Quick Advice on Electrical Setup

[PigPen]

We're finally putting our electric in. Our needs are extremely low compared to most people, so our system is very simple.

Our two power sources will be shore and a generator. There will be one cord that is either plugged in to the generator or to the shore pedestal.

The cord will connect to a 3 stage converter charger and an ac/dc distribution center (that's all in one unit).

No neutral ground bonding on the bus.

We'll have a small bank of 2 6V batteries, wired in series.

We may add an inverter in, but it would be small and for one job only - charging a computer when I absolutely have to work and there is no other way to charge it. I don't expect this to be often when boondocking.

The run between the batteries under the bus to the converter & load center inside will only be a couple of feet. The batteries will only be used for a fan, a water pump, maybe lights (we've been using ones with their own batteries and are happy with them so far), and the inverter in rare situations.

With that in mind, three questions:

How big does the cable for the two batteries need to be (for connecting them and connecting them to the converter)?

Is 10AWG correct for 30amp ac service?

The generator I'm looking at is described as having "grounded outlets" - this is what I want, correct?

[PNW_Steve]

You will want the neutral bonded to ground in the generator.

There should be ONE point in the system where neutral and ground are bonded. When you plug into shore power that point will be provided. When you plug into the generator you will need to provide it.

#10 is correct for 30 Amp service. For longer runs using a larger wire size is desirable to minimize voltage drop.

Here is a good explanation of neutral ground bonding : Generator Ground-Neutral Bonding | No~Shock~Zone

[PigPen]

I understand the concept of neutral ground bonding, but I was under the impression that some generators provide this and others do not and was curious if that phrase meant it was or wasn’t.

If that’s not the case, I was going to make one of those modified plugs to put in the open one.

Edit: Read that link and it does explain that some generators have the bond. I guess that question really isn’t that important now though because I can make it work either way.

[PNW_Steve]

The wording sounds to me like it is describing receptacles that have a ground connection. It is not entirely clear. I would check with the generator manufacturer.

Here is a page that describes using a multimeter to check bonding : Universal Generator Switch for Two Types of Generators and What You Need to Know - EZ Generator Switch

[PigPen]

Yea, you must be right. It seems like almost all or all inverter generators have an unbonded ground.

Here's another question that I've come across now that I'm actually amassing the materials...

The AC wires that I'll be running will be inside cabinets but not inside the actual walls. I was thinking of using the flexible metal conduit stuff for all my runs (3) - anyone know of a reason I shouldn't do that?

I'm going to go back and reread the electrical thread one more time before actually starting to install.

[ThunderstruckStudios]

For sizing the wires between batteries and between batteries/inverter....how big is your inverter in Watts?

Say it's 1,000 Watts. That's 1,000 W / 12 V = 83.3 A max discharge current from the battery. Using a chart like this one and assuming your connecting wires are less than 10 ft (keeping them short is good), you should use 4 AWG wire.

Of course, adjust the numbers if you have a different sized inverter.

[john61ct]

Blue Sea Circuit Wizard app is better than any chart. Plus educates you as to all the factors involved, post Qs back here.

[2martins]

Originally Posted by PNW_Steve

You will want the neutral bonded to ground in the generator.

There should be ONE point in the system where neutral and ground are bonded. When you plug into shore power that point will be provided. When you plug into the generator you will need to provide it.

#10 is correct for 30 Amp service. For longer runs using a larger wire size is desirable to minimize voltage drop.

Here is a good explanation of neutral ground bonding : Generator Ground-Neutral Bonding | No~Shock~Zone

All this is over my head. I have convinced my son busplusplus to do AT LEAST 30 amp service equivalent and go ahead and set our system so that we could use 30 amp shore power if desired or to make it more appealing to sell. He is near LA and there is place that sells deep cycle batteries but hasn't figured out how many to buy to be able to power the equivalent of 30 amp shore power. He figures that the generator would need to be 3600 amps I think it was. If I only want to run the generator 4 hours a day to recharge the batteries, how many deep cycle (I think like golf cart ones) would I need?