110.27 Guarding of live parts
Live parts operating at 50 V ac or 100 V dc up to 1000 V ac or 1500 V dc are guarded against accidental contact: rooms or enclosures accessible only to qualified persons, permanent partitions or screens, elevation above the floor or working surface, or similar arrangements. Where equipment is exposed to physical damage, guards or enclosures protect it.
110.28 Enclosure types
The enclosure is selected for the actual environment. Table 110.28 covers rain, snow and sleet, windblown dust, hosedown, corrosive agents, temporary or prolonged submersion, oil or coolant, and dust, lint, fibers and flyings. Typical examples:
Type 3R: common outdoor rain protection.
Type 4 and 4X: hosedown; 4X adds corrosion resistance.
Type 6 and 6P: temporary or prolonged submersion.
The table controls suitability, not the catalog phrase “outdoor rated.”
110.29 In sight from
Where the NEC requires equipment to be “in sight from,” “within sight from” or “within sight of,” it must be visible and not more than 50 ft away. This most often controls disconnecting means.
Why it matters in South Florida
On coastal Miami roofs and garages, corrosion is the exposure a standard 3R enclosure does not address. Look at the corrosion-resistant types (the “X” types such as 4X) for rooftop disconnects, condensing-unit disconnects and equipment within salt-spray reach, and check the washdown and submersion columns for kitchens, pump rooms and below-grade spaces.
Do
Guard live parts from accidental contact.
Select the enclosure type for the real environment.
Verify “within sight” means visible and within 50 ft.
Do not
Use “outdoor rated” as a substitute for enclosure selection.
Assume all enclosure types give the same protection.
Ignore corrosion, washdown, dust or submersion exposure.
Field tip
For each piece of equipment ask four questions: can someone touch energized parts, what is the actual exposure, which enclosure type addresses it, and is the disconnect visible and within 50 ft? Related: electrical environment · wet locations. Next: #027 — NEC 110 Over 1000 V, Tunnels & Manholes.
Code basis
NEC 2026 Article 110.27–110.29 education from the owner-provided Daily Code Talk. Confirm the locally adopted NEC edition, Table 110.28 and amendments. Not an enclosure selection for your project.