Shorepower: 480 VS 100amp three phase, or 100 single

Background. Lazzara 116 with 2005 vintage Atlas ShorPower system. Whatever you throw at it… single or three phase, 208,240,480, 50 or 60hz, it will output 240v 60hz

At our home dock we have 480v so we never have an issue. Never tripped a breaker, no matter what we use.

now when we travel and dock, it s always a PITA. Very few marinas have 480 so we usually have to connect both cords instead of one. Since we are usually on the hook, I don’t have to deal with shore power very often. But when I have to… we keep tripping at the pedestal. The (aging) 100 amp breakers are very hot.

today we are at ocean reef. No 480v, just a pair of 100 amp three phase. I have both cords plugged in, the Atlas shows both cords are online, yet we keep tripping one of the pedestal breaker.

Since we rarely have to deal with 208/100, I m not sure whether it’s a dock issue or just the fact that it just can’t deliver what 480 can.

obviously with a full house, in summer, shutting down one of the chiller isn’t an option… nor is turning off the hot tub or ordering take out food

So…. Is two 208/100 really much less than a single 480/100? Are we just power hogs driving the planet into oblivion with rising sea levels refusing to play the breaker game and shutting down some loads?

what do boats in our size range typically use for shore power ?

Yeah I am aware of possible burned outlets and aging breakers. I m staying on gen tonight, not getting up every two hours to reset the breakers ….

jusy trying to figure out whether 2 three phase 100 is as good as a single 480

I had the technician from Atlas on board last year to check the system and maintain what had been ignored for years incl replacing a number of contactors and cooling fans.

he also confirmed that the system is pretty much automatic, so no configuring which phases are used.

problem is that we only have a single three phase at our home dock, plus the 480, so we can’t test the system using two three phase. That said, here at Ocean Reef, both indicator lights show both cords active and pulling power

So two 208s should provide more amps than a single 480? Isn’t 480 three phase?

our gens at 45kw and never trip (never had to run both) so getting 48kw out of the 480 would be enough as well

We have two power cords, both originally with 5 pins 208 connectors. When we brought the boat to our home slip, I replaced one of the connectors with a 4 pin 480v and that’s the cord we use at home

i also bought a 480v 4 pin female and 6’ of cord and made an adapter to connect the 480 cord to a 208 three phase outlet so we can use both cords when 480v isn’t available.

with this set up, I have both cords activated (green LED on each at the Atlas selection box), but just not enough power as trips one dockside breaker

yeah, that’s what i m wondering. With both 3 phase cords active, I have 214 v coming in the Atlas with 0 load as we re on gen.