Jeffery Please consider your mechanical connections and the duty cycle of this Adaptation. I have an air conditioned cruiser I keep on Lake Erie. It has two L5-30 125 V marine power feeds that come to a power distribution panel. Current ( and voltage) is constantly monitored on analog meters (two per feed, -one Volts - one Amps.) The one feed that runs only the Air Conditioner, averages 9 Amps and the other house circuit, which has a battery charger and refrigerater on it, average 5 AMPs so I thought One 30A Cable could supply the boat. ( got tired of the mess of two cables draped over the bow and decks - spider habitat! ) After a couple seasons, I made a splitter out of 10 Ga stranded copper wire using heavy set screw terminal lugs for the split connectors. I ran one 30 Amp cable 30 feet to the splitter. and then let the 20 inch splitter, split the feeds. I used all top quality 'Hubbell" marine connectors for the terminal receptical(s) & outlet(S) on the single feed cable and the splitter. Just this last season I left Air conditioner running for about two of the hottest weeks in September ( freakish -Indian summer). When I went to cast off the lines for a Fall trip to the Islands, the terminal connections on each end of the single feed cable failed due to heat. Un-twististing the twist lock at the remote receptical end was tough, then the Ground and Hot blades pulled out of the plug end at the dock outlet. I had to switch off the dock breaker and extract the blade components using needle nose pliers. My Point is the 30 Amp feed cable (the oldest component) perhaps had some vibration, or corrosion, compromised mechanical connections. Which over time (2 weeks) created enough heat to compromise ( melt) the quality parts. All my parts were rated at 30 amps, and I knew my usage was less than 19 Amps! ( If I was not in a hurry to take the splitter with me, the parts may have cooled and re-set (solidified) rather than than pulling apart. But it was truly an education in real world failure modes of decently rated parts. If you are adapting down to a 15- 20 amp plug, you will still need to be EVER mindful of the physical condition, and operating temperatures of any mechanical connections you make. Sincerely Larry Truthan Digest Subscriber