Loss of Voltage Protection
Starters using magnetic contactors usually derive the power supply for the contactor coil from the same source as the motor supply. An auxiliary contact from the contactor is used to maintain the contactor coil energized after the start command for the motor has been released. If a momentary loss of supply voltage occurs, the contactor will open and not close again until a new start command is given. this prevents restarting of the motor after a power failure. This connection also provides a small degree of protection against low power supply voltage and loss of a phase. However since contactor coils will hold the circuit closed with as little as 80% of normal voltage applied to the coil, this is not a primary means of protecting motors from low voltage operation.
Read more about this topic: Motor Controller
Famous quotes containing the words loss of, loss and/or protection:
“Faster, faster with no loss of ritual
Stiff minions without banners, a steady guard ...”
—Allen Tate (1899–1979)
“The poorest children in a community now find the beneficent kindergarten open to them from the age of two-and-a-half to six years. Too young heretofore to be eligible to any public school, they have acquired in their babyhood the vicious tendencies of their own depraved neighborhoods; and to their environment at that tender age had been due the loss of decency and self-respect that no after example of education has been able to restore to them.”
—Virginia Thrall Smith (1836–1903)
“The best protection parents can have against the nightmare of a daycare arrangement where someone might hurt their child is to choose a place that encourages parents to drop in at any time and that facilitates communication among parents using the program. If parents are free to drop in and if they exercise this right, it is not likely that adults in that place are behaving in ways that harm children.”
—Gwen Morgan (20th century)