Solar PV Inverter Output Conductor Sizing: 7.6 kW 240V Continuous Output
Calculate minimum conductor size and overcurrent protection for a 7.6 kW 240V grid-tied solar inverter under NEC 690.8 continuous duty rules.
Calculated strictly in accordance with NEC Article 690.8(A)(3) & 690.8(B).
On This Page
Need custom loads or multi-circuit runs?
Use the full Residential Electrical Service Load Calculator for deratings and printable worksheets.
Launch Full InstrumentGiven Scenario Parameters
Interactive Calculator (Pre-filled)
Adjust inputs to evaluate variations of this NEC code scenario.
Interactive Electric Load Calculator
Pre-loaded with NEC 220.51 & 424.3(B) parameters
Nameplate wattage of the heating unit or load
Line-to-line or line-to-neutral
NEC 424.3(B) mandates that fixed electric space heating equipment branch circuits must be sized at 125% of the total load current.
Step-by-Step Solution
Formal engineering derivation citing applicable National Electrical Code articles.
Calculate maximum continuous inverter output current: 7,600 W / 240 V = 31.67 Amperes.
Per NEC 690.8(B), multiply maximum inverter output current by 125% for continuous duty: 31.67 A * 1.25 = 39.58 Amperes.
Select conductor from Table 310.16 at 75°C: 8 AWG copper (rated 50A) or 8 AWG THHN.
Select overcurrent protective device: 40 Ampere double-pole circuit breaker.