Terms beginning R - W

The SPDC Glossary is a compilation of the terms extracted from SPDC 2011 active Standards, Guides and Recommended Practices. The last line of each term definition references the document number the term came from. There are 135 terms with multiple entries as the term has occurred in several documents. There are over 400 unique terms in the Glossary. The Glossary terms are alphabetically arranged, with a page for each letter. If the Glossary is directly accessed, a randomly selected term and definition is given at the top of the page. Once a particular letter page is selected, the random term disappears.

Clicking on a term on this page will take you to that Glossary page for that term definition. The following terms are defined in the Glossary:

R – radio-influence voltage (RIV), rated average power dissipation, rated dc voltage (Varistor), rated forward surge current, rated peak impulse current, rated peak impulse power, rated peak single pulse transient current (Varistor), rated peak single-pulse transient current, rated recurrent peak voltage (Varistor), rated RMS Voltage (Varistor), rated single pulse transient energy (Varistor), rated single-pulse transient energy, rated standby power dissipation, rated standoff (working) voltage, rated test voltage (rotating electric machinery), rated transient average power dissipation (Varistor), rated voltage, rated voltage (rotating electric machinery), rating, recovery voltage, reference current, reference voltage, reignition, remote earth (potential), remote surge (rotating electric machinery), repetitive peak forward current, repetitive peak off-state current, repetitive peak off-state voltage, repetitive peak on-state current, repetitive peak reverse current, repetitive peak reverse voltage, repetitive rating, repetitive surge and follow-current withstand, resistance (Varistor), resonant grounded neutral system, response time (Varistor), restrike, reverse direction, reverse-blocking diode thyristor surge protection device (SPD), reverse-blocking quadrant, reverse-blocking triode thyristor surge protection device (SPD), ring wave, riser pole type arrester, routine tests

S – secondary arrester, self-restoring insulation, series gap, service entrance equipment, service equipment, service voltage, severe lightning current, shield wire (electromagnetic fields), shielding angle, short circuit, short-circuit current (SCC), short-circuit current rating (SCCR) of a surge-protective device, shunt gap, sparkover, standard chopped wave impulse voltage shape, standard lightning impulse, standard lightning impulse voltage shape, standard power-frequency short-duration voltage shape, standard switching impulse voltage shape, standard switching impulses, stand-by current, stand-off (nonconducting) region, statistical basic lightning impulse insulation level (BIL), statistical basic switching impulse insulation level (BSL), statistical BIL, statistical BSL, statistical withstand voltage, steep-front surge (rotating electric machinery), surge, surge arrester, surge arrester, surge let-through, surge protective device (SPD), surge protector, surge remnant, surge response voltage, surge-protective device (SPD), swell, switching current, switching impulse protective level of a surge-protective device, switching overvoltage, switching point, switching quadrant, switching resistance, switching surge, switching voltage, system (circuit) voltage, system voltage

T – temperature coefficient of breakdown voltage, temperature derating, temporary overvoltage, temporary overvoltage (TOV), terminals, thermal resistance, thyristor, time-to-crest value, time-to-half value, time-to-impulse sparkover, tracking, transfer time, transient overvoltage, transient thermal impedance, transient voltage surge suppressor (TVSS), transition current, transition time, transmission line arrester, traveling wave, turn insulation (rotating electric machinery), two-port SPD, Type 1 SPD, Type 2 SPD, Type 3 SPD, Type 4 SPD

U – ultimate mechanical strength-static (UMS-static), ungrounded (isolated) system, unidirectional thyristor surge protection device (SPD), unit operation, upset, utilization voltage

V – valve arrester, valve element, variation of holding current with temperature, Varistor voltage, vent, very fast front voltage shape, very fast front, short-duration overvoltage, virtual current chopping (rotating electric machinery), virtual duration of wave front (of an impulse), virtual junction temperature, virtual zero point (of an impulse), voltage clamping ratio (Varistor), voltage overshoot (Varistor), voltage protection level, voltage rating, voltage shape

W – wave, wave front (of a surge or impulse), wave shape (of an impulse test wave), wave shape designation (of an impulse), wave tail (of an impulse), waveform, withstand voltage