IES (INDUSTRIAL ELECTRICAL
SERVICE OKLAHOMA) UNIT 2
CIRCUIT PROTECTION CORRECT
100%
Arc fault - ANSWERan unintentional electrical discharge characterized by low and
erratic current that may ignite combustible materials.
Arc-Fault Circuit-Interrupter - ANSWERa device intended to provide protection from the
effects of arc faults by recognizing characteristics unique to arcing and by functioning to
de-energize the circuit when an arc fault is detected.
Circuit Breaker - ANSWERA device designed to open and close a circuit by
nonautomatic means and to open the circuit automatically on a predetermined over-
current without damage to itself when properly applied within its rating.
Overcurrent - ANSWERAny current in excess of the rated current of equipment or the
ampacity of a conductor. It may result from overload, short circuit, or ground fault.
Overload - ANSWEROperation of equipment in excess of normal, full load rating, or of a
conductor in excess of rated ampacity which, when it persists for a sufficient length of
time, would cause damage or dangerous overheating. A fault, such as a short circuit or
ground fault, is not an overload.
Short Circuit - ANSWERA circuit that connects the energized lines directly together or
an energized line directly to ground, resulting in immediate maximum current flow.
Dual Element Fuse - ANSWERA fuse with a fuse link, a coil spring, and a low-melting-
point alloy that is designed to open on overload or short circuit.
Fuse - ANSWERAn over-current protective device with a circuit opening fusible part that
is heated and severed by the passage of over-current through it.
Ground-fault Circuit-interrupter (GFCI) - ANSWERA device intended to protect
personnel by deenergizing a circuit or portion thereof within an established time when a
current to ground exceeds 6 milli-amps. This is a very small fraction of the current
required to operate the supply circuit overcurrent device
Link - ANSWERThe part in the fuse that is used to melt and break the circuit upon short
circuit or over-current, usually made of silver.
SERVICE OKLAHOMA) UNIT 2
CIRCUIT PROTECTION CORRECT
100%
Arc fault - ANSWERan unintentional electrical discharge characterized by low and
erratic current that may ignite combustible materials.
Arc-Fault Circuit-Interrupter - ANSWERa device intended to provide protection from the
effects of arc faults by recognizing characteristics unique to arcing and by functioning to
de-energize the circuit when an arc fault is detected.
Circuit Breaker - ANSWERA device designed to open and close a circuit by
nonautomatic means and to open the circuit automatically on a predetermined over-
current without damage to itself when properly applied within its rating.
Overcurrent - ANSWERAny current in excess of the rated current of equipment or the
ampacity of a conductor. It may result from overload, short circuit, or ground fault.
Overload - ANSWEROperation of equipment in excess of normal, full load rating, or of a
conductor in excess of rated ampacity which, when it persists for a sufficient length of
time, would cause damage or dangerous overheating. A fault, such as a short circuit or
ground fault, is not an overload.
Short Circuit - ANSWERA circuit that connects the energized lines directly together or
an energized line directly to ground, resulting in immediate maximum current flow.
Dual Element Fuse - ANSWERA fuse with a fuse link, a coil spring, and a low-melting-
point alloy that is designed to open on overload or short circuit.
Fuse - ANSWERAn over-current protective device with a circuit opening fusible part that
is heated and severed by the passage of over-current through it.
Ground-fault Circuit-interrupter (GFCI) - ANSWERA device intended to protect
personnel by deenergizing a circuit or portion thereof within an established time when a
current to ground exceeds 6 milli-amps. This is a very small fraction of the current
required to operate the supply circuit overcurrent device
Link - ANSWERThe part in the fuse that is used to melt and break the circuit upon short
circuit or over-current, usually made of silver.
