408.3(D) Terminals.

The terminals in the right side picture can be accessed without reaching across the uninsulated, ungrounded busbars but only if proper working space has been provided behind the switchgear. In this case, it hasn’t which forces the electrician to either lose weight in order to squeeze back there or reach across uninsulated ungrounded busbars from the front.
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The terminals in the right side picture can be accessed without reaching across the uninsulated, ungrounded busbars but only if proper working space has been provided behind the switchgear. In this case, it hasn’t which forces the electrician to either lose weight in order to squeeze back there or reach across uninsulated ungrounded busbars from the front.

Code Change Summary: Requirements for access to terminals within switchboards, switchgear and panelboards have changed.

The previous language in the 2014 NEC® required load terminals for field wiring, including grounded and equipment grounding terminals to be located so that they can be accessed without reaching across or beyond an uninsulated ungrounded “line” bus in order to make connections.

There is no definition of “line” in the NEC® but it is a common term used in the electrical industry used to describe the side where power comes in. In switchboards, switchgear and panelboards, the word “line” can be confusing, especially if there are other interconnected power systems backfeeding the equipment, such as a PV system.

The word “line” really isn’t what’s important here. The intent of the section is to ensure that adequate room is provided within switchboards, switchgear and panelboards so that the electrician can get to all terminals without reaching across uninsulated, ungrounded bus in order to make connections.

Below is a preview of the NEC®. See the actual NEC® text at NFPA.ORG for the complete code section. Once there, click on their link to free access to the 2017 NEC® edition of NFPA 70.

2014 Code Language:

408.3(D) (D) Terminals. In switchboards, switchgear, and panelboards, load terminals for field wiring, including grounded circuit conductor load terminals and connections to the equipment grounding conductor bus for load equipment grounding conductors, shall be so located that it is not necessary to reach across or beyond an uninsulated ungrounded line bus in order to make connections.

2017 Code Language:

408.3(D) (D) Terminals. In switchboards, switchgear, and panelboards, load terminals for field wiring, including grounded circuit conductor load terminals and connections to the equipment grounding conductor bus for load equipment grounding conductors, shall be so located that it is not necessary to reach across or beyond an uninsulated ungrounded bus in order to make connections.

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408.3(D) Terminals.

Below is a Real Question from our Electrical Continuing Education Courses for Electrical License Renewal:

Which of the following is true for switchgear terminations?

A: Field wiring shall be so located so that it can be accessed without reaching across line side bus.
B: Line terminals for field wiring shall be so located that it is necessary to reach across an uninsulated ungrounded bus to make connections.
C: Load terminals for field wiring shall be so located that it is NOT necessary to reach across or beyond an uninsulated ungrounded bus in order to make connections.
D: Field wiring shall be so located so that it is necessary to reach across load side bus in order to make connections.
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