CTE Series Automatic Transfer Switch

CTE Series Automatic Transfer Switch

The Cat® CTE Series transfer switches are configurable for applications requiring the dependability and ease of operation found in a full featured power contactor type transfer switch.

The CTE Series is equipped with the MX350 controller that is designed for the most demanding transfer or bypass switch applications providing enhanced connectivity for accurate and timely diagnostics and event recording.

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Technical Summary

Rating Range
Transfer Type
Open / Closed / 4 position switch
Switch Type
Contactor Based

Electrical Ratings

Control Power
40 to 4000 amperes, 2,3 or 4 poles
Enclosure Capability
NEMA 1, 3R, 4, 4X and 12
System Voltage Application
Available to 600 VAC, 50 or 60 Hz
Applicable Testing
  • Seismic tested and certified to IBC 2006 & OSHPD
  • CSA C22.2 No. 178 certified at 600 VAC
  • IEC 947-6-1 liste
  • Standard Equipment

    • The Cte Series Of Automatic Tranfser Switches
      • The Cat CTE Series power contactor type transfer switch makes use of a fully programmable/configurable microprocessor-based controller to allow the utmost in application flexibility. Further, the CTE Series is offered in a wide array of configurations enabling it to meet the needs of even the most highly critical load.
        Available configurations include:
        • 40-4000 Amps:
        • CTE Automatic Transfer Switches
        • CTED Delayed Transition Transfer Switches
        • CTEM Manual Transfer Switches

        • 100-4000 Amps:
        • CTECT Closed Transition Transfer Switches
        • CBTE Open Transition Bypass Switches
        • CBTED Delayed Transition Bypass Switches
        • CBTECT Closed Transition Bypass Switches
      • CTE Electrical Ratings
      • Drive Mechanism
        • All CTS switches employ the simple “over-center” principle to achieve a mechanically locked position in either normal or emergency and a high speed drive assures contact transfer in 100 ms or less. High contact pressure and positive mechanical lock allow for high withstand and closing ratings, exceeding UL requirements.
      • Neutral Switching
        • The CTE Series is available in true four pole designs for multi-source power systems that require switching the neutral. The neutral contact is on the same shaft as the associated main contacts. This design ensures positive operation, and prevents any possibility that the neutral contact will fail to open or close, as is possible when the neutral pole is an add-on accessory. The neutral contacts are identical to the main contacts, having the same current carrying and high withstand /closing ratings as the mains. They are designed to break last and make first to negate the possibility of transients while switching the neutral.
      • Safe Manual Operation
        • To operate the switch manually, a large easy-to- use handle is provided with the switch. When inserted, it fits securely, providing simple operation during installation and maintenance or in an emergency. Every CTE is provided with an operator inhibit switch to disconnect the electrical drive prior to maintenance. Fully enclosed wrap-around arc covers shield the main contacts and mechanical components, preventing operator exposure during manual operation
      • Cted Series:
        • The CTED offers a delayed transition on transfer switches 40A and above. This programmed center-off position allows for the full decay of rotating motors or transformer fields. It can also be used for load shedding of selected circuits or other applications which require a means to disconnect the load from either source. Many UPS system manufacturers recommend delayed transition switches to support sequencing of their systems.
      • Ctect Series:
        • Cat closed transition switches combine CTED operation during a source failure with a highly engineered control system that allows momentary paralleling (100 ms) of two acceptable sources, thereby limiting the impact of transfer on the load.
      • Bypass Isolation Switches Cbted & Cbtect
        • The bypass section is a Manual (MTS) switch that is provided with a quick break/quick make manual load transfer handle and control/interlock system consisting of both mechanical and electrical interlocks. The bypass MTS is equipped with Source 1 failure sensing and a time delay to start the engine automatically if the Automatic Transfer Switch (ATS) has been removed for service. The ATS and MTS modules are mounted in a compact enclosure and completely interconnected requiring only Source 1 (normal), Source 2 (emergency) and load cable connections. Once installed, no cables need to be removed to isolate the transfer switch module for maintenance or inspection. The ATS module has three positions:

        • 1. Automatic/Connected: The ATS is carrying the load, and the bypass MTS is in the open position. This is the normal operating position.

          2. Test: The bypass MTS is closed and feeding the load. The ATS has control power and may be operated for test purposes via the test switch. The load is not affected during testing.<.br>
          3. Isolate: The ATS is withdrawn from all power sources and ready for maintenance. The load is served by the bypass MTS.
        • The MTS is installed on a draw-out mechanism, with electrical and mechanical interlocks for secure removal after load bypass. The ATS control/logic panel is mounted on the enclosure door and connected by a wire harness and multi-pin disconnect plugs. The ATS and/or the control panel may be tested, isolated and removed for maintenance without load interruption.
        • The MX350 microcontroller is a modular control and monitoring system designed specifically for low voltage transfer switch applications.
          The MX350 provides the following key benefits:
          Flexible control and communication options to suit any low-voltage transfer switch application
          Small footprint
          Modular design, which reduces the number of spare components for maintenance and testing