Power Transfer Switches

ASCO SERIES 300 Group G Service Entrance Power Transfer Switch

The ASCO SERIES 300 Group G Service Entrance Power Transfer Switch combines automatic power switching with the necessary disconnecting, grounding, and bonding required for use as service entrance equipment. The power transfer switch meets all National Electrical Code requirements for service entrance use.

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


Specifications per model ASCO SERIES 300 Group G Service Entrance Power Transfer Switch
Ampere Size Pole Count Voltage Enclosure Type Height (in / mm) Width (in / mm) Depth (in / mm) Weight (lbs / kgs)
70 - 3000 2, 3 115 - 600 Type 1, 3R, 3RX, 4, 4X, 12 48 - 96 / 1219 - 2438 36 - 41 / 914 - 1041 13 - 86 / 330 - 2184 400 - 2865 / 185 - 1329
* To view a specific model product page click on the model name above.


*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.


Suitable for use as service entrance equipment.
Listed to UL 891 (standard for switchboards) for 600 - 3000 amps, sizes and UL 1008 (standard for panel-boards) for 70 - 400 amps.
Automatic Transfer Switch is listed to UL 1008 for total system loads.
Sizes available from 70 - 3000 amps, 600 VAC, 50 or 60 Hz, single or three phase.
Ground fault trip protection provided on sizes 1000 amps and above.


Products 400 amperes or less, utilize
a single enclosure including a service (utility source) disconnect circuit breaker.
Products 600 amperes and above,
utilize a multi-section switchboard
construction including a service
equipment section containing the
service (utility source) disconnect
circuit breaker, grounding, and bonding provisions.

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 +1 571 313 8041 Fax +1 703 342 0391
12310 Pinecrest Road, Suite 204 Reston Virginia 20191 USA
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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