My input, for what it's worth....
.... As far as I know I want to have my generator hooked to a transfer switch (automatic vs manual? I would assume automatic is better?) with one line running to the inverter and one to the main panel.
I would suggest that you use the "idiot-proof" method of hooking the generator to the rig. It's one we used on our previous RV and will use on this one. We also plug the food cart directly into a power outlet on a pole or on the generator. Your power cord is wired directly to the power panel/breaker panel "main" breaker. To run from "shore" power (power pole) you plug into the power outlet attached to the pole. To run off the generator you plug the same cord into the generator outlet rather than the power pole outlet. Auto transfer switches fail and when they do, have a tendency to cause major problems. It also take the really big problem (YOU) out of the equation. If you accidentally back fed into a down system, you could possibly electrocute someone. This is why many grid-tie solar systems have to have insurance when they hook into the power grid. I've heard of RVers who have had it happen. We were in a campground when an RVer's auto transferred generator went nuts and back fed into the electrical system. Fried half the park. Luckily it didn't affect us.
As far as inverter/charger goes, anything I should look out for? Those run to the two deep cycle 6 volts. I was hoping to have a set up where when not hooked up to shore power the generator would automatically kick on when the batteries were getting low. Is this the right approach?
For starters, you need a "smart charger" on your battery bank. We will be powering our RV off of a PD4045
. We will be running two 12vDC Deep cycle marine batteries. I don't know what kind of equipment you are running or what you are running off of the two 6vDC batteries (must wire to create a single 12vBattery... gives you 125 Amp?). Unless you are only powering a 12vDC water pump, you will need a bigger battery bank.
You need to learn a little. Try reading up on the batteries. Phred's Poop Sheets
are best. I would suggest you read "Batteries & Other Electrical Stuff" and "Electric surge and High/Low Voltage". It's all written from an RVer's point of view so there are things that won't apply to you. But much of it will. Like an RV is a house on wheels, a mobile food cart is a restaurant on wheels. Lots of similarities. YOU WILL BE SUSCEPTIBLE TO POWER SURGES AND OTHER INCORRECTLY WIRED VENDORS!
I will be having an electrician do it all but just wanted to find out what products and set up have worked best for everyone. I'm only doing shaved ice so my power requirements aren't too high. Shaver, freezer, LED lights, A/C sometimes (in San Diego so not always needed), Audio/Video sometimes, instant hot water heater.
Instant hot water should be LP.
Look, IF this was my cart this is what I would do...
>Manual hookup to the genset/ power pole.
>30 amp panel box box (I would install the PD4045
to charge the batteries for the water pump and DC to AC inverter for the AC lights)... 30 amp because it's more "small event friendly". The only events we are interested in are small ones and many of them impose limits on our power usage. Small cart = small events. Big events may have similar situation.
>LP water heater
>12vDC water pump powered from batteries. Two 6 volt would be my minimum. I would actually buy two 12v Deep Cycle Marine batteries... the last one we bought was for the Class C and we fulltimed from 2006 when the single deep cycle marine battery was bought from Wal-mart thru December of 2011... my daughter stayed in the RV and is still on the same house battery... and the Class C has an old dumb converter/charger). While the generator is running, the batteries are simply passing power. They should not drain down. The smart charger will keep the batteries topped off when you are running the generator or plugged into shore power.
>DC to AC Inverter (like a 600 to 800 watt one... cheap) to power the AC lights (got light when no genset/shore power... good when traveling on the road). AC lights are about 1/2 the price of DC lights. It will also provide clean power if you are running an AC sound system. Generator power will vary unless you have a power "conditioner" inline. The Onan on the Class C we used to live in was so bad I could not run my desktop computer off of it. The DC to AC Inverter will allow you to run AC stuff off the batteries. What you can power depends on the size of the inverter and the size of your bank. I suggest multiple "dedicated" inverters rather than a single big inverter... in case the inverter dies in the middle of an event, you can switch it out with another inverter you aren't using. Inverters run directly off 12vDC system. Place all inverters very near battery bank but not inside the battery box (battery gases will eat the insides out of any electronic gizmo). Power cords from inverter to appliance can be long runs (I would stay under 40 ft runs... shorter is better than longer and use nothing less than 12 gauge wire)
>INSTALL IT MY SELF. You need to be able to make repairs while at an event on a weekend. Otherwise you are at the mercy of an electrician who does not understand mobile electrical systems. Even if you get an electrician to install it. You need to know enough in case they do something wrong. Too many electricians don't even know that the ground on a mobile unit is the frame... power pole or generator, it's still the frame.
That is what I personally would do. There is no one way to do anything. Someone else would do things differently.
<message edited by lornaschinske on Fri, 06/8/12 2:47 PM>