Mike Dolt Enterprises
Mike Dolt Enterprises
User: bflaaen, Location: New Jersey
Asked on: Monday, December 9, 2024 at 11:20 am EST
Answered on: Thursday, March 6, 2025 at 6:03 am EST
Question: We have a new MCC installation going in and there is going to be a new 5'x5' floor hatch put in the floor to allow the owner to be able to pull a pump from the lower level of the building for replacement. The clearance in front of this MCC is more than adequate except for the new floor hatch. The distance from the front of the MCC to the edge of the floor hatch is 2'-6". The floor hatch sits essentially level with the floor - there is no curb or other obstructions around it. It has a door that is adequately rated for personnel loads. Is the floor hatch permitted to be within the working space?
This is a classic NEC (National Electrical Code) working space question. Let's break down the relevant code sections and apply them to your situation.
NEC 110.26 Working Space About Electrical Equipment
This is the key section. It dictates the clearances required in front of electrical equipment like your MCC. 110.26(A) Dimensions
This subsection specifies the required depth of the working space based on voltage to ground and conditions. Your situation describes adequate working space except for the hatch.
110.26(B) Clear Spaces
This subsection says working space must be kept clear. Here is what is relevant for you: "The working space required by this section shall not be used for storage." This says absolutely nothing about a floor hatch
110.26(C) Entrance to and Egress from Working Space
This subsection addresses entrances and exits. This isn't really about the obstruction within the working space itself.
110.26(D) Illumination. This says nothing about hatches or obstructions. 110.26(E) Headroom
This subsection requires sufficient headroom in the working space. This isn't about floor obstructions.
Analysis
The core issue is whether the floor hatch is considered an obstruction that violates the clear space requirement. Here's the breakdown:1. It's Flush and Rated
You stated the hatch is flush with the floor and rated for personnel loads. This significantly mitigates the hazard of tripping.2.
Not Storage
You aren't using the working space for storage.3.
Distance
2'6" is tight, but if you are under 150V to ground and condition 1, 2'6" may be adequate. If not it would violate 110.26(A).
Conclusion
A key here is that the NEC does not specifically prohibit a floor hatch in the working space and the hatch is flush with the floor, rated for personnel loads and the working space complies with 110.26(A) then the installation would likely be deemed to be compliant.
Disclaimer: This analysis is based on the information provided and a general understanding of the NEC. Local interpretations and specific AHJ (Authority Having Jurisdiction) rules can vary. Always consult with your local electrical inspector for a definitive ruling before proceeding with the installation.* Flag for review