Is an equipment bonding jumper required to be installed inside or outside of flexible metal conduit in a hazardous location?

In hazardous locations, the installation of an equipment bonding jumper is crucial to ensure safety by preventing any potential electrical hazards. The purpose of the bonding jumper is to provide a low-resistance path for fault currents, which helps to prevent dangerous voltages from appearing on non-current-carrying metal parts of equipment.

In the case of flexible metal conduit, it's important to consider how it serves as a grounding path. Installing the bonding jumper inside the conduit may not provide adequate grounding effectiveness due to the flexible nature of the conduit creating potential breaks in the grounding path. Therefore, having the bonding jumper installed outside of the flexible metal conduit ensures better reliability and continuity of the bonding path, which is essential in preventing electrical shock or equipment failure in hazardous locations.

Moreover, regulations, such as the National Electrical Code (NEC), highlight the necessity of effective grounding and bonding methods, particularly in environments deemed hazardous due to the presence of flammable gases, dust, or vapors. This reinforces the requirement for an equipment bonding jumper to be properly installed to maintain a safe working environment.