A reverse-fed breaker, or back-fed breaker, is a set up that is used on a small percentage of electrical panels. Normally, an electrical panel receives power through a main breaker installed near the top of the panel. On a reverse-fed panel, the wires that bring the power into the panel are connected to a breaker which is then attached to the panel and looks just like any other breaker in the panel. In fact, if there were no retaining screw holding it in place, it would be difficult for someone to even know that the back-feeding breaker is not just another regular breaker in the panel.
How Does a Back-Fed Breaker Work?
In a back-fed breaker, the wires that are bringing the power into the panel are connected to the back-fed breaker just like they are connected to any other breaker. This means that the power is going backward through the back-fed breaker and then to the main bus to energize the main bus which will then provide the power to the other breakers in the panel. In the photo on the right, the arrows mark the wires that are supplying power to the panel via the back-fed breaker.
Why is a Retaining Screw Required on a Back-fed Breaker?
If this back-fed breaker were to ever come loose from the panel, it would remain energized and be “swinging” in the panel thus creating a dangerous situation. For this reason, all back-fed breakers are required to be securely attached to the panel. This is normally accomplished using a retaining screw. (You can see this screw in the photos above.)
© 2020 Mike Morgan
This article was written by Mike Morgan, the owner of Morgan Inspection Services. Morgan Inspection Services has been providing home, septic and well inspection services throughout the central Texas area since 2002. He can be reached at 325-998-4663 or at email@example.com. No article, or portion thereof, may be reproduced or copied without prior written consent of Mike Morgan.