Actually, the 240V (120-0-120) is single phase. Both sides are on the same phase in normal installations. Re-wiring your boat for two separate 120V, 30A circuits (if feasible) gives you much more flexibility. If you only find one 30A circuit at a marina, you can use a "30A to double 30A" splitter. It won't give you any more than a total of 30A capability, but with careful load management, you can do okay. 30A is enough to run a 16k BTU A/C and one microwave/ toaster/stove/water heater plus the battery charger without trouble. That's what I had on my 28' Carver until I added a second 30A circuit. The genset was still only 3 kW and I rigged up a transfer relay so that both 30A circuits were paralleled. D C (Mac) Macdonald m/v Another Adventure (Carver 355AC) AGLCA #217 USPS USCGAux ----Original Message Follows---- From: Skipper Bob <SkipperBob@att.net> To: great-loop@lists.samurai.com Subject: GL: Reverse Y Adapter Date: Wed, 11 Aug 2004 08:11:08 -0400 Jim Alexander, The Marco 167RY may not be much use to you. I had one and it worked great when we were in a marina with only 30 amp outlets, and they had two phase power on the dock. In other words 2 phase 240 V power must be on the dock to enable the 167RY Reverse Y Adapter to work. Many small marinas with only 125V 30 amp outlets do not have two phase power on the dock. They may have two phase power in the marina and in fact one side of the dock may be one phase and the other side of the dock (or another dock) may be the other phase. But, unless the marina is wired with 240V two phase power at each power stand, the Marco 167RY is useless ($400 thrown down the drain). When we did the Great Circle Route we discovered that most of the marinas in the inland waters where we needed the adapter did not have 240V 2 phase power on the dock. This rendered the adapter useless. Instead, we finally solved the problem by rewiring our boat to two 30A single phase inputs and eliminated all 240 V requirements on the boat. Then we could use two 30 Amp shore cords from the same phase 30 Amp outlet. This made our electrical requirements much simpler in the smaller marinas of the canals and inland waterways. By the way, the cost of rewiring our boat was a lot less than one Marco 167RY adapter. If you want more specific information on rewiring your boat from two phase 240V 50Amp service to one phase 120V 30Amp service contact me directly off line. Bob Skipper Bob Publications Http:\\SkipperBob.home.att.net