50 amps dockside no longer enough...

[Zydeco IV]

So I've recently added another 16k btu unit to cool my galley and forward cabin in my 53 MY. It gets very warm down here early in the year and stays that way thru Oct. It puts me right at 50 amps consuming on typical summer days. I've got a 16.5 kw northern lights that handles all my need beautifully, but dockside I've got to constantly watch my wife with the hair dryer, electric stove, toaster, etc... not condusive to relaxed atmosphere when we're tied up.

Any thoughts on my options? Should I look to re-wire for more capacity?

[Pascal]

I have a similar situation when I recharge the inverter bank coming back to the dock, I have to reduce the charge rate down to 5amps otherwise breakers start poping when we have all the AC running.

I've thought about adding a 30 amp shoreline with an auxiliary panel to power the charger (or an extra air con in your case)... pretty simple... will eventually get to it...

not much you can upgrade to from your 50/240-120... most marinas have 30amp shorepower on the same pedestal, but finding a second 50amp woudl be harder. 30amp hardware is also much cheaper....

[Genesis]

BIG Yacht connections are 100A. I've seen FEW marinas with those plugs tho.......

Realize that a 30/125V is actually about 1/4 of the capacity in terms of watts as a 50/250.

[Pascal]

yes it is, but if all you need is an extra 30amp for charging or 15amp for an extra AC, then 30amp will do it for cheap. there are a couple of boats on my dock with twin 50amps, that's an option but I many marinas dont' have twin 50amps at each slip...

4 AC on the 53 is marginal in the tropics with the heat from the engine rooms. Mine had a 5th at some point, as evidenced by some cabinetry work in the galley and marks from an extra shelf for the condensing units in the ER.

I'm actually thinking about using a smaller unit for the VIP SR and the full 16k for the galley and fwd SR.

[Zydeco IV]

You know I think I could get by with with a total of 75 amps, possibly 70. So would it be difficult to add a 30 / 125 line and panel to the boat and dedicate that new A/C and say my water heater or something within it's limit to it? Or should I go all the way with 50/240?

Regarding marina shore power, many but certainly not all of the places I'm pulling into now have twin 50/240's on a single post. Am I wrong to assume that with more boats with larger power needs coming on the market that marinas down here will be forced to upgrade over time?

Hmmm, on second thought, maybe I should stick with Pascal's insight about the 30amp. It would work fine now AND later.

[SKYCHENEY]

I have twin 50/240 inlets and I am able to use them at most of the newer marinas. It is great to just put the A/C's on one 50 and the rest of the house loads on the other one. That way I can just "set it and forget it". If I am at a dock with only one 50amp then I have to watch the loads as you do now.

[Nonchalant1]

If yours is like mine, you probably have dual 120/50 inlets that you never use, because 120/50 is very uncommon and plugs are different. You could convert one of those into an inlet that can be switched to run only the new Air Conditioner. With a single switch, you could select the normal circuit for that A/C (like when you're on genny), or the separate 50 amp inlet (dockside). This would not be that difficult or complicated to do. A 16KW CruiseAire will run on 120/30 power so you could just get an adapter to put 120/30 into your switched 120/50 inlet.

If for some strange reason you ever need a 120/50 inlet, just use the other side.

Doug Shuman