The minimum size bonding jumper for each FMC between a transformer and Panel LK is what size AWG?

The correct answer regarding the minimum size bonding jumper for flexible metal conduit (FMC) between a transformer and the panel is 2 AWG. This specification is based on the National Electrical Code (NEC), which provides guidelines for the proper grounding and bonding practices to ensure safety and system reliability.

When dealing with bonding jumpers, the primary concern is to ensure that they are sufficiently sized to carry potential fault currents without overheating or failing. The NEC outlines specific sizing tables that determine the minimum size conductors for bonding jumpers based on factors such as the size of the largest ungrounded conductor and the type of installation.

A size of 2 AWG is particularly important for ensuring that the bonding jumper can adequately handle the fault current and provide a low-resistance path back to the source, which is crucial for the operation of overcurrent protection devices. A smaller wire size may not have the capacity to effectively conduct the fault current, potentially leading to improper operation of protective devices and risking safety.

In contrast, sizes like 1/0 or 3/0 AWG, although they provide more capacity, are not required as a minimum under standard conditions for many residential and commercial applications. The specification of 1 AWG, while adequate for some smaller