WorksheetsCSP 3
Total questions: 15
Worksheet time: 8mins
A type of short-circuit defined as an unintentional connection between an ungrounded conductor of an electrical circuit and the normally non-current-carrying conductors, metallic enclosures, metallic raceways, metallic equipment, or earth defines a __________.
current limiter
ground conductor
ground fault
overload
A sustained overload current, if not interrupted in sufficient time, can result in _______ which may eventually cause severe damage or fires.
deterioration of insulation
extremely high current levels
overheating of conductors and components
Both a. and c.
Motor circuit protectors (MCPs) are devices that have a ______ only and are intended for only short-circuit and ground-fault protection for motor branch circuits.
electronic overload relay
instantaneous trip
short-time trip relay
terminal protection
Current limiting overcurrent protective devices can provide superior short circuit protection by reducing _______ on conductors and equipment.
heat from overloads
mechanical forces
thermal energy
both b. and c.
For non-motor loads the ______ rating of a fuse or circuit breaker normally should not exceed the current carrying capacity of the conductors or equipment to protect against overheating.
ampere
impedance
interrupting
voltage
The characteristic of the operating mechanism of a circuit breaker is ______ so as to prevent the breaker from being "teased" from OFF-to-ON or ON-to-OFF.
contact point reaction
mechanical response time
quick-make/quick-break
spring return function
Because circuit breakers are _____ devices, testing and maintenance must be performed to assure proper operation during overcurrent conditions.
mechanical
molded
passive
solid-state
Listed current-limiting fuses have _____ features that help prevent the installation of fuses that cannot provide a comparable minimum level of protection for critical rating and performance.
current-limiting
physical size rejection
time-current characteristic
voltage
Equipment intended to interrupt current at fault levels shall have a _____ rating not less than the nominal circuit voltage and the short-circuit current that is available at the line terminals of the equipment.
ampere
impedance
interrupting
voltage
The ground-fault protection system shall be performance tested when first installed on site and a written record of the test shall be available to the _____.
authority having jurisdiction
electrical contractor
insurance provider
owner
In order to do an arc-flash hazard assessment, typically it is necessary to first determine the available short-circuit current.
True
False
Various methods have been developed to actually calculate the available short-circuit current. All are based on _______.
Current limiting technology
Lenz's Law
Ohm's Law
Onderdonk Method
Zero sequence ground fault protection monitors current in?
all phase conductors and the equipment ground
all phase conductors and the neutral
the connection between neutral bus and ground bus
the equipment ground and neutral separately
Electronic sensing molded case circuit breakers can have several overcurrent protection adjust dials, as well as a dial for adjusting the GFPE setting incorporated into the electronic sensing unit.
True
False
Circuit breakers need to be ______ periodically.
exercised
reconditioned
removed
replaced
