New York State Master Electrician Practice Exam 2026 - Free Electrician Practice Questions and Study Guide

The minimum conductor distance for Type 3 surge protective devices from the service disconnect is 30 feet. This requirement is established to reduce the risk of transient voltages and to enhance the performance of the surge protective device (SPD).

When surge protective devices are installed at the service disconnect, maintaining an adequate distance between the SPD and the disconnect minimizes the potential for voltage surges to reach sensitive equipment. The 30-foot distance ensures that there is sufficient length of conductor, which helps to dissipate surge energy more effectively and prevents it from affecting the entire electrical system.

Additionally, this distance helps to comply with the National Electrical Code (NEC) and manufacturers' recommendations, which often dictate the manners of installation and the placement of surge protectors in relation to the service disconnect to achieve optimal protection. By following these guidelines, electricians can better safeguard equipment against electrical surges caused by lightning strikes, switching events, or other disturbances in the electrical system.