Double lugged breakers?

Specific Inspection Topics Electrical Inspections
1

I received this email from a realtor about a report where I highlighted a double lug breaker in the service panel. I dn’t know where it was, how long agao it was or if he is even the seller or buyer agent.

I need some input on how you other fine inspectors are writing up this issue. Sorry I have no photos…

I am writing this to inform you, as I have numerous other home inspectors who write up the double lugging of circuit breakers, that this practice is not always incorrect. It has been, for many years now, an industry standard to install more than one wire on a circuit breaker designed to accept more than one wire. Of course, as you point out, the load on the circuit breaker may not exceed more than 80% of the circuit breakers rating. This practice of double lugging in certain situations is approved in the NEC and by all local jurisdictions.

This usage of double lugging is generally found to be used when there is two air handling units in a residence. These air handlers only operate small fan motors The loads, when both are put on one circuit breaker, have been designed so as not to exceed the maximum load of the circuit breaker.

I agree that double lugging is something that a home inspector should be looking for as a safety issue. But it is not always an improper installation as most home inspectors portray it to be.

Before I became a Facilities Operations Manager, I was a Master Electrician and have 30 years experience in the electrical field.

Thank you for your time.

Brian Britain | Operations Manager
PM Realty Group
JPMChase Account l Western Region
201 N. Central Ave. I MC: AZ1-3023
Phoenix, Arizona 85004
O 602-221-1375 I C 602-293-7638 I F 602-221-1077

brian.d.britain@jpmchase.com

2

There are breakers designed for two conducters per screw. That much is true.

3

. . . and if the breaker is not rated for two conductors, it is improper to attach two conductors - period.

4

There are certain manufacturers that do allow for two wires under one screw. I know Square D allows this. But it would have to be listed and labeled as such, and that could take some homework to figure out which boxes are acceptable and which ones are not.

5

These air handlers only operate small fan motors The loads, when both are put on one circuit breaker, have been designed so as not to exceed the maximum load of the circuit breaker.
**
Maybe he’s only worked on the units with no compressors…

He’s right…until he starts his third sentence. The OCPD can be rated according to the nameplate on the unit. Not necessarily what the wire is rated for on a motor load. Nowhere (that I know of) in the NEC does it say that doeble lugging is acceptable. Only by the blessing of the manufacturer, I believe this applies (square D for eg). He is also correct with the part of two motor loads and the rating of the OCPD. However, I believe this is only true when it is a tap and not referring to double lugging.

Somebody please let me know if I messed up here. And not based off of an opinion.

6

Thanks for your help. I’ll add another disclaimer when I find a double lug!
:stuck_out_tongue:

7

Here’s some good info:

Sep 20 2007

The House Detective by Barry Stone, Certified Building 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.

8

Thanks, Matt, that was clear and direct. I’ll change my wording to reflect that disclaimer.