diesel generators for sale
1-800-434-00031-305-592-6800Call Us Today
400 Amp Thomson Automatic Transfer Switch - 3 Pole - Commercial

400 Amp Thomson Automatic Transfer Switch - 3 Pole - Commercial


The following item(s) have been added to your cart.
You can now continue shopping or go straight to checkout

400 Amp Transfer Switch

Model - Thomson - Commercial

3 Pole - 120/240 Single

4 Wire - 120/208 3 Phase 

(480 Not available in this model)

Optional NEMA 3R Door Kit for an additional:  $285.00

Thompson transfer switches make use of a microprocessor based controller and a power contactor switching unit to automatically start a generator and transfer system load to the generator power supply, when a utility supply failure occurs.  Upon restoration of the utility power the automatic transfer switch will revert to the normal power supply. 

These switches are built for residential and light commercial applications.

Service Entrance Rated - Available for an additional: $2650.00

Power Contactor Switching Unit

  • Continuous current ratings for use with all load types
  • Works with copper and aluminum power cable connections

Solenoid Operated Transfer Mechanism

  • Fast operation allows in-phase power transfer
  • Electrical and mechanical interlocked mechanism prevents simultaneous closure of utility and generator sources

Superior Serviceability

  • Plug-in control devices allow easy field serviceability
  • Enclosed power contacts for sage operation and maintenance

Control Features

  • User programmable timers, simple LED interface
  • Outputs for Automatic Load Shed & Remote Alarming

Product Data

  • Rust resistant aluminum enclosures (NEMA 3R Optional)

  • Withstand short circuit current ratings up to 50kVA

Quality Assurance

  • ISO 9001 Registered Manufacturing Facilities

Safety Standards

  • UL 1008 Listed, Automatic Transfer Switches for use in optional standby systems

Specifications may vary. Confirm full specs prior to ordering.


Thomson Technology was formed in 1973 and is now one of the leading manufacturers of electrical products and systems for use in the Power Generation Industry. Thomson specializes in the design and manufacturing of power generation controls and switchgear for low and medium voltage applications. These transfer switches are needed for individuals who wish to use an electric generator as a source of backup power for a home or business. The switch safely switches the power source from the commercial power supply company to the local generator.

Transfer switches are the only recognized safe alternative for connecting an electrical load to the generator for an entire house or business. With hundreds of Transfer Switches in stock, Americas Generators can provide the ideal switch with your diesel generator purchase.

The Brand


Triton Generators is a world leader in the design, manufacture and distribution of industrial diesel generator sets from 10 to 2500 kW.


live chat service provider