IMC · 2021 International Mechanical Code

§303.1 · Identification

Effective in IMC 2021 · IMC 2024 SE Wisconsin · IMC 2024 NW Indiana.

Plain-English explainer

303.1 requires a permanent placard at the main shutoff or service disconnect identifying a new mechanical system. Trussmark treats this as the placement rule for the system-id label the field crew puts on the equipment after the install.

Why inspectors flag this

Most jurisdictions fail a final if the system-id placard is missing, even on a clean rough-in — surfacing this on the draft makes it visible before the inspector walks the site.

As quoted in the code: A permanent placard at the main shutoff or service disconnect identifies a new mechanical system.

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