A connector is rated for what material it accepts, what sizes, and how many conductors at once. All three have to match before it fits anything.
Connectors are the most casually chosen part on a job and one of the easiest to get wrong, because the wrong one goes on and looks exactly like the right one.
Three separate checks, and failing any one of them is a failed connection. Material is the first -- the copper and aluminum lesson again. Size is the second. The third is the one people skip: how many conductors this connector is rated to join, and which combinations of size are allowed inside it. Two of one size is not the same rating as one of each of two sizes.
Check yourself: A wire connector goes onto the conductors without forcing. Is it suitable?
Answer: Not necessarily. A connector that fits physically may still be unsuitable.
Fit is mechanical. Suitability is the material, the sizes, the number and combination of conductors, and the installation instructions -- none of which you can feel by twisting it on.
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Written from the owner's poster for this lesson. Nothing added beyond what the poster states.
Written for Texas apprentices as free study material. The Texas apprentice licence is an application, not an exam (Occupations Code 1305.161), and nothing here counts as apprenticeship hours or continuing-education credit. VoltMark is not affiliated with, endorsed by, or sponsored by NFPA, PSI, TDLR, or any state or local licensing authority. Always follow your employer's safety programme and your supervising electrician.
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