The House Detective by Barry Stone, Certified Home Inspector
Dear Barry: The home inspectors in my area, myself among them, have an ongoing debate with local electricians. When we see two wires connected to a circuit breaker, we report this as “double-tapping.” As far as I know, only Square D brand type QO breakers are approved for use with two wires, but the electricians say it’s OK with other brands as well, such as Cutler-Hammer type CH breakers. But when I checked the Cutler-Hammer website, I found nothing about double-tapping being OK with their breakers. To make matters worse, some of the electricians in my area seem openly hostile toward home inspectors and say that we are clueless on this and other issues. Could you please provide some clarity on this point of contention? Stephen
Dear Stephen: Disagreements between home inspectors and contractors are common, occurring not only with electricians, but with experts in plumbing, roofing, fireplaces, furnaces, framing, etc. Sometimes home inspectors are correct, and sometimes they are not. All participants in these debates should therefore be open-minded, mutually respectful, and humble in their approaches to one another.
In determining when double-tapping is or is not acceptable for a particular circuit breaker, a simple rule of thumb is to check the design of the connecting hardware at the breaker. If the hardware is specifically shaped to accommodate two separate wires, as with Square D type QO breakers, then the connection is acceptable and should not be cited as double-tapping in a home inspection report. But if the connecting hardware is a simple screw or lug, it is reasonable to assume that the manufacturer of the breaker intended there to be one wire only at the connection. In that case, double-tapping would be the proper disclosure for a home inspector. The only way to connect two circuits to a single breaker in that instance would be by indirect means. The accepted method would be to connect a short wire (known as a “pigtail”) to the breaker and to join the other end of that wire to the two circuit wires with an appropriate connector, such as a wire nut.
To avoid future disagreements over double-tapping issues, it may be necessary to change the wording of your disclosures. For example, if you find what appears to be a faulty double-tap, your report might say, “Double-tapping was observed in the main breaker panel. These breakers may not be rated for double-tapping. Therefore, further evaluation by a licensed electrician is advised.”
This wording allows you to report a possible defect and to recommend attention by a qualified expert — in this case an electrician. You haven’t said the condition is definitely defective but simply that it is questionable and warrants further evaluation by a specialist. If the electrician determines that the connection is acceptable, he assumes future liability for the correctness of that verdict. And your disclosure would be no worse that that of the family doctor who recommends a heart specialist to evaluate an cardiac symptom. If the specialist concludes that the heart is perfectly healthy, the patient will be relieved and unlikely to fault the general practitioner for erring on the side of caution.