Positive Mechanical and Electrical Interlocking | B
A rugged mechanical interlock between the normal and emergency contacts which positively prevents both sources from being closed simultaneously.
Quick-Break, Quick-Make, High-Speed, Preloaded Transfer | C
During transfer, the contact mechanism is securely locked in position until the overcenter position is reached. The preloaded springs then instantaneously open the closed contacts (quick-break) and instantaneously close the open contacts (quick-make) with a momentary break in between. The quick-break feature provides for full arc interruption, under maximum voltage and amperage, in less than one-half cycle. This considerably reduces contact erosion and increases the useful life of the switch.
Rapid and Reliable Arc Quenching | D
The current interrupting chamber of the Russelectric® transfer switch consists of parallel steel plates partially surrounding the contacts and enclosed by an insulator. When the contacts open, the induced magnetic field draws the arc into the plates where it is split into a series of smaller arcs and extinguished. The plates also conduct heat away from the arc. (Photo shown with insulating barriers removed.)
High-Speed Manual Operator | E
The manual operator (external standard, internal optional) transfers the switch with the same instantaneous contact opening and contact closing speed as the electrical operator. The switching mechanism, whether electrically or manually actuated, uses the preloaded transfer principle that precludes the possibility of a flashover or heavy arcing. When performing a manual transfer, operators should adhere to NFPA-70E requirements.
Safe External Manual Operator
External manual operator permits manual operation of the switch with the door fully closed for added safety.
Front Connected Control Components and Wiring | F
Transfer switch bases and control components and wiring can be replaced without removing the transfer switch from its enclosure.
Tracing of the electrical circuitry is simplified by the neatly arranged, front-connected, flame retardant, 600-volt SIS switchboard wiring. Heavy-duty control components and contacts are provided to handle switching requirements.
All wiring connections are made using crimped terminals and sleeve-type marking labels.
Vertical-Type “VS” Switchboard Construction | G
Transfer switch bases and control panels are available in narrow widths for installation in switchboard cubicles with either front or rear terminals and/or bus tabs. Narrow widths are available to fit motor control center requirements (19″ for capacities to 800 amperes 3-pole). Special arrangements are also available.
Click here to download a Technical Brief on the use of Dual-Operator Automatic Transfer Switches — Eliminating Power Transients When Switching Large Inductive Loads