Twinsource Transfer Switch LogoRack-Mount Transfer Switches & Dual Cord Conversion Devices


Our Products: (click on each for technical info)


TwinSource Rack-Mounted Automatic Transfer Switches Provide the Highest Reliability of Electrical Supply at 7x24 Mission Critical Facilities For Protection of Single Cord, Dual Cord, and Triple Cord Electronic Loads

rackmount static switch with plug-in electronics photo

30 - 50A DCC-II Rackmount Static
Transfer Switch with Plug-in Electronics
learn more about rack-mount static switch

TwinSource manufactures rack-mount automatic transfer switches in both solid state (single phase and three phase) and electromechanical (single phase) versions.

  • The solid state or static DCC-II transfer switch has been our flagship product for over 10 years and is a two pole single phase device available in ratings of 30, 40, and 50A (10KW) in all worldwide voltages and frequencies. A 3 phase, 4-wire, 4 pole version has just been introduced as well that comes in 208/120V (US Applications Only), 50A, 18KW for higher power 3 phase situations. 4 pole is necessary to also disconnect/reconnect the source neutrals in a transfer.
  • The solid state or static DCC-III transfer switch is a four pole three phase device available in the rating of 50A @ 208/120 volts, (18KW), only for the North American market at this time with 230/400V version planned for later.  4th pole is necessary to disconnect & reconnect the source neutrals in a transfer.
  • The electromechanical DCC-I units are available in a 24A rating in all worldwide voltages.

These systems all operate on the basis of powering your critical load from a preferred source and in the event that source falls outside your pre-set specifications, then the system transfers the load to the alternate supply automatically. It does this quickly in less than 1/4 cycle for the SCR based system and in less than 1/2 cycle for the electromechanical version, all without any risk of dropping the load or cross connecting the sources. The Preferred Source can be selected by a simple push of a button, remotely through the RS 485 port, or through a settings selection.

The TwinSource Rack Mount Static Transfer Switch is considered “Best in Class” among rackmounted automatic transfer switch products. It has a proven track record of over 60,000,000 hours on line without a load failure among its installed base worldwide. We have systems across the globe mostly populated in US, UK, Singapore, Korea, Hong Kong, Dubai, and other locations. For more information on the products please refer to the corresponding tabs above. This web site also offers a general tutorial on all ratings and types of transfer switches which you will find very informative.

Our systems are utilized in the following applications to maintain critical equipment worldwide:

  • Major Data Centers
  • Remote Satellite Operations
  • Financial & Banking Operations
  • Hosting Sites
  • Network Operations Centers
  • Fiber Optic Nerve Centers
  • Air Traffic Control Centers
  • Military Command & Control
  • Petrochemical Plants
  • Semiconductor Fab Plants
  • Process Control
  • Power Plants
  • Security Systems
  • Communications


[Photos of typical sites where rack mounted static transfer switches are used due to criticality of their operations.]

rack-mount static switch application photo

rackmount static transfer switch photo

rackmounted static transfer switch application photo

rackmount automatic static transfer switch application photo

rack-mount automatic static transfer switch application photo

Stand alone static transfer switches photo

rack-mounted static transfer switches photo

TwinSource USA • 32333 Aurora Road • Solon, Ohio, 44139, USA • (216) 408-2888
Contact: Fred Tamjidi • All sales inquiries: • Technical inquiries:

All specifications subject to change at supplier discretion without advance notification.

Types of Rack-Mount Transfer SwitchesTypical Installation of RM Transfer SwitchesBenefits of Static Transfer Switches
Implementation of Rack Mount Static Automatic Transfer SwitchesOverview of Automatic Transfer Switches
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