MEP Engineering · Engineering Glossary
The National Electrical Code (NEC), formally known as NFPA 70, is the standard for safe electrical installation in the United States. It is adopted by most states and municipalities as the governing code for electrical design, wiring methods, overcurrent protection, and grounding.
The NEC covers everything from conductor ampacity and conduit fill to panel board ratings, grounding electrode systems, and special occupancy requirements. Articles in the NEC address specific conditions: Article 220 covers load calculations, Article 230 covers services, Article 250 covers grounding, and Articles 500–590 cover hazardous locations and special systems. Electrical engineers use the NEC to size service entrances, select overcurrent protection, design distribution equipment, and verify code compliance for lighting, power, and emergency systems. Like the IBC, the NEC is updated every three years and states may adopt different editions — verifying the adopted NEC edition is standard Apex Grid practice.
Apex Grid Engineering maintains this glossary as a resource for architects, contractors, developers, and property owners who encounter unfamiliar engineering terminology on their projects.
View All Engineering TermsApex Grid's licensed PEs provide mep engineering services across multiple jurisdictions — with fast quote turnaround and permit-ready documents.
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