Eaton Industrial Switchgear - General Information

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Rated uninterrupted current Iu
(cf. IEC/EN 60947-1; 4.3.2.4) Current that a switching device can carry in continuous
operation (for weeks, months or years).
Rating
(cf. IEC/EN 60947-1; 4.3.2.3) The power output of a motor at its rated operational
voltage.
Safe isolation
(cf. IEC 536) Isolation of circuits not carrying hazardous voltage, e.g. protective
extra-low voltage, from circuits in which hazardous voltage flows. Such isolation is
achieved by means of reinforced or double insulation, which reliably prevents volt-
age transfer from one circuit to another, for example between main and auxiliary
switchgear circuits or the primary and secondary sides of a safety transformer.
Safe isolation is required mainly for safety and functional extra-low voltage circuits.
Stopping in case of emergency
(EN ISO 13850) Function intended to prevent hazards or minimize existing risks for
people or of damage to machines or running processes, and which is triggered by
a single action by one person.
Tamper-proof
An Emergency-Stop switching device is regarded as tamper-proof if it cannot be
reset without tools or using specified procedures after tripping. The switching
device locks in its tripped position. Accidental or controlled manipulation (inching)
is not possible.
Utilization category
cf. IEC/EN 60947-1; 2.1.18/IEV 441-17-19) A combination of specified requirements
relating to the condition in which the switching device or fuse fulfills its purpose and
selected to represent a characteristic group of real-life applications. The specified
requirements may, for example, relate to the values of making and breaking
capacity and other characteristic values, data concerning associated circuits and
the applicable conditions of use and operational behavior.
(cf. IEC/EN 60947-2; 4.4) For circuit breakers, the utilization category denotes
whether the equipment is designed for selectivity using time delay (category B) or
not (category A).
Glossary of terms
Selected terms from the codes & standards of the USA
Accessible, Readily
NEC, Article 100) Readily accessible for operations, replacement or inspection with-
out having to breach or remove obstacles or having to use steps, etc.
Ampacity
(NEC, Article 100) Current in amperes that a conductor can continuously carry
under operational conditions without exceeding its permissible temperature.
Approved
(NFPA 79, Chapter 3) Acceptable for the Authority having Jurisdiction (AHJ).
Authority Having Jurisdiction
(NEC, Article 100) Organization, authority or person responsible for implementing
the stipulations of the Codes or Standards, or for approving equipment, materials,
installations or procedures.
Branch Circuit
Here the applicable standards deviate. NEC has highest priority, but the UL defini-
tion appears to be closer to reality. In any case, “branch circuit” denotes everything
that comes after the last overcurrent protective element.
(NEC, Article 100) Conductor in a circuit between the last overcurrent protection
element that protects the circuit and the apparatus.
(UL 508A, Part 1, Introduction, 2) Conductors and components after the last overcur-
rent protection element that protects a load.
Branch Circuit Overcurrent Device (BCOD)
(NEC, Article 100) Device suitable for protecting supply, feed and outgoer circuits or
apparatus across the whole range of overcurrents between the rated current and
its switching capacity. BCODs must have a breaking capacity appropriate for its
use, but no less than 5 kA.
Branch Circuit Protective Device
(UL 508A, Part 1, Introduction, 2) Fuses or circuit breakers that have been assessed
according to a safety standard with respect to the provision of overcurrent protec-
tion.
Circuit Breaker, CB
(NEC, Article 100) Device developed for non-automated opening and closing of a
circuit and which automatically opens a circuit at a fixed overcurrent without itself
being damaged if used correctly within its rated data.
Adjustable (if applicable for the circuit-breaker)
A qualifying termwhich indicates that the CB can be adjusted to variable trip values
of current, time or both within a particular range.
Instantaneous Trip (if applicable for the circuit-breaker)
A qualifying term which indicates that the CB is designed to trip without a delay.
Inverse Time (if applicable for the circuit-breaker)
A qualifying term which indicates that the CB is designed to trip with a delay such
that the delay decreases with increasing current.
Non adjustable (if applicable for the circuit-breaker)
A qualifying term which indicates that the CB’s tripping current or delay can not be
adjusted.
Setting (of circuit breakers)
The set current or time value, or both, at which an adjustable circuit-breaker is to
trip.
Combination Motor Controller
(UL 508A, Part 1, Introduction, 2) One or several devices that have been fitted to be
able to isolate the conductors of a circuit from their power supply (disconnecting
means), to protect the branch circuit (branch circuit protection), to switch the
motor (motor control) and to provide motor over-load protection for an individual
motor circuit.
Device
(NEC, Article 100) Assembly within an electrical system whose primary function is
to carry or control electrical energy.
Disconnecting means
(NEC, Article 100) Device or group of devices or other means through which the
conductors of a circuit can be isolated from their power supply.
Emergency Switching Off
(NFPA 79, Chapter 3) Emergency actuation that switches off the electrical power
supply to the installation or parts thereof.
Enclosed Industrial Control Panel
(UL 508A, Part 1, Introduction, 2) Factory-provided industrial control system
supplied within an enclosure or control panel.
Feeder
(NEC, Article 100) All conductors of a circuit between the incoming unit of the
source of a separate system or other power supply equipment and the last branch
circuit overcurrent device (unofficial definition, not from NEC: viewed from consum-
er to energy source).
Feeder Circuit
(UL 508A, Part 1, Introduction, 2) Conductor and switchgear on the supply side of a
branch circuit protective device (BCPD).
Field Installed Equipment
(UL 508A, Part 1, Introduction, 2) Devices that have been installed only after the
production of an indust-rial control panel and the application of an approval label.
Field Wiring
Conductors that are connected (on-site) by other persons to connect the industrial
control panel with power sources, remote control devices (local devices) and
consumers.
Fuse, Branch Circuit Type
(UL 508A, Part 1, Introduction, 2) Fuses of Classes CC, G, H, J, K, L, R and T. Can
provide branch circuit protection.