12kw generator to 30amp panel wiring

[Sna]

I’m prepping to install a new to me 12kw generator. The boat’s been generator free for a couple of years since the prior owner had the previous 12kw genny removed. I just replaced the main AC electrical wires which were pretty thick at AWG 3 gauge because they had been spliced in a few areas.

- What’s the best way to connect this very thick wire to the source selector switch on my 30 (120v) amp panel. It’s a new panel (Blue Sea) and the specs for the switch call for a much smaller wire size. I could set up a single main breaker panel for just the genset and then run a smaller cable to the panel selector switch but don’t know if that’s a good idea.

- The more general general question is why do boats have generators that are 10-12kw (up to 100 amps at 120v) when the panels are rated for far less amperage? I’ve already got the Northern Lights generator to put in based on a great Craigslist deal.

 

[tiltrider1]

A 12kw genset is capable of providing 50a of 220v or 100a 125v. This gives you enough power to run the boats Air conditioning, washer/dryer and/or electric stove. Usually they are set up with a higher capacity switch and two 50a circuit breakers.

Since you are simply running a single 30a 125v circuit you need neither a generator that large nor do you need wiring that big.

You are probably better off installing a 3kw genset.

You failed to give some critical data which leads me to believe you need some professional electrical help before you get into some trouble.


Just my opinion.