Featured Technology:
Anti-BACKFeed Circuit Breaker

LEARN MORE  Market Need | Features | Technology Description | Availability | Product Contacts

Market Need

The North American residential electric generator market is more than a $380 million per year industry and is growing stronger every year. Over ten million households in the U.S. have at least one generator, and millions more are purchased annually. In fact, American’s purchased more than three million generators in the year following Hurricane Katrina. Many of today’s household and business “always on” technologies -security systems, computers, and automated utility controls- are driving an increased dependence on quality, uninterrupted power. At the same time, serious concerns about the reliability of this much-needed commodity are increasing, fueled by more frequent outages. Along with a continued demand, there has also been a growing interest in higher wattage and more powerful generators.

Many homeowners have already purchased a portable generator, but have not taken the time to safely wire it into existing circuits.  By directly connecting the generator into the home’s existing wiring, the homeowner has the flexibility to select only the devices or rooms to be powered using the breakers already installed in the residential panel.  If connected without the necessary safety precautions; however, the electricity produced by the generator can feed back into the commercial power grid. This unexpected flow of electricity creates a deadly hazard for electrical servicemen working on the system. Ironically, because of the direct correlation between power outages and generator usage, it is precisely at the time a generator is pumping dangerous currents into the system that a lineman would be servicing the lines. This danger is increasing with the rising use of higher wattage generators and the increased frequency of interruptions. 

Systems currently available and designed to combat “backfeeding” are costly and complex. Many residential generator owners do not purchase these systems or choose to illegally connect their generator due to the immediacy of their situation in the case of power loss.

Anti-Feedback Circuit Breaker: Picture 3Features

  • Mechanical interlock protects commercial power grids from generator backfeed
  • Easy to retrofit into existing residential circuit panels
  • Potential usage in marine and alternative energy (wind, battery) installations
  • Offers simplicity of use for the homeowner
  • Offers potential for becoming an electrical code requirement
  • Internal design tailored for ease of manufacture
  • Tested under load; UL approval pending licensing rights


Technology Description

An engineer at the JHU/APL has created a simple and cost effective solution to prevent the dangers of backfeeding.

Based on a simple, double pole, double throw design, the anti-feedback circuit breaker offers failsafe isolation of generator power from the commercial main power. Through manual switches, users are able to easily break the connection to the municipal power lines and select power flowing in from the generator. Mechanical interlocks eliminate the possibility of electricity flowing from the generator into the power grid.

This circuit breaker is compatible with existing residential units and can be easily installed. It will provide the function of a main circuit breaker whether or not a generator is connected.


This technology is currently available for licensing.

Product Contacts

Licensing Information:

Ed Chalfin
443/778-7473 (Baltimore Metro Area)
FAX: 443/778-5882


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