|
SPDC Terms M-N
MAIN DISCHARGE CURRENT WAVE
The relatively long portion of the ESD current wave that follows the initial current pulse, or that occurs by itself when the initial current pulse doesn't exist. It may be unidirectional or oscillatory; its initial slope may be fast or slow.
[C62.47–1992]
MAINS
The ac power source available at the point of use in a facility. It consists of the set of electrical conductors (referred to by terms including "service entrance", "feeder", or "branch circuit") for delivering power to connected loads at the utilization voltage level.
[C62.41–1991]
MAIN TERMINALS
The two terminals through which the principal current flows.
NOTE:The main terminals may be named by application usage. In telecommunications, terminals may be named after the line connections of R(ing), T(ip), and G(round) or A, B, and C(ommon).
[C62.37–1996 & STD. 100-2000]
MAIN TERMINAL 1
The main terminal that is named 1 by the device manufacturer.
[C62.37–1996]
MAIN TERMINAL 2
The main terminal that is named 2 by the device manufacturer.
[C62.37–1996]
MAXIMUM (HIGHEST) SYSTEM VOLTAGE
The highest voltage at which a system is operated.
NOTE: This is generally considered to be the maximum system voltage as prescribed in ANSI C84.1–1989
[C62.1–1989 & C62.11–1987 & C62.22–1991]
The highest rms phase-to-phase voltage that occurs on the system under normal operating conditions, and the highest rms phase-to-phase voltage for which equipment and other system components are designed for satisfactory continuous operation without derating of any kind. (This voltage excludes voltage transients and temporary overvoltages caused by abnormal system conditions such as faults, load rejection, and so forth.)
[C62.2–1987]
MAXIMUM CONTINUOUS OPERATING VOLTAGE (MCOV)
The maximum designated root-mean-square (rms) value of power frequency voltage that may be applied continuously between the terminals of the arrester.
[C62.11–1987 & C62.22–1991]
MAXIMUM JUNCTION TEMPERATURE
(TJM)
The maximum value of permissible junction temperature, due to self heating, which a Thyristor SPD can withstand without degradation.
[C62.37–1996]
MAXIMUM RATING; ABSOLUTE MAXIMUM RATING
A rating that establishes either a limiting capability or a limiting condition beyond which damage to the device may occur.
NOTE - A limiting condition may be either a maximum or a minimum.
[C62.37–1996]
MEANS OF GROUNDING
The generic agent by which various degrees of grounding are achieved; for example, inductance grounding, resistance grounding, and resonant grounding.
[C62.92.1–1987]
MECHANICAL LIMIT
The rated maximum instantaneous value of current, in amperes, that the device will withstand without mechanical failure.
[STD 32–1990]
METAL-OXIDE SURGE ARRESTER (MOSA)
A surge arrester utilizing valve elements fabricated from nonlinear resistance metal-oxide materials.
[C62.11–1987]
METHODS (OR TYPES) OF GROUNDING
The equipment, procedure, or scheme used for attaining the particular means.
[C62.92.1–1987]
MINIMUM IMPULSE FLASHOVER VOLTAGE
The crest value of the lowest voltage impulse at a given wave shape and polarity that causes flashover.
[STD 32–1990]
MULTIPLE ESD EVENT
An ESD event in which more than one discharge occurs. The time interval between successive discharges may be several microseconds to several tens of milliseconds. Related terms include multiple ESD, multiple discharge and multiple normalized peak ESD current. Ratio of peak current to charge voltage (e.g. 5 A/kV)
[C62.47–1992]
NEGATIVE DIFFERENTIAL-RESISTANCE (REGION)
The region of the principal voltage-current characteristic in the switching quadrant where the differential resistance is negative and the thyristor is switching between the breakdown and on-state regions.
[C62.37–1996]
NEGATIVE-BREAKDOWN RESISTANCE THYRISTOR SPD
A thyristor SPD, whose static breakdown characteristic has a net negative-resistance slope prior to switching.
