CONDUCTORS · REFERENCE GUIDE
Bare and mineral-insulated conductor ampacity
Reference guide to bare and mineral-insulated conductor ampacity: the checks to work through and when to verify against the NEC and the manufacturer's data.
US (NEC) only · NFPA 70 / NEC — locally adopted editionDefaults are US values. Verify the locally adopted NEC edition and project data.Official reference ↗
REFERENCE GUIDE
Before starting
- Bare and mineral-insulated systems cannot share generic insulation-table defaults.
- Use the exact conductor/cable manufacturer ratings and adopted-code method.
- Account for enclosure, spacing, exposure and termination conditions.
This is a reference guide, not a sizing calculator or installation approval.
Method & assumptions
Reference workflow — project-specific verified data required
This is a reference guide, not a sizing calculator or installation approval.
Results do not check every aspect of an electrical installation. The calculators follow US (NEC) practice only; a regional preset changes defaults such as voltage and units, and no result certifies NEC compliance.
Sources and validation →Estimating and invoicing tool
Ampxa is developing an estimating and invoicing application for electrical contractors. The list below receives notice when it opens.