How many 12 ga romex cables are allowed in a 3/4" NM connector?
Thanks.
Bill

 

Bill, many box connectors used in metal boxes for NM-B type cables have a min size rating either stamped on them or on the package they come in. Normally no more than two should be ran thru a clamp IMO and in some cases this is also stated by the manufacturer. It is very common to see on a 3/4" box connector (clamp) 8/2 awg min. or the like but 12/3, 10/3 and other combinations are acceptable. However, 12/2 cables generally speaking are better ran thru box connectors that go into 1/2" knockouts. Just need to properly size the cable to the box connector. If you must use a 3/4 knockout for 12/2 cable and dont want the large clamp they make reducing bushings that will allow a 1/2" connector to be used. These come in various styles. I prefer the threaded type that are installed using a set of lock nuts. The idea that as a box connector gets bigger so does the number of cables you can put into it is a missunderstanding. When you start puttting 3 or 4 cables in a connector you start running the risk of damaging the cables as you tighten the clamp or not being able to secure them properly. The connectors come in different sizes to primarily handle progressively larger cables. If the cable is round NM-B instead of flat NM-B one cable per connector is best.