1. North Carolina Department of Insurance Office of State Fire Marshal
Risk Management
State Electrical Division
2017 State Electrical Code
230.70(A)(1) - Length of
Service-Entrance Conductors

2. Notice:
The following illustrations are approved by the State Electrical Division of the North Carolina Department of Insurance, Office of State Fire Marshal. These illustrations are intended to demonstrate but not supersede the official written interpretations found at the following web address:
Joseph Starling
Chief State Electrical Engineer & Inspector
Illustrated by:
Danny Thomas
State Electrical Inspector

3. Service-Entrance Conductors Date: June 12, 2018 2017 Electrical Code
Disconnect
Date: June 12, 2018
2017 Electrical Code
Subject: Length of Service Entrance Conductors
Section (A)(1)
Question:
What is the maximum allowed distance the service-entrance conductors may enter a building or structure?

4. Date: June 12, 2018
2017 Electrical Code
Subject: Length of Service Entrance Conductors
Section (A)(1)
Answer:
Section (A)(1) states that “the service disconnecting means shall be installed at a readily accessible location either outside of a building or structure or inside the nearest point of entrance of the service conductors.” The electrical code does not define a distance for the service conductors once such conductors enter a building or structure.
The language of (A)(1) has been virtually unchanged over the last several decades. What is commonly known as the “Barringer Rule” or “Five Foot Rule” has been the standard for evaluation of service-entrance conductors inside a building or structure in North Carolina for many decades. The Rule remains as the State’s position for proper evaluation in determining the maximum allowed distance service-entrance conductors may enter a building or structure.

5. Date: June 12, 2018
2017 Electrical Code
Subject: Length of Service Entrance Conductors
Section (A)(1)
The current version of the “Barringer Rule” or “Five Foot Rule” is as follows:
Service-entrance conductors shall be in compliance with the requirements of (A)(1) when routed from their point of entrance into a building or structure to the point of attachment to the service disconnect enclosure under all of the following criteria:
1. In the most direct route or at right angles;
2. Horizontally not more than twice the nominal width of the service disconnect enclosure; and
3. Vertically not more than twice the nominal height of the service disconnect enclosure or five (5) feet, whichever is greater.
Service entrance conductors in excess of these specified limits will not be allowed unless specifically authorized by special permission from the electrical inspector having jurisdiction to accommodate adverse site conditions which would not reasonably allow installation with this criteria.

6. Service-Entrance Conductors
Date: June 12, 2018
2017 Electrical Code
Subject: Length of Service Entrance Conductors
Section (A)(1) ON
OFF
Service Disconnect
Service-Entrance Conductors
Must be:
1. In the most direct route or at right angles
Meter
Service-Entrance Conductors

7. Service-Entrance Conductors
Date: June 12, 2018
2017 Electrical Code ON
OFF
Service Disconnect
Horizontal
Length Cannot Exceed
Width X 2
Service-Entrance Conductors
Subject: Length of Service Entrance Conductors
Section (A)(1)
Service-Entrance Conductors
Must be:
Meter
2. Horizontally not more than twice the nominal width of the service disconnect enclosure

8. Service-Entrance Conductors
Date: June 12, 2018
2017 Electrical Code
Vertical Length Cannot Exceed Height of Disconnect X 2 or 5 feet, Whichever is Greater ON
OFF
Service Disconnect
Subject: Length of Service Entrance Conductors
Section (A)(1)
Service-Entrance Conductors
Must be:
Meter
3. Vertically not more than twice the nominal height of the service disconnect enclosure or five (5) feet, whichever is greater