Service Entrance & Distribution
Minimum service size, disconnect location, working space, service drop clearances, tap rules, fault current documentation, and arc flash labeling.
- State the minimum 100-amp service size for single-family dwellings
- Describe service disconnect location requirements and the six-handle rule
- Apply NEC 110.26 working space dimensions for electrical panels
- Identify minimum service drop clearances over driveways and public streets
- Explain the 10-foot and 25-foot tap rules for feeders
- Describe 2026 NEC arc flash labeling requirements with no 1,000-amp threshold
- Identify 2026 NEC Article 130 as the energy management systems article
Lección 1
Service Sizing, Disconnects & the Six-Handle Rule
Minimum Service Size
Per NEC 230.79, the minimum service size for a single-family dwelling is 100 amps. This has been the standard for decades and reflects the minimum needed for a modern home with electric cooking, air conditioning, and standard appliance loads.
While 100 amps is the code minimum, most new homes are installed with 200-amp service to accommodate modern loads including EV charging, heat pumps, and electric cooking.
Service Disconnect Location
Per NEC 230.70, the service disconnecting means must be installed at a readily accessible location nearest the point of entrance of the service conductors. The purpose is to provide a means to disconnect all power as close to the utility connection as possible, so firefighters and emergency responders can quickly de-energize the building.
Key requirements:
- Must be readily accessible - no climbing, moving obstacles, or using ladders
- Nearest the point of entrance - where service conductors enter the building
- May be installed inside or outside the building
- Must clearly indicate the on and off positions
The Six-Handle Rule
Per NEC 230.71, the service disconnecting means must consist of no more than six switches or six circuit breakers grouped together in a single enclosure or at a single accessible location. This is known as the "six-handle rule."
The purpose is to allow all power to be shut off with a maximum of six hand movements. A single main breaker satisfies this rule, as do up to six individual breakers serving as the service disconnect.
Exam Tip - Six Disconnects Maximum
When the exam asks "What is the maximum number of service disconnects?" the answer is 6. They must be grouped together so all power can be shut off with six hand movements or fewer.
The minimum service for a single-family dwelling is 100 amps per NEC 230.79. The service disconnect must be at a readily accessible location nearest the point of entrance with a maximum of 6 disconnects (the six-handle rule).