What is the maximum distance within which RMC should be supported from each junction box?

The correct answer is 3 feet. In conduit systems, specific guidelines are established to ensure safety and reliability when installing raceways like rigid metal conduit (RMC). One crucial aspect of these guidelines is the support and securing of the conduit at junction boxes.

According to the National Electrical Code (NEC), RMC should be supported within a maximum distance of 3 feet from each junction box. This requirement is in place to prevent excessive strain on joints and connections, which could lead to failures over time or make the system vulnerable to physical damage.

Supporting the conduit adequately helps maintain the integrity of the electrical installation by ensuring that conduits remain properly aligned and secure. This practice not only contributes to the safety of the electrical system but also facilitates maintenance and reduces the risk of interruptions in service.