The total accumulated length of listed flexible metal conduit in neon tubing circuits should not exceed what length for bonding purposes?

The total accumulated length of listed flexible metal conduit in neon tubing circuits should not exceed 100 feet for bonding purposes. This specification is crucial because maintaining proper grounding and bonding is essential to ensure safety and minimize the risk of electrical shock or fire hazards. Beyond the 100 feet limit, the effectiveness of the bonding can deteriorate, as it may not adequately conduct fault currents back to the ground.

In the context of neon tubing circuits, the use of flexible metal conduit is intended to provide mechanical protection as well as electrical continuity. The 100-foot guideline ensures that the conduit maintains its bonding ability, which is necessary for the reliable operation of the neon lighting systems and adherence to safety standards.

Other lengths provided in the choices either understate the need for reliable bonding—potentially leading to safety issues—or do not align with the established industry standards that specify the 100-foot limit for these applications.