Mike Dolt Enterprises
Mike Dolt Enterprises
User: Barndog, Location: Spring Creek Pa
Asked on: Saturday, April 16, 2011 at 8:53 pm EDT
Answered on: Tuesday, May 14, 2024 at 4:16 am EDT
Question: We were talking in the shop the other day and My boss stated the fact that here you can run the service entrance cable around the house as far as you want or the same for a crawl space but you have to terminate the cable within 5 feet of entering the house. I was wondering if anybody had any insight on this rule. I was under the impresion that the reason they limited cable was because of lack of overcurrent protection at the utility transformer. If you can run 60 feet outside why cant you do they same indoors. I am in the north west corner of Pennsylvania.
NEC Requirements
The National Electrical Code (NEC) states the following about service-entrance cables: 230.9 Service-entrance conductors shall not be run within 5 feet of the inside wall of the building unless they are installed in a raceway. Article 820 Underground service-entrance cables shall be terminated within 24 inches of the outside wall of the building or structure.
RationaleLack of Overcurrent Protection
Service-entrance cables are not protected by overcurrent devices (circuit breakers or fuses) until they enter the building. This is because the overcurrent devices are typically located on the main electrical panel inside the building. Running the cable too far outside of the building would extend the unprotected length of the cable, increasing the risk of a fire or shock hazard.
Physical Protection
Service-entrance cables are designed for outdoor use and are more resistant to damage than wires used inside the building. However, running the cable too far inside the building could subject it to mechanical damage or exposure to environmental factors, such as moisture or heat, which could compromise its safety.
Code Exceptions
The NEC provides some exceptions to the 5-foot termination rule: If the service-entrance cable is installed in a raceway, it can be run further than 5 feet inside the building. If the service-entrance cable is installed in a crawl space that is not accessible for maintenance, it can be run up to 10 feet inside the building.
Additional Considerations
The rules governing service-entrance cables may vary slightly depending on the local electrical code. Always check with your local authority for specific requirements.
Conclusion
While it may seem counterintuitive to limit the length of service-entrance cables inside the building, these rules are in place for safety reasons. The risk of a fire or shock hazard increases when unprotected cables are extended too far beyond the point of overcurrent protection. Flag for review