Power Transfer Switches

ASCO SERIES 300 Group G Power Transfer Switch

Automatically transfer critical loads in the event of a power outage with the ASCO SERIES 300. Rugged construction and proven performance assure the user of many years of reliability.​​

Best Suited For
  • Banking, Financial and Insurance
  • Broadcast and Entertainment
  • Construction and Engineering
  • Data Center/Colocation/Hosting
  • Education
  • Fire/Alarm/Security
  • Government
  • Healthcare
  • Manufacturing
  • Power Generation
  • Power/Gas Transmission and Distribution
  • Retail and Wholesale
  • Telecom
  • Transportation
Limited Guardian Warranty


*To see model-specific downloads, you will need to go to the model-specific product page by selecting the model name in the specifications chart above.


The SERIES 300 is listed to UL 1008 standard for total system loads
and CSA standard C22.2 for automatic transfer switches.
Meets NFPA 110 for Emergency and Standby Power Systems.
Easy-to-navigate 128x64 graphical LCD display with keypad provides LED indicators for switch position, source availability, not in auto mode, and alert condition.​


No danger of the SERIES 300 ATS transferring loads to a dead source because the unique ASCO single-solenoid operator derives power to operate from the source to which the load is being transferred.
Integrated multilingual user interface for configuration and monitoring.
Adjustable time-delay feature prevents switch from being activated due to momentary utility power outages and generator dips

Services & Support


Frequently Asked Questions
How do I install the ATS?
The ATS should be installed following the procedure in the installation manual, wiring diagrams and the notes on the mounting diagrams
What generator models are compatible with the ATS?
The generator must be equipped with 2 wire start, and connected to the engine start circuit of the transfer switch.
How do I perform a transfer test?
Press transfer switch test button and hold it for 15 seconds or until the generator starts and a transfer occurs
Can I replace the ATS under warranty
Yes, as long as the switch is within the warranty period. Contact ASCO Power Warranty for guidance on procedure.
How do I contact a service technician?
Contact a local ASCO Services representative by calling the toll free hotline (1-800-800-2726), then go to option 2 then 3 on the prompt or connect with any customer service representative. They will transfer you to a local service technician’s office in your area.


Sales In USA Change Location
ASCO Power Technologies (Maryland, Southern Delaware, Washington DC and VA
Email Contact 571 313 8041 Fax 703 342 0391
12310 Pinecrest Road Suite 204 Reston Virginia 20191
Product areas of focus: Power Transfer Switches, Paralleling Switchgear, Power Control and Monitoring
Support Change Location
ASCO Services, Inc.
50 Hanover Road Florham Park New Jersey 07932
Product areas of focus: Power Transfer Switches, Paralleling Switchgear, Power Control and Monitoring


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