The smallest particle of a substance where it still retains it�s properties is a/an______.
molecule
Oil SG greater than 1
pull sample from top since the water will be able to float on top of oil
The isolating switch installed near disconnecting means shall be accessible to only
qualified persons only
A ________ rated switchboard has a main circuit protection device that is equal to or greater than the available fault current, but subsequent downstream circuit protection devices connected in series have a lower interrupting rating.
series
Ungrounded service conductors between the terminals of service equipment and service conductors are what
service entrant conductors
A face shield has 11 cal/cm^2 rating on it. What does this mean
you have a 50% chance of receiving 2nd degree burns on bare skin
XL
(2)(Pi)(f)(L)
Class 00 gloves BRWYGO
(BEIGE) max use 500VAC tested at 2500 VAC
Class 3
(GREEN) Max use 26,500 VAC tested at 30,000
HP Torque equation
(HP*5252)/(RPM)=Torque
Class 4
(ORANGE) max use 36,000VAC tested at 40,000
Class 0
(RED) max use 1000VAC tested at 5000
Class 1
(WHITE) max use 7500VAC tested at !0,000
Class 2
(YELLOW) max use 17000VAC tested at 20,000
write three thousand fortyeight tenthousanths in decimal form
0.3048
PPE levels
1- 4cal 2- 8 cal 3- 25 cal 4- 40 cal
Xc=
1/(2)(Pi)(f)(C)
Atmospheres that contain a flammable component above what percent of its Lower Explosive Limit (LEL) are considered hazardous for confined space entry?
10%
If a current of 30 amps is measured with a 100 amp 3% ammeter, the maximum possible error in terms of actual error is:
10%
What is the maximum deviation allowable between fuse resistances in a new medium-voltage motor starter?
15%