Undervoltage

Thus, the protection will not prevent the closing of the contactor or the breaker when the supply voltage is 85% or more, nor will it trip the motor until the voltage falls to a low of 65% of the rated voltage. In both cases, therefore, separate undervoltage protection will be essential. This problem, however, is a theoretical one, as an industrial power system would seldom fluetuate so widely. 

Such a relay is connected on the supply side as shown in Figure 12.23(a). The arrangement is such that unless the relay closes, the motor switching circuit will not energize and ihe motor will not start. The contact closes only when the supply voltage is normal and the phase sequence positive. Even for undervoltage conditions, ihe torque developed by the relay may not be adequate to close the circuit. Such relays are. therefore, effective against... 

The electrical interlocking should preferably be provided through shunt trip releases. It must have a separate a.c. or d.c. source of control supply, such that the operation of the scheme is independent of the main source of supply. For the same reason, interlocking through undervoltage (U/V) releases is not recommended as its... 

As an energized capacitor retains its charge, even after a disconnection and causes a voltage transient on a reswitching, it is recommended that its circuit be closed only through a contactor or a breaker, with an undervoltage release. So that in the event of a power failure, the circuit will interrupt automatically... 

Additional funetions are added to the basie switehing power supply so that the supply s operation better eomplements the funetion of the overall produet. The overviewed funetions are those routinely found in some switehing power supplies, but eertainly are not all of the possible funetions. These funetions may inelude synehronization, undervoltage alerts, input undervoltage inhibit, and partial supply shut-down. 

Untersetzscherbe, /. plate or saucer set under something, (for crucibles) crucible stand. Unterspannung, /. (Elec.) undervoltage, low tension. 

This negative overvoltage in the anodic hole transfer reaction may better be called the undervoltage or the inverse overvoltage (the negative overvoltage in the anodic reaction) rather than the usual overvoltage which is positive in the... 

Undervoltage problems don t cause damage to hardware, usually. More often, they cause the computer to shut down completely (or at the very least, to reboot), thus losing any unsaved data in memory. There are three major types of undervoltage problems sags, brownouts, and blackouts. 

Which power device would be best to attach to your computer if you were having undervoltage power problems ... 

B. The better choice for undervoltage problems would be the UPS. The computer equipment is always running off the battery. While the line voltage is normal the battery gets charged. When power fluctuates, only the charging circuit is affected. 

In a recent STM study by Carnal et al. [3], these assumptions have been confirmed by the observation that a hexagoiuilly close-packed adlayer with slightly compressed Tl-Tl interatomic distances is formed at more anodic potentials, followed by the formation of a second hep adlayer with slightly disordered domains at small undervoltages. The progress of the formation of the first adsorbate layer was studied in that work by more conventional STM imaging techniques and was restricted to investigations at file stepped terrace domains. As shown in detail in [3], the formation of the first adsorbate layer at the stepped terrace domains follows the same scheme as shown in Fig. 2 for the system Pb/Ag(l 11), i.e. 

Undervoltage tripping facilities for mechanically latched contactors. 

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