Are equipment bonding jumpers required when a four-foot flexible metal conduit is installed in a rigid metal conduit run for a 30-ampere circuit?

In the context of electrical installations, equipment bonding jumpers serve the important purpose of ensuring electrical continuity and safety by providing a path for fault currents. However, specific requirements dictate when these jumpers are needed.

For a four-foot flexible metal conduit (FMC) installed within a rigid metal conduit (RMC) for a 30-ampere circuit, bonding jumpers are not required in this specific scenario. The National Electrical Code (NEC) recognizes that the rigid metal conduit provides a degree of grounding and bonding continuity. Since the area of concern is the short length of the flexible conduit (only four feet), and it is encased within a rigid conduit, which inherently offers substantial protection and grounding capability, an additional bonding jumper is unnecessary.

Thus, in situations where conduits are properly installed and sufficient grounding measures are already in place, bonding jumpers may not be mandated, making the correct response to the question one of non-requirement. The bonding jumper requirement generally applies under different conditions, such as longer conduits or when flexible conduits are used without rigid support.