/ Field knowledge · NEC 100 · Sparky Edition
“We can get to it somehow” is not a design criterion.
NEC Article 100: “we can get to it somehow” is not a design criterion. Accessible and readily accessible are different words. The governing requirement decides which one applies.
Educational 2026 NEC Article 100 terminology. Confirm the adopted edition. This is not a working-space calculation and does not invent 110.26 dimensions. Distinct from IMC 306 mechanical access.
- Accessible equipment can be approached without barriers that effectively prevent access. Accessible wiring methods can be exposed or removed without damaging the building structure or finish.
- Readily accessible equipment can be reached quickly for operation, inspection, or servicing without using tools other than keys, climbing over or under obstacles, moving obstacles, or using a portable ladder.
For disconnects serving RTUs, AHUs, pumps, VFDs, and control equipment, distinguish physical reachability from normal, prompt access. Storage, roof geometry, ceiling access, other MEP, and the maintenance route can turn a coordinated symbol into a redline.
Ladder to the RTU disconnect
Walk the route from the normal point of entry to the operating handle. If a ladder, obstacle move, climb, or destructive removal is required, flag it before the equipment location is frozen. Do not defer required access to inspection-day improvisation.
Source: Sparky accessible · tool: access screen · IMC 306: equipment access.
What to send
Roof/mechanical photos of the path to the disconnect (safe access only), and whether a ladder or stored items are in the way.
If the disconnect needs a ladder
Send the path photo. Masterbuild will say whether Article 100 even calls this readily accessible — or the location has to move before the RTU is set.
Send Project Background+1 (786) 398-6940 · osmany.portal@masterbuildconsulting.com
Masterbuild provides engineering services under a written scope. Nothing on this page is project-specific engineering advice, a code interpretation for your project, or a representation about permit approval. Sparky Edition uses the 2026 NEC as model-code education. Confirm the adopted edition. Field observations do not establish electrical safety; only qualified personnel using required safe-work procedures should access electrical equipment.