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Friday, April 28, 2023
Question:
Hello CQD. Can a 3-phase service be added/installed on a dwelling unit to supply an HVAC load? This service would be in addition to the 1-phase 120/240V service already installed. Thanks, Jason Brown.
A
Answer:
Hello Jason, interesting question. Yes, this would be permitted by the
NEC®. Section 230.2(D) permits additional services with “different characteristics”. These different characteristics can be
voltage, frequencies, phases, uses, or rate schedules. Even though this is permitted by the
NEC® it is advisable to check with the local Utility and AHJ as there may be limitations on availability or local rules prohibiting such installations.