3rd year final

True or False: A solidly grounded system is one where one of the current-carrying conductors is intentionally connected to the earth.

True

True or False: Employers who exercise "due diligence" is an employer who is proactive with regard to safety.

True

A 2000-A switchgear is fed from a transformer with five parallel sets of 600 kcmil wire in five parallel conduits. ____ AWG or kcmil is the smallest system bonding jumper permitted for this installation. A. 400 B. 3/0 C. 600 D. 250 E. 1/0

A. 400

In terms of grounding, the earth is considered to represent ____ A. Zero potential B. A natural battery C. Negative polarity D. Infinite impedance

A. Zero potential

Feeders are required to be ground-fault protected if the system is 480-volt, three-phase, wye connected and above ______ amperes. A. 600 B. 1000 C. 1200 D. 1500

B. 1000

A 208/120-volt, 3-ph, 4-wire panelbaord will be fed with one conduit. This service panel contains a 200-Amp main breaker. The conductors supplying the service will consist of three 4/0 AWG ungrounded conductors (one for A phase, one for B phase, and one for C phase) plus a grounded conductor. The calculated neutral load is 90 amps. The smallest neutral that can be run is a ____ AWG A. 4 B. 2 C. 6 D. 8 E. 3

B. 2

In a 277/480-volt, 3-phase, 4-wire system, the maximum voltage to ground is _____ A. 120 volts B. 240 volts C. 208 volts D. 277 volts E. None of these

D. 277 volts

Tags used for lockout/tagout may include: A. The name of the worker who placed the tag B. The phone number of the owkrer who placed the tag C. The length of time the equipment is expected to beo ut of service D. All of the above

D. All of the above

____ can be used to connect grounding conductors and bonding jumpers. A. Exothermic welding B. Listed pressure connectors C. Listed clamps D. Any of these

D. Any of these

The NFPA 70E recommends ______ training for electrical workers. A. Instructor led classroom B. On the job C. Computer based D. Both a and b

D. Both a and b

A 600-amp main breaker service panel will have a 225-A breaker installed in it to feed a 225-amp, 1 phase, 3-wire main breaker panel. You will install three 4/0 conductors to the new panel. You will install a _____ AWG MBJ in this new 225-amp panel. A. 2 B. 4 C. 3 D. none of these

D. none of these

Where the main bonding jumper is a screw only, the NEC requires that it be identified with _____ I. A green finish, visible when the screw is installed II. A hexagonal head III. A listing mark, visible when the screw is installed

I only

Which of the following conditions would be classified as an overload? I. 43-A noncontinuous load connected to a 40-A fuse II. An undgrounded conductor touching a grounded conductor III. An ungrounded conductor touching a grounding conductor

I only

NEC Sections 250.20, 250.21, and 250.22 state when a system is required, permitted, or not permitted to be grounded. Which of these transfoerm secondares is REQUIRED to be grounded? I. 120 to 12-volt AC transformer for a low-voltage lighting system II. 480 to 120/240-VAC, 1 phase, 3-wire to a panelboard III. 480 to 120-VAC for a motor control circuit

II & III only

If you were to touch an energized ungrounded conductor and a grounded surface, _____ I. The circuit breaker will trip II. You will be shocked

II only

As ciruit resistance _____, the time it takes for an OCPD to operate increases.

Increases

True of False: A transformer is supplied by a 277-volt circuit. The transformer delivers 120 volts for use in a control circuit. On of the two 120-volt wires is required by the NEC to be grounded.

True

True or False: A qualified person must be trained in the skills and techniques to determine nominal voltage.

True

The __ is the distance from exposed energized conductors or circuit parts where bare skin would receive the equivalent of 1/2 cal/cm2 A. Arc Flash Boundary B. Limited Approach Boundary C Prohibited Approach Boundary D. Restricted Approach Boundary

A. Arc Flash Boundary

The "hot" conductors, neutral conductors, switch legs, travelers, and equipment grounding conductors of a branch circuit are installed together in the same conduit in order to avoid_______ A. Induction heating B. Potential differences C. Inductive reactance D. All of the above

A. Induction heating

An air-conditioner condenser unit was supplied with a 240-volt circuit that was run in PVC. The circuit originates in a 120/240-volt, 1-ph, 3W service panel. Only two "hot" conductors were installed in the PVC. The A/C unit is contained in a metal enclosure. You found that the grounding lug on the unit was tied to a ground rod that was drive next to the unit. Is the NEC satisfied with this grounding arrangement? A. No B. Yes

A. No

A 120-volt load is operating when you open the neutral in a j-box. If you touch the neutral from the load with your left hand and the grounded metal conduit with your right hand, your body would be in _____ with the load A. Series B. Parallel

A. Series

A three-phase, four-wire, delta-connected system in which the midpoint of one phase winding is grounded is often known as a "delta with a high-let." Where installed in a panelboard, NEC section 408.3 (E) requires which phase to be the high-leg? A. A B. B C. C D. N

B. B

Cicuits HA-1, -4, and -11 with a neutral have been pulled in EMT from a 277/480-volt, 3 phase, 4W panelboard to some high-bay luminaires that have been installed in a warehouse. If the wire from breaker 4 comes in contact with the neutral, _____ will occur. A. A Ground Fault B. A Short Circuit C. A backfeeed

B. A short circuit

20-amp circuits LA-1, -4, and -11 with a neutral have been run as 4-wire, 12 AWG MC cable from a 120/208-volt, 3 phase, 4W panelboard to a junction box. Fluorescent luminaires have been installed in several offices in a business and connected to these circuits. The offices will be used continuously during the business day. Each luniaire draws 1.3 ampls. If 15 luminaires are connected to Ckt. LA-4, the circuit breaker will _______ A. Operate within its ratings B. Be overloaded

B. Be overloaded

The primary method required by OSHA for protecting qualified electrical workers from electrical hazards is: A. Equipment shutdown B. Lockout/tagout C. Posting signs D. Using appropriate PPE

B. Lockout/tagout

You connected the GEC to the copper main water service pipe above the ceiling. The plumber later disconnected it and has left it disconnected. Because of this, if a "hot" branch circuit conductor contacts the EGC installed with that circuit, the branch-circuit breaker will _____ A. Take approximately 2 seconds longer than normal to trip B. Operate as it should C. Take more than 3 times the normally required time to trip

B. Operate as it should

The purpose of grounding the main bonding jumper is to _____ A. Minimize shock hazard B. Provide an effective path for ground-fault current C. Lead stray currents away from the equipment D. Minimize static electricity

B. Provide an effective path for ground-fault current

All equipment grounding conductors and grounding buses in service panels must be _____ A. Insulated from one another B. Painted or marked green C. Bonded together D. Marked with white tape

C. Bonded together

NFPA 70E requires that the contract employer inform its employees of: A. The time to show up for work B. Information related to upcoming OSHA site audits C. Hazards the host employer has communicated tot he contract employer D. Any previous citations the host employer has been cited for by OSHA

C. Hazards the host employer has communicated tot he contract employer

When are overcurrent protective devices (OCPDs), such as fuses, circuit breakers, and protective relays allowed to be modified? A. When it is required by company policies and procedures B. When it is needed to get equipment started C. OCPDs cannot be modified at any time D. Any time

C. OCPDs cannot be modified at any time

The point of division of line and load is located at the _____ A. Customer's side of the service head B. Load side of the meter base C. Overcurrent devices in the service disconnecting means D. Service point

C. Overcurrent devices in the service disconnecting means

A ground rod is the only grounding electrode at a service. If the GEC becomes loose when connected to the rod, the branch-circuit breakers in the service panel will take _____ amount of time to open if a ground fault occurs in one of the branch circuits. A. A longer B. A Shorter C. The Same

C. The Same

A 200-Amp, 120/208-volt, 3 phase, 4-wire service consists of three 3/0 AWG ungrounded conductors and one grounded conductor. The smallest grounded conductor that can be installed for this service is ____ AWG. Most of the connected loads are 3 phase and won't use a neutral. A. 6 B. 1/0 C. 2 D. 4 E. 3/0

D. 4

An 1800-A, 120/208-volt, 3 phase, 4-wire service is to be installed underground using 6 paralleled Schedule 40 PVC conduits. The service equipment will be a fused switchboard. The minimum size of the aluminum main bonding jumper for this service is _____ AWG or kcmil. All conductors are THHN/THWN aluminum. A. 4/0 B. 500 C. 200 D. 400 E. 3/0

D. 400

Which of the following is NOT an example of a solidly grounded system? A. 120/207-volt, three-phase, four-wire B. 120/240-volt, three-phase, four-wire C. 120/240-volt, single-phase, three-wire D. 480-volt, three-phase, three-wire

D. 480-volt, three-phase, three-wire

An electrical safety program should include a section on: A. Responsibility B. Procedures C. Principles D. All of the above

D. All of the above

A 150/Amp, 120/208-volt, 3 phase, 4-wire service consists of three 1/0 AWG ungrounded conductors and one grounded conductor. The smallest grounded conductor that can be installed for this service is _____ AWG where the neutral load is expected to be 120 amps. A. 2 B. 6 C. 8 D. 4 E. 1

E. 1

Where each luminaire draws 1.2 ampls, if more than _____ luminaires are connected to Ckt. LA -4, the circuit breaker will be overloaded. 20-amp circuits LA-1, -4, and -11 with a neutral have been run as 4-wire, 12 AWG MC cable from a 120/208-volt, 3 phase, 4W panelboard to a junction box. Fluorescent luminaires have been installed in several offices in a business and connected to these circuits. The offices will be used continulously during the business day. A. 16 B. 17 C. 11 D. 12 E. 13

E. 13

A 208/120-volt, 3-ph, 4-wire panelbaord will be fed with one conduit. This service panel contains a 300-Amp main breaker. The conductors supplying the service will consist of three 350 kcmil ungrounded conductors (on for A phase, one for B phase, and one for C phase) plus a grounde conductor. The calculated neutral load is 170 amps. The smallest neutral that can be run is a ______ AWG A. 3 B. 2 C. 3/0 D. 4 E. 2/0

E. 2/0

True or False: It is not required to verify that a circuit or equipment has been deenergized as long as all of the other steps of the lockout/tagout procedure have been performed.

False

NEC sections 250.20, 250, 21 and 250.22 state when a system is required, permitted or not permitted to be grounded. Which of these transformer secondaries is NOT PERMITTED to be grounded? I. The output conductors from a fluorescent ballast supplied from a 120-V circuit II. 120 to 12-volt AC transformer for a low-voltage lighting system III. 480 to 120-VAC for a motor control circuit

I & II only

Which of the following are considered to be current-carrying conductors: I. Neutral Conductor II. Ungrounded Conductor III. Grounding Conductor

I and II only