Which 20kw whole house generator would you recommend and why

[pclausen]

Ground rod at generator is optional. I have seen it engineered and passed with a ground rod, and without. You are required to have both a neutral and ground from the generator to the transfer switch.

I have a #6 ground and #4 neutral between generator and transfer switch. I have #6 ground from generator to optional ground rod.

So I do not need to add a #6 ground from generator ground to house ground rod, correct?

The non transfered panel can have neutrals and grounds on the same bar, with a main bonding jumper, fed from the meter with SEU cable (2 hots and a ground).

And this is allowed even though I have moved 14 breakers from this panel to the sub-panel behind the transfer switch?

The transferred panel is now a sub-panel, neutrals and grounds should be separate, no main bonding jumper, fed from the transfer switch with SER cable (2 hots, neutral, and ground).

That's what I have now. The ground is not part of the SER cable, but a bare #6 between the transfer switch ground bar and the newly added ground bar in the sub-panel.

The transfer switch (which needs to be service entrance rated in this case), is now the main breaker for the transfered panel, and should have a main bonding jumper, fed from the meter base with SEU cable.

My transfer switch is SE rated and has the main bonding jumper intact. The only thing missing from the service panel, is a #6 ground to the house grounding rod. It is currently indirectly connected to the house grounding rod via the #6 between it and the sub-panel, which in turn is connected to the house grounding rod.

 

[podagrower]

I have a #6 ground and #4 neutral between generator and transfer switch. I have #6 ground from generator to optional ground rod.

So I do not need to add a #6 ground from generator ground to house ground rod, correct?

Correct, but it would not hurt anything either.

And this is allowed even though I have moved 14 breakers from this panel to the sub-panel behind the transfer switch?

Correct, you still have 2 main disconnects (transfer switch, and non transfered panel), just like you did before you added the transfer switch.

That's what I have now. The ground is not part of the SER cable, but a bare #6 between the transfer switch ground bar and the newly added ground bar in the sub-panel.

This isn't quite right. You have a #6 bare ground, which is the correct size, but you are using the 2/0 bare conductor from the SEU cable as your neutral, it should be SER cable, which includes 2 hots, a neutral, and a ground. What you have will work, but it's not right.

My transfer switch is SE rated and has the main bonding jumper intact. The only thing missing from the service panel, is a #6 ground to the house grounding rod. It is currently indirectly connected to the house grounding rod via the #6 between it and the sub-panel, which in turn is connected to the house grounding rod.

Your grounding is fine, since both the non transfered panel, and the transfer switch are connected to the grounding electrode conductor in the meter base. (This connection may be made in the meter base, or the main panel depending on local practices and power company requirements).

 

[pclausen]

Thanks. Appreciate the feedback!

So here's a quick sketch of my neutrals and grounds. The only thing I was not able to do was to tie the transfer switch ground bar directly to the house grounding rod since it is buried underneath the back-fill with a 6x6 on top of it. I would estimate it is connected maybe 6" above it, to one of the panel ground wires. This is shown in the red circle below.

 

[Rock knocker]

I am so confused, your diagram shows bonding at the meter, transfer and panel 2?

 

[grsthegreat]

250.35..

that says nothing about NOT using a ground rod at a generator.

my 2001 book is in my work van, but read 250.30 exception 2 (from 2008 code...im not sure if its been renumbered in 2011...ill have to look. it talks about allowing multiple ground bonds AS LONG as a parallel path for grounding is not established. A hard wire connecting all ground rods prevents a parallel path.

I have made ground planes before with 8-10 ground rods for use in highrises and communication equipment. all were tied together and all were 100% legal.

 

[podagrower]

Thanks. Appreciate the feedback!

So here's a quick sketch of my neutrals and grounds. The only thing I was not able to do was to tie the transfer switch ground bar directly to the house grounding rod since it is buried underneath the back-fill with a 6x6 on top of it. I would estimate it is connected maybe 6" above it, to one of the panel ground wires. This is shown in the red circle below.

The green wires you drew from your panels to the rod are actually connected to the rod thru the meter base, right? That's how the pictures from earlier look. You don't need a ground wire to the rod from the panels or transfer switch.

I am so confused, your diagram shows bonding at the meter, transfer and panel 2?

The meter base bond shown is the connection to the grounding electrode conductor (wire that goes to ground rod), not a bonding jumper. Bonding jumper at transfer switch and panel 2 (both of which are main disconnects at this time) is correct.

 

[pclausen]

The green wires you drew from your panels to the rod are actually connected to the rod thru the meter base, right? That's how the pictures from earlier look. You don't need a ground wire to the rod from the panels or transfer switch.

The existing installation has a total of 3 #6 ground wires, each individually run to the house grounding rod. One from each panel, and one from the meter base.

The picture below shows the 3 #6 wires going down to the underground grounding rod. The telco NID (grey plastic box) is tapped into the meter base #6 wire.

The technical manual that came with the transfer switch shows 3 connections to the transfer switch ground bar as per the sketch I made.

 

[podagrower]

The existing installation has a total of 3 #6 ground wires, each individually run to the house grounding rod. One from each panel, and one from the meter base.

The picture below shows the 3 #6 wires going down to the underground grounding rod. The telco NID (grey plastic box) is tapped into the meter base #6 wire.

The technical manual that came with the transfer switch shows 3 connections to the transfer switch ground bar as per the sketch I made.

There isn't a need to have added the ground wires, but I have seen it engineered that way before (ground wire from meter to rod to panel), so I would leave it.
The ground wire from panel 1 to the ground wire is the one I question the most, can't think of a reason for