Specification sheet OTEC Transfer Switch Open Transition 40 – 1200 amp OTEC transfer switches are designed for operation and switching of electrical loads between primary power and Standby generator sets. They are suitable for use in emergency, legally required, and optional Standby applications. The switches monitor both power sources, signal generator set startup, automatically transfer power, and return the load to the primary power source once a stable utility is available. The fully integrated controller is designed for practical functionality, with LED indicators and digital pushbuttons for ease of operator use. Microprocessor control - Easy-to-use, standard control. LEDs display transfer switch status; pushbuttons allow operator to activate control test, exercise timing and transfer mode. Programmed transition – Open transition timing can be adjusted to completely disconnect the load from both sources for a programmed time period, as recommended by NEMA MG-1 for transfer of inductive loads. Advanced transfer switch mechanism – Unique bidirectional linear actuator provides virtually frictionfree, constant force, straight-line transfer switch action during automatic operation. Manual operation - Manual operating handles, shielded termination, and over-center contact mechanisms allow effective manual operation under deenergized conditions. Positive interlocking - Mechanical and electrical interlocking prevent source-to-source connection through the power or control wiring. Main contacts - Heavy-duty silver alloy contacts and multileaf arc chutes are rated for motor loads or total system load transfer. They require no routine contact maintenance. Continuous load current not to exceed 100% of switch rating and Tungsten loads not to exceed 30% of switch rating. Easy service/access - Single-plug harness connection and compatible terminal markings simplify servicing. Access space is ample. Door-mounted controls are fieldprogrammable; no tool is required. Complete product line - Cummins offers a wide range of equipment, accessories and services to suit virtually any backup power application. Warranty and service - Products are backed by a comprehensive warranty and a worldwide network of distributors with factory-trained service technicians.

Transfer switch mechanism • Transfer switch mechanism is electrically operated and mechanically held in the Source 1 and Source 2 positions. The transfer switch incorporates electrical and mechanical interlocks to prevent inadvertent interconnection of the sources. • Independent break-before-make action is used for both 3-pole and 4pole/switched neutral switches. This design allows use of sync check operation when required, or control of the operating speed of the transfer switch for proper transfer of motor and rectifier-based loads (programmed transition feature). • True 4-pole switching allows...

Microprocessor control • Simple, easy-to-use control provides transfer switch information and operator controls • LED lamps for source availability and source connected indication, exercise mode, and test mode. LED status lamps also provided for control set-up and configuration. • Pushbutton controls for initiating test, overriding time delays and setting exercise time. • Field-configurable for in-phase open or programmed open transition. • Integral exerciser clock • Control is prototype-tested to withstand voltage surges per EN60947-6-1. • Gold-flashed generator start contacts Control functions...

UL withstand and closing ratings The transfer switches listed below must be protected by circuit breakers or fuses. Referenced drawings include detailed listings of specific breakers or fuse types that must be used with the respective transfer switches. Consult with your distributor/dealer to obtain the necessary drawings. Withstand and Closing Ratings (WCR) are stated in symmetrical RMS amperes.. MCCB protection Transfer switch ampere WCR @ volts max with specific manufacturers MCCBs Special circuit breaker protection Drawing reference With specific current limiting breakers (CLB) Drawing reference...

Enclosures The transfer switch and control are wall-mounted in a key-locking enclosure. Wire bend space complies with 2008 NEC. Dimensions - transfer switch in UL type 1 enclosure Depth Height Width Door closed Door open Outline drawing Dimensions - transfer switch in UL type 3R, 4, 4x, or 12 enclosure Door closed Door open Outline drawing Cabinet type

Transfer switch lug capacities All lugs 90˚C rated and accept copper or aluminum wire unless indicated otherwise. Transfer switch ampere #2 AWG to 600 MCM standard (feature N045) 1/0 AWG to 750 MCM optional (feature N066) Compression Lug Adapter optional (feature N032) Certification All switches are UL 1008 Listed with UL Type Rated cabinets and UL Listed CU-AL terminals. All switches comply with NEMA ICS 10. All switches are certified to CSA 282 Emergency Electrical Power Supply for Buildings, up to 600 VAC. All switches comply with IEEE 446 Recommended Practice for Emergency and Standby Power...

Submittal detail Amperage ratings • • • • • • • • • • • • Voltage ratings • • • • • • • • • • Pole configuration • A028 Poles - 3 (solid neutral) • A029 Poles - 4 (switched neutral) Control voltage • M033 12V, Genset starting voltage • M034 24V, Genset starting voltage Control options • J030 External exercise clock • M032 Elevator signal relay Auxiliary relays Relays are UL Listed and factory installed. All relays provide (2) normally closed isolated contacts rated 10A @ 600 VAC. Relay terminals accept (1) 18 gauge to (2) 12 gauge wires per terminal. • L101 24 VDC coil - installed, not wired...