I’m considering switching from 2 x 30A to a single 50. The boat currently has two 30A isolation transformers. If I switch to 50A I either have to upgrade the transformers to a single 240@50A or just go straight to the panel. By the schematics, the neutral and grounds are not bonded. Is there a compelling reason to spend &2k + on an isolation transformer? The conversion becomes much easier and less expensive without it. The marine electricians take on it seems to be that it’s a nice thing to have, but if the neutrals and grounds are not bonded, you shouldn’t need it.
Your boat is fairly new so wiring shouldn't be played with. I would not spend the money on isolation transformers, not really needed. If you have neutral issues, without the iso Trans, you will trip the newer docks GFCI breakers. The iso is a very poor bandaid for this problem, just find the faulty neutral connection and move on. No ISO needed if wired correctly. Do a search here, we've discussed this earlier this year.
N and G should never be bonded on the boat except at the generator and at the inverter when in use. This is why it s critical to use a marine inverter which has the circuitry and relays to bond N to G only when in inverter mode iso transformers are nice to have but most boats under 50/60 don’t have them. As long as you don’t have an appliance which has N and G tied inside, you don’t really need them. personally I d rather have 50Amp and no transformer than 30s with transformer.
Thanks guys. There aren’t many 120V appliances. I’ll check them at the panel and make sure they have separate neutrals and grounds. I did replace the cable ends and that seems to have helped a lot. Also making a point to add for two 30’s at marinas so I can avoid using the splitter.
Most appliances on your boat should be marine anyway. Problem occur on bigger boats with home fridges, freezers, washers etc although in think most of recent appliances don’t bond N to G. When my marina rebuilt after Irma and installed GFIs, quite a few boats had issues. All my appliances were fairly new and were ok. Non marine inverters are usually the culprit.
I really think that you're "over thinking" this. Eliminate the ISO trans if they are really there, switch to 50amp and you're done. If anything else pops up ( neutrals) deal with it then. And keep the cable master.
That’s the plan. There are two cable masters right now. I can delete one of them but 50ft of 50A cord may not fit in the existing tub. I’ll address that when the time comes. Thanks for the suggestions guys. Another project added to the winter list.
Uneventful to Amelia Island. The power situation seems to have at least stabilized. Replaced both cable ends and requesting 2 x 30 when I book a slip. Last 2 nights have had 2 x 30 and no hot plugs or cables. Going to replace both ends on the splitter just in case. Probably be anchoring out the next night or 2. Next marina stay will probably be Hilton head for a couple night to visit friends.
