50-amp inlet (14-50 / CS6365)
Large portable generators above the 7,200 W ceiling of a 30 A connection use a 50-amp, 120/240 V connector — either a straight-blade 14-50R (the “RV/range” outlet) or a CS6365 twist-lock — carrying up to 12,000 watts into a 50 A generator inlet.
If a generator’s running watts exceed 7,200, a 30 A cord physically cannot carry its full output at 240 V; the 50 A path (14-50 or CS6365 on the generator, a 50 A inlet box on the house) is what unlocks it.
CS6365 twist-locks are the more robust choice for backup-power duty; 14-50 outlets are common because they match RV and range hardware. Either way the house-side inlet, wiring, and breaker must all be rated 50 A and installed by an electrician.