DB HIGH CURRENT SWITCHES
High Current Switches for non-load switching for bus disconnecting or transfer erectifier disconnect polarity reversing. Ideal for ecelctrolitic cell (cell shortning).




SOME OF OUR SWITCH CAPABILITIES
Bolted Pressure COntact Switches
Grounding Switches
Hook Stick Switches
Knife Switches
Special Design Switches
Transfer Switches
Test Swicthes
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MANUAL OPERATOR
The manual operator consists of a cast indicating plate with stops, indicating OPEN and CLOSED, and a cast hub that has a socket for the wood handle. The hub has a pull-to-turn latch at both positions. The four methods of furnishing the manual operator are shown below.

MANUAL OPERATOR
NOTE: The cover, indicating plate and handle hub are at bus potential when switch is closed. The handle length varies to provide approximately 40 pounds operating effort.
Some applications of DB switches require their use in the normally open position, others in the normally closed position. When pneumatically operated, the air cylinders are continually subjected to air pressure to avoid drifting of the switch. Air cylinders are mounted as shown in the two configurations below; i.e., with the piston rods retracted into the cylinders for the position, pen or closed, that is normal for the switch. This is done to minimize dirt collection and corrosion of the piston rod.

PNEUMATIC OPERATOR
Air cylinders are sized to provide a safety factor with the recommended or specified pressure rating. Dry lubricated instrument air is recommended.
For typical dc applications the switch cover-plate, air cylinder mounting, air cylinder and linkage are at bus potential when the switch is closed. Flexible insulated air lines are required. If solenoid operated valves are used, the conduit must be insulated and flexible.
Ampere Ratings of the switches listed are based on one pair of moving contacts per 1000 amperes. The temperature rise of the switch depends on the bus temperature since they will equalize and the switch cannot run cooler than the bus. On the intermittent duty it may be possible to use a smaller rated switch depending on the open and close intervals, bus temperature and ambient conditions.
Auxiliariy Switch: There are two basic uses for auxiliary switches depending upon the application. They are as follows:
General indicationIndicates approximate position of main switch contacts, within 30º of travel: e.g., when the auxiliary contacts are closed with the main contacts closed, the auxiliary contacts will open within 30º of the opening stroke of the main switch. When the auxiliary contacts are closed with the main contacts open, the auxiliary contacts will open within 30º of the closing stroke. Typical use is pilot light indication.
Specific indicationIndicates exact position of main switch contacts, open or closed, within 10º of travel: e.g., when the auxiliary contacts are closed with the main contacts closed, the auxiliary contacts will open before the main switch contacts separate on the opening stroke. When the auxiliary contacts are closed with the main contacts open, the auxiliary contacts will open as the main switch contacts just start to move toward the closed position. Besides the fully opened and closed positions, auxiliary switches can be located at various points along the arc of travel of the main movable contacts. Typical uses are interlocking or sequencing of auxiliary equipment such as pumps or fans; Not to be used to initiate the electrical control circuit of the load switching device; e.g., electrically operated circuit breaker or circuit interrupter.
AUXILIARTY SWITCH ARCHING CONTACTS

Load Switching Arc Contacts as supplied on the 6 volt DC switches consist of one stationary and two moving arc contacts all having tungsten alloy are tips. They provide initial contact before the main contacts on closing and break contact after the main contacts on opening. They are of rugged construction, factory adjusted and easily replaced.
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