MEP Engineering · Engineering Glossary
An emergency or standby generator is a diesel or natural gas fueled engine-generator set that provides backup electrical power when the normal utility supply fails. Life-safety systems — emergency lighting, fire alarm, elevators, critical equipment — require backup power in many occupancies under the NEC and IBC.
The NEC Article 700 governs emergency systems (required by code for life safety), Article 701 covers legally required standby systems, and Article 702 covers optional standby systems. The electrical engineer sizes the generator based on the connected emergency and standby loads, designs the automatic transfer switch (ATS) that switches from utility to generator power, and coordinates the fuel supply system. Structural engineers must design the generator pad and anchorage, and acoustical considerations often drive placement and enclosure design. Generators must be tested regularly under load per NFPA 110. For healthcare, data center, and mission-critical facilities, N+1 generator redundancy and paralleling switchgear are standard design practice. Apex Grid engineers generator systems across all commercial and government facility types.
Apex Grid Engineering maintains this glossary as a resource for architects, contractors, developers, and property owners who encounter unfamiliar engineering terminology on their projects.
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