Just curious, how many of you guys and gals use electrical tape on a wirenut? In my opinion I never use it. My theroy is if the wirenut is correctly installed it will not have a need for tape. If there are bare wires exposed then you have the wrong wirenut. If you don't want the wirenut to come off in the box then you did not install it correctly. Maybe it is just me but I dispise going into a box to troubleshoot and find all the connections taped. URGH! Maybe I'm wrong, it won't be the first time.
IMO taping wirenuts is a hold-over from the old Knob & Tube days when all splices were twisted, soldered and taped. The old-timers would tell the young pups they had to tape to do a good job. Us young pups became the old-timers, and the idea is still there. Wirenuts today will do the job just as fine, with or without tape. If you're worried about vibration, dirt, or something, go ahead and tape for your peace of mind. But maybe, your enclosure or termination device is not really appropriate for the purpose or conditions of use. Maybe????
I've never taped a wire nut, as I don't see the logic in doing so. I have, however, troubleshot or added to circuits with taped wire nuts, and it is miserable getting the sticky black goo all over your hands.
Sven, You brought up a good point, on when you might use tape. If you are working on an older system that used rubber or cloth covered insulation, then use all the tape required to make it a safe repair. As noted most of the old timers would say "Don't forget to tape it up good", and with good reason.
Sven, LK, Agreed. Use tape where necessary, of course. In the case of old BX and K&T a sleeve is almost a must. In the case of regual NMC I have seen poor splices using a wirenut AND tape and the wirenut still falls off. Connecting stranded and solid also requires a bit of re-assurance. But I've talked to electricians all the time that always do it and I can't get a good explaination as to why other than that is what I was taught. Thanks for the feedback.