Commercial Wiring Final Exam
Questions and Correct Answers
Too many devices on one circuit could cause a type of overcurrent known as ______________
answer - overload
A(n) ______________ occurs when there is a low-resistance path between conductors answer -
short circuit
A(n) ___________ is a short between a hot conductor and a grounding path answer - ground
fault
Circuit breakers can be operated _______________ answer -
electrically,manually,pneumatically. All of the above
An inverse-time circuit breaker allows as much as __________ times the overload current
before opening the circuit answer - 10
The NEC _____________ rule allows a feeder conductor of smaller ampacity to be tapped
without overcurrent protection at the tap. answer - 10-foot tap
All electrical circuits are required to protect against overcurrent. answer - True
Typically, branch circuit overcurrent devices are located in the power panel. answer - True
Circuit breakers have to be replaced after they detect an overcurrent answer - False
, The ampere rating of an overcurrent protection device is usually the same as the current-
carrying capacity of the circuit conductor answer - True
The fusible link can be replaced in renewable fuses answer - True
Cartridge fuses are used in circuits over 120 volts or over 30 amps answer - True
Single-element fuses are designed for circuits with transient surge currents. answer - False
Type S fuses must be used on all new installations and for replacement installations. answer -
True
The voltage rating of a fuse should never be lower than the circuit rating answer - True
Circuit breakers are NOT permitted to serve as a disconnecting switch answer - False
The conductors extending from the utility pole to the facilities equipment are called the
___________ answer - service
When run overhead, the service is called the __________ answer - service drop
Conductors in a service drop are supported by a _________________ answer - service mast
The minimum vertical clearance of service-drop conductors ranges from ________________
answer - 10' to 24.5'
Questions and Correct Answers
Too many devices on one circuit could cause a type of overcurrent known as ______________
answer - overload
A(n) ______________ occurs when there is a low-resistance path between conductors answer -
short circuit
A(n) ___________ is a short between a hot conductor and a grounding path answer - ground
fault
Circuit breakers can be operated _______________ answer -
electrically,manually,pneumatically. All of the above
An inverse-time circuit breaker allows as much as __________ times the overload current
before opening the circuit answer - 10
The NEC _____________ rule allows a feeder conductor of smaller ampacity to be tapped
without overcurrent protection at the tap. answer - 10-foot tap
All electrical circuits are required to protect against overcurrent. answer - True
Typically, branch circuit overcurrent devices are located in the power panel. answer - True
Circuit breakers have to be replaced after they detect an overcurrent answer - False
, The ampere rating of an overcurrent protection device is usually the same as the current-
carrying capacity of the circuit conductor answer - True
The fusible link can be replaced in renewable fuses answer - True
Cartridge fuses are used in circuits over 120 volts or over 30 amps answer - True
Single-element fuses are designed for circuits with transient surge currents. answer - False
Type S fuses must be used on all new installations and for replacement installations. answer -
True
The voltage rating of a fuse should never be lower than the circuit rating answer - True
Circuit breakers are NOT permitted to serve as a disconnecting switch answer - False
The conductors extending from the utility pole to the facilities equipment are called the
___________ answer - service
When run overhead, the service is called the __________ answer - service drop
Conductors in a service drop are supported by a _________________ answer - service mast
The minimum vertical clearance of service-drop conductors ranges from ________________
answer - 10' to 24.5'
