Feeder Taps - Avoid feeling tapped out when trying to apply feeder tap rules

摘要

Sometimes, it makes sense to "tap into" a feeder conductor to power another conductor. From Art. 100, we know that a feeder conductor runs between service equipment (or a similar source) and the branch-circuit overcurrent protective device (OGPD). The conductor that's tapped into a feeder conductor is called the tap conductor. Think about this arrangement for a second. The OCPD supplies the feeder. You tap the feeder, making the feeder OCPD also the OCPD for the tap conductor. The OCPD is situated ahead of the point of supply to the tap conductor because it's situated ahead of the feeder. Normally, you have to size the OCPD for the size and insulation of a given conductor, per 240.4. But in this arrangement, the OCPD is sized for the feeder conductor and is thus oversized for that tap conductor (not sized per 240.4). In such a situation, you have a feeder tap [240.2].