DEFECT: Double Tapped Circuit Breaker
A double tapped circuit breaker is a circuit breaker that has two wires or circuits connected to a single lug. While this is a commonly mentioned item on home inspection reports, it is often reported in error. The misconception is that every double tapped circuit breaker is a defect, this is not true. Some manufacturers design their breakers to allow two wires to be connected to a single breaker. Typically it states on the breaker if this is allowed or not, you may also have to read the product specifications for that particular breaker.
In the Phoenix area we see allot of “Square D” brand electrical panels, the majority of Square D breakers are designed to allow two wires to be connected to a single breaker. These breakers have a specially designed wire lug with an area for each wire. Cutler Hammer also makes a type of breaker that allows the connection of two wires, the CH115 which is a 15 amp breaker. There are also additional restrictions placed by the manufacturers. Square D allows one aluminum wire only or two copper of the appropriate wire gauge and both wires have to be the same gauge.
If a circuit breaker is not specifically designed to accommodate two wires then it is improperly double tapped and this is a defect. Hot spots can occur at the lug due to improper contact and torque because of the second wire, this can lead to arcing.
There are two options to repair an improperly double tapped circuit breaker. If there is additional space in the electrical panel an additional circuit breaker can be installed for the second wire. If there is no room left for an additional breaker, a single wire (pigtail) can be attached to the breaker and the other two wires attached to that with a wire-nut. Whichever method is used, I recommend this be done by a licensed electrical contractor to ensure that it is done properly.