[C62.37–1996]
NEUTRAL GROUND CAPACITOR
A neutral grounding device, the principal element of which is capacitance.
[STD 32–1990]
NEUTRAL GROUNDING DEVICE
A grounding device used to connect the neutral point of a system of electric conductors to earth.
NOTE: The device may consist of a resistance, inductance, or capacitance element, or a combination of them.
[STD 32–1990]
NEUTRAL GROUNDING IMPEDOR
A neutral grounding device comprising an assembly of at least two of the elements, resistance, inductance, or capacitance.
[STD 32–1990]
NEUTRAL GROUNDING REACTOR
A neutral grounding device, the principal element of which is inductive reactance.
[STD 32–1990]
NEUTRAL GROUNDING RESISTOR
A neutral grounding device, the principal element of which is resistance.
[STD 32–1990]
NEUTRAL GROUNDING WAVE TRAP
A neutral grounding device comprising a combination of inductance and capacitance designed to offer a very high impedance to a specified frequency or frequencies.
NOTE: The inductances used in neutral grounding wave traps should meet the same requirements as neutral grounding reactors.
[STD 32–1990]
N-GATE THYRISTOR
A three-terminal thyristor in which the gate terminal is connected to the n-region adjacent to the region to which the anode is connected and that is normally switched to the on state by applying a negative signal between the gate and anode terminals.
[C62.37–1996]
NOMINAL RATE OF RISE (OF AN IMPULSE WAVE FRONT)
(For a wave front,) The slope of the line that determines the virtual zero. It is usually expressed in volts or amperes per microsecond.
[C62.1–1989 & C62.2–1987 & C62.11–1987 & (C62.22–1991)]
NOMINAL SYSTEM VOLTAGE
A nominal value assigned to designate a system of a given voltage class.
NOTE: See ANSI C84.1–1989
[C62.1–1989 & C62.11–1987]
The system voltage by which the system may be designated, and to which certain operating characteristics of the system are related. (The nominal voltage of a system is near the voltage level at which the system normally operates and provides a per-unit base voltage for system study purposes. To allow for operating contingencies, systems generally operate at voltage levels about 5 to 10 % below the maximum system voltage for which the system components are designed.)
[C62.2–1987 & C62.22–1991]
NOMINAL VARISTOR VOLTAGE
Voltage across the varistor measured at a specified pulsed dc current, IN(dc), of specific duration. IN(dc) is specified by the varistor manufacturer.
[C62.33–1989]
NONLINEAR EXPONENT
A measure of varistor nonlinearity between two given operating currents,
I1 and I2, as described by I = k Va where k is a device constant, Il < I < I2,
and a12 = log(I2/I1)/log(V2/V1)
[C62.33–1989]
NON-REPETITIVE CURRENT RATING
A maximum rating that may be applied to the device for a minimum of 100 times over the life of the device without failure. During the rated condition, the device is permitted to exceed its maximum rated junction temperature for short periods of time. The device is not required to block voltage or retain any gate control during or immediately following this rated condition until the device returned to the original thermal equilibrium conditions. This rated condition may be repeated after the device has returned to the original thermal equilibrium conditions.
[C62.37–1996]
NON-REPETITIVE PEAK FORWARD CURRENT
(IFSM)
Rated maximum (peak) value of ac power frequency forward surge current of specified waveshape and frequency which may be applied for a specified time or number of ac cycles.
[C62.37–1996]
NON-REPETITIVE PEAK ON-STATE CURRENT
(ITSM)
Rated maximum (peak) value of ac power frequency on-state surge current of specified waveshape and frequency which maybe applied for a specified time or number of ac cycles.
[C62.37–1996]
NON-REPETITIVE PEAK PULSE CURRENT
(IPPS)
Rated maximum value of peak impulse pulse current of specified amplitude and waveshape that may be applied.
[C62.37–1996]
NORMALIZED RISING SLOPE
Ratio of the initial slope to charge voltage (e.g. 3.75 A/ns/kV).
[C62.47–1992]
|
