Electrical Level 3 Module 5 Over Current Protection n n n n n n n
Questions with Correct Answers | Rated A+ n n n n n n n
110 overcurrent protection
n n
Types of fault current include the following: - CORRECT ANSWER -Overloads, short circuits, ground
n n n n n n n n n n n n n
faults, arc faults
n n n
110 overload conditions
n n
Continuous overloads can result from - CORRECT ANSWER -defective motors (motors with
n n n n n n n n n n
worn bearings) overload equipment, or too many loads on one circuit
n n n n n n n n n n n
120 short circuit conditions
n n n
NEC section 110.9 states that equipment intended to interrupt current at fault levels (fuses and
n n n n n n n n n n n n n n
circuit breakers) shall have an interrupting rating at nominal circuit voltage
n n to the current
n n n n n n n n n n n
that is available at the line terminals of the equipment - CORRECT ANSWER -At least equal
n n n n n n n n n n n n n n n n
130 Ground Faults
n n
Unintentional conducting connection between any of the conductors of an electrical system and the
n n n n n n n n n n n n n
conducting material that encloses the conductors or any conducting material, such as a
n n n n n n n n n n n n n
metal enclosure, that is grounded or may become grounded - CORRECT ANSWER -Ground fault
n n n n n n n n n n n n n
140 Arc faults
n n
480V circuits, the arc current may be as low as
n of the available bolted fault current and
n n n n n n n n n n n n n n
seldom exceeds
n - CORRECT ANSWER -Low: 38% seldom exceeds 60%
n n n n n n n n
211 voltage rating
n n
The voltage rating of a fuse must be
n n n n n n n - CORRECT ANSWER -At least equal or greater than the
n n n n n n n n n
circuit voltage
n n
Questions with Correct Answers | Rated A+ n n n n n n n
110 overcurrent protection
n n
Types of fault current include the following: - CORRECT ANSWER -Overloads, short circuits, ground
n n n n n n n n n n n n n
faults, arc faults
n n n
110 overload conditions
n n
Continuous overloads can result from - CORRECT ANSWER -defective motors (motors with
n n n n n n n n n n
worn bearings) overload equipment, or too many loads on one circuit
n n n n n n n n n n n
120 short circuit conditions
n n n
NEC section 110.9 states that equipment intended to interrupt current at fault levels (fuses and
n n n n n n n n n n n n n n
circuit breakers) shall have an interrupting rating at nominal circuit voltage
n n to the current
n n n n n n n n n n n
that is available at the line terminals of the equipment - CORRECT ANSWER -At least equal
n n n n n n n n n n n n n n n n
130 Ground Faults
n n
Unintentional conducting connection between any of the conductors of an electrical system and the
n n n n n n n n n n n n n
conducting material that encloses the conductors or any conducting material, such as a
n n n n n n n n n n n n n
metal enclosure, that is grounded or may become grounded - CORRECT ANSWER -Ground fault
n n n n n n n n n n n n n
140 Arc faults
n n
480V circuits, the arc current may be as low as
n of the available bolted fault current and
n n n n n n n n n n n n n n
seldom exceeds
n - CORRECT ANSWER -Low: 38% seldom exceeds 60%
n n n n n n n n
211 voltage rating
n n
The voltage rating of a fuse must be
n n n n n n n - CORRECT ANSWER -At least equal or greater than the
n n n n n n n n n
circuit voltage
n n
