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