Working Space Entrance & Egress Calculator
Check the NEC 110.26(C) entrance and egress rules for an electrical working space. Enter the equipment rating and width and the tool tells you whether an exit is required at each end, the minimum entrance opening, and whether the personnel door needs panic hardware.
How to use this calculator
- Enter the equipment ampere rating. For grouped 230.71 service disconnects, use their combined rating.
- Enter the equipment width in inches. Over 6 ft wide means over 72 in, which is one of the two large-equipment thresholds.
- Leave "contains overcurrent, switching, or control devices" checked for a panelboard, switchboard, switchgear, or motor control center. The 110.26(C)(2) and (C)(3) rules apply only to that kind of equipment.
- Check the egress boxes that apply: a continuous, unobstructed way of egress travel, and whether a personnel door sits within 25 ft of the nearest edge of the working space.
- Optionally enter the working-space depth, voltage to ground, and Condition to test the twice-the-depth allowance for a single entrance.
- Read the number of entrances required, the minimum entrance opening, and the panic-hardware result.
NEC reference
This calculator implements NEC 2020 110.26(C). Section 110.26(C)(1) requires at least one entrance of sufficient area. Section 110.26(C)(2) requires an entrance at each end of the working space, each at least 24 in wide and 6.5 ft high, for equipment that contains overcurrent, switching, or control devices rated 1200 A or more and over 6 ft wide, with a single entrance allowed for a continuous unobstructed egress path or where the depth is twice the 110.26(A)(1) value. Section 110.26(C)(3) requires a personnel door within 25 ft of the nearest edge, at 800 A or more, to open in the direction of egress with listed panic hardware or listed fire exit hardware. The 110.26(A) working space, the 110.26(E) dedicated equipment space, and over-1000 V equipment (110.34) are out of scope here.
Results are for reference only. Verify against the applicable adopted edition of the NEC and consult a licensed electrician for code compliance.
The two large-equipment thresholds (110.26(C)(2))
The two-entrance rule is the most misread part of 110.26. It applies only when the equipment clears both thresholds at once, not either one alone. A 2000 A switchboard that is only 4 ft wide does not trigger it; neither does an 8 ft wide 800 A panel.
| Threshold | Value | Note |
|---|---|---|
| Rating | 1200 A or more | The equipment rating, or combined 230.71 disconnect rating |
| Width | over 6 ft (over 72 in) | Strictly more than 6 ft; exactly 6 ft does not count |
| Entrance size | 24 in wide by 6.5 ft high | At each end of the working space when both thresholds are met |
When both thresholds are met, one entrance is required at each end of the working space. A single entrance is permitted only where the location gives a continuous, unobstructed way of egress travel, or where the working-space depth is twice the 110.26(A)(1) requirement with the entrance edge nearest the equipment at least that clear distance away.
The 800 A personnel-door rule (110.26(C)(3))
This rule is separate from the two-entrance trigger and uses a lower rating. Where equipment rated 800 A or more is installed and a personnel door intended for entrance to and egress from the working space is less than 25 ft from the nearest edge, the door must open in the direction of egress and carry listed panic hardware or listed fire exit hardware, so a worker can push out even with both hands full or in the dark. The 2020 NEC dropped this threshold from the earlier 1200 A to 800 A.
Worked example: a 2000 A switchboard lineup
Take a 2000 A switchboard that is 8 ft (96 in) wide. It is rated over 1200 A and is over 6 ft wide, so 110.26(C)(2) requires one entrance at each end of the working space, each at least 24 in wide and 6.5 ft high. If the working space in front is 480 V to ground in Condition 3, the 110.26(A)(1) depth is 4 ft. Provide 8 ft of depth, twice that figure, with the entrance edge nearest the gear at least 4 ft away, and a single entrance is permitted instead. Because the board is also 800 A or more, any personnel door within 25 ft of the working space must open in the direction of egress with panic hardware.
Change the board to 1000 A and nothing in 110.26(C)(2) applies: it is under 1200 A, so one entrance of sufficient area meets 110.26(C)(1). The 800 A door rule still applies at 1000 A, so the panic-hardware requirement carries over.
Common mistakes
- Treating the two thresholds as either/or. Both the 1200 A rating and the over-6-ft width must be met before the two-entrance rule applies.
- Reading 6 ft as the trigger. The rule says over 6 ft. Equipment exactly 6 ft (72 in) wide is not over 6 ft.
- Using the 1200 A number for the door. Panic hardware keys off 800 A, not 1200 A, in the 2020 NEC.
- Confusing entrance with working space. 110.26(C) is how you get in and out; 110.26(A) is the clear space in front and 110.26(E) is the dedicated space above. They are three separate rules.
Frequently asked questions
When does equipment need two entrances to the working space?
Under 110.26(C)(2), equipment with overcurrent, switching, or control devices needs an entrance at each end when it is rated 1200 A or more and is over 6 ft wide. Both must be true. Each entrance is at least 24 in wide and 6.5 ft high.
When is a single entrance allowed for large equipment?
Where the location gives a continuous, unobstructed way of egress travel, or where the working-space depth is twice the 110.26(A)(1) minimum with the entrance edge nearest the equipment at least that clear distance away.
What is the minimum size of a working-space entrance?
For large equipment each required entrance is at least 24 in wide and 6.5 ft (about 78 in) high. For other working spaces 110.26(C)(1) requires at least one entrance of sufficient area; the 24 in by 6.5 ft opening is the practical minimum.
When does an electrical room door need panic hardware?
At 800 A or more, where a personnel door is within 25 ft of the nearest edge of the working space, that door must open in the direction of egress and have listed panic hardware or listed fire exit hardware (110.26(C)(3)). The 2020 NEC lowered this from 1200 A to 800 A.
Is this the same as the 110.26(A) working space?
No. 110.26(A) sizes the clear space in front of the equipment; 110.26(C) governs getting in and out of that space; 110.26(E) is the dedicated space above it. This tool covers only 110.26(C) entrance and egress.
Related calculators
- Working Space Clearance Calculator: the 110.26(A) depth, width, and headroom of the clear space in front of the equipment.
- Dedicated Equipment Space Calculator: the 110.26(E) space above a switchboard, panelboard, or MCC kept clear of piping and ducts.
- Service Size Calculator: size the service disconnect, conductors, and grounding electrode conductor for the equipment.
- Service Disconnect Calculator: the 230.71 number of service disconnects and their minimum rating.
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