Welcome to the ASCO Website

Welcome to our website.

Choose another country or region

ASCO Three-source system

For Customized Mission Critical Applications

Control logic for selecting between the alternative power sources. Normal, emergency, and/or load circuit breakers Protective relaying (as required) Optional instrument meters for normal, emergency, or load for local monitoring.

ASCO Three-source system
  • Features

    • Designs are based on NEMA and UL 891 standards.
    • Optional engine start control logic and/or load control logic.
    • Available up through 4000 amperes using ASCO 7000 series automatic transfer switches. 
    • 7ATS, 7ATB, 7ACTS and 7ACTB.


    • Banking, Financial and Insurance
    • Broadcast and Entertainment
    • EducationFire/Alarm/Security
    • Government
    • Healthcare
    • Manufacturing
    • Power Generation
    • Telecom
    • Transportation

Need a technical document?

Search our download center to find drawings, manuals and data sheets for your product.

Need support?

Contact our support team for technical help and information.

Ready to order?

Find your local ASCO sales representative.