Application and Ratings
The Chance unitized D7 is a distribution-level, gang-operated, side-break switch for 15 through 38 kV applications. It is pre-assembled, adjusted, and mounted on a common support at the factory for three-phase service. D7 switches meet a continuous-current rating of 600 amperes, a momentary rating of 40,000 amperes, a three-second short time current rating of 25,000 amperes, and applicable NEMA and ANSI standards. It is available in 15 kV (110 kV LIW*), 27 kV (150 kV LIW*), 34.5kV (150kV LIW*) or 38 kV (200 kV LIW*). The D7 is a 600-ampere loadbreak switch with the Duogap® expulsion interrupters. With the Duogap, the D7 is capable of switching load currents up to 600 amperes, with full recovery voltage across the switch, and interrupting transformer magnetizing and line-charging currents. This switch may be used for disconnecting, line sectionalizing, circuit breaker bypassing, and isolating.
*Lightning Impulse Withstand (BIL)Convenient Installation
Field installation time of this pre-assembled switch is greatly reduced below what is usually required to install separate gang-operated distribution level switches. The three-phase unit is conveniently raised in one piece to its mounting position, secured to the pole, control sections attached, and field adjustment made. Proper synchronization and phase spacing have been made at the factory. Unitized switches are installed in 2 to 4 hours, compared to non-unitized switches that take 6 to 8 hours.
HUBBELL / CHANCE COMPANY – CENTRALIA, MISSOURI
