I'm planning on adding a 30 amp generator input with a breaker interlock to my house but I've ran into a problem. Seems my 1976 Gould breaker box doesn't have a separate neutral bar. the plug is a 4 prong with two hot, a neutral and a ground . Any ideas would be helpful.
Thanks

Where are all your neutrals connected in the main panel now?  Just connect it there.  (assuming there is an available spot for your new ground and neutral wires).  Neutral and ground bus are bonded in main panels.

Probably a main panel where all neutrals and grounds go to the same bar.

it is. All of the grounds and neutrals are on the same bar.

If wired at the main box or safety switch, the common and ground are brought together there.
If in a subpanel, they must be separated (isolated).  This prevents the ground loop.
If needed you could a separate ground for the gen connector.  It could be carried to the service ground as its own line.  
Size matters :)

Connect both the ground and the neutral to the single bar in the main breaker panel.  That's what it's there for.

Thanks , I'll look into going into the ground rod its just on the other side of the wall

I was reading that would be bad ju-ju . honestly I have worked mostly with low voltage DC and 110 wiring with one simple 220 wiring job.

Is your generator putting out 110 or 220?

The plug I would be using is labeled both 110 and 220. It's your standard 30 amp 4 prong generator plug.

Ok what voltage does your generator put out?  

I can slap any plug on any component I want to if I’m feeling dumb.

Is your generator a 110v or 220v generator?  

A 30 amp generator is going to be 110v 98% of the time.

Do you have the generator yet?
Reason I ask is every generator I've seen with a 30amp 208/220v outlet required a 3 prong plug not a 4 prong.

Main panels do not normally have separate ground and neutral bars.

Sub-panels are required to have them.

It is not all that hard to add a separate bar for grounds.

You do need taped and threaded holes for the electrical connection to the box from the ground bar.

Yes I've got the generator and its a 240V 30A with 4 prongs

Thanks .  I had my boxes and wires crossed up on that one.  I'm going to be adding a sub panel so now I'm looking to at will there be any issues with using the same ground rod as the main box
I really don't think that's going to be an issue

Sub-panels do not require a new ground rod as long as they
are in the same building as the main panel they are fed from.

You do have to run 4 wires from a main to a sub.
Hot, Hot, Neutral, Ground.

In the sub grounds and neutrals must be separated.

Most panels are set up so that you can disconnect the ground to
panel box connection by removing a single screw.
You then install a ground bar and connect it to the panel box
using a machine threaded fastener.
NO SELF TAPPING SCREWS HERE.

You probably should find someone with a little more experience to guide you.

This is all pretty standard stuff.

Errors here can range from "oops" to fires and electrocution hazards.


You are NOT required to have a 'main' switch in a sub panel.
The panel feeding it will have a breaker to protect the feed lines.

The advantage of using a main is that you can turn it off and know that the only
thing in the panel that is hot are the feed lines into the main breaker.

It's bad ju-ju IF neutral and ground are bonded at the generator as well and the ground conductor connects the two together. This would allow the ground to become a current carrying conductor.

To do this right you need to be sure the neutral of the generator is not bonded to ground.

The catch is, then when you go to use the generator stand-alone they aren't bonded when they should be.

The best solution I've seen (not sure if it's to code or not) is to have a separate ground rod that the generator ground is connected to and the ground/neutral of the generator are bonded with no ground conductor back to the panel.

An easy way to do this is to have a generator inlet plug on the outside of your house with the L1/L2/N going to the panel and the G going to a ground rod. This way when your twist lock cord is connected to the generator inlet the generator is grounded through the ground rod, with no other conductive path.

Grounding of a generator that will see both portable use and structure-connected use is not a simple affair.

ETA, I should quantify "bad ju-ju" in this case. When you double bond a backup generator setup it makes it so neutral current will run on both ground and the neutral between the 2 bonds (a little bit goes to each).  This is bad in a normal bonding situation bc grounded conductors can often be exposed metal items in the house. We don't want electricity on those. However, in this particular situation the ground conductors found between the 2 bonds should all be insulated or enclosed in rated enclosures. Parallel neutrals can also mess with gfci's. In this case, neither of those concerns are really all that concerning, especially when put into perspective with the following.

There is NO 100% perfect way if doing this unless your generator will be used as ONLY one or the other (portable with device directly connected or interconnected through a panel). The risks if creating a parallel neutral by leaving the G-N bond at the generator are far lower than the risks of removing that bind then using the generator as a portable (no bonded ground path). I will not advise you what to do, but I have left my generators bonded.

The ground rod thing mentiome6above has it's own issues as well...



Haven't been around many generators have you?

Not if your talking about these little toys we use to power our houses, just the 4 small ones I've owned, 3 portables that had 3 prong plugs & now 1 Whole house hard wired unit.
But I operated a 1440MW powerplant for a few years!

As I understand it:

Neutral should be floating for connection to the house.

You can use a floating neutral generator stand-alone but should drive a ground rod and attach this to the ground lug that's bonded to the frame.

You wont have a separate ground/neutral on your main breaker panel. It is required to remove the ground screw to separate the ground/neutral if using a sub-panel.

That is why you can't buy main panels that come with ground lugs.  Yet they are a couple of rows over and in eye-sight from the panels you just bought. If you look at the row a bit more.

DIASCLAIMER: I AM NOT A ELECTRICIATION.

Where you attach the grund rood is the Q. Easy to answer if you already the answer.

Whatever drugs you took at about 8 PM EST last night was some good stuff!

220V

240/120V since 1967.