Whats the deal with wire tuts? Sometimes when im tightening them they just break off the wire at the insulation. Am I just being to cautious by tightening them to tight or should they just be snug? I have a fear they will fall apart if i dont get them nice and tight.
well lots of things can cause a wire to snap of @ the insulation. you may be overtightening the twist; when turning the wirenut onto the wire, you should stop 3 full turns AFTER the wirenut stops spinning free on the wires and the whole bundle of wires starts to turn. there is such a thing as overtightening the wirenut!
also when working on old wires/junctions, the old exposed copper should be cutoff and the wire restripped, because a wire that has sat 'twisted' under a wirenut for several years will lose its ductility (flexability) and become brittle due to the mechanical pressure of the wirenut itself and the constant vibration of current through the wire (yes, a/c current makes wire vibrate, even though the vibrations are very small themselves, it does happen. that is why tight strong connections with plenty of slack is always stressed so strongly, the wire will literally work itself loose due to these vibrations)
another thing is your wire may be old and brittle, or the tool you are using to strip the wire maybe cutting through the insulation and into the copper, which will cause the wire to snap off at the insulation...
make sure your using the proper size and type of wirenut as well, and always twist to the right, never to the left.
a technique that helps when using wirenuts is to 'pre twist' the wires together using a pair of sturdy pliers or side cutting pliers (kleins). that way you have a good strong joint before you ever start put the wirenut on... this is actually the preferred method taught to apprentices in the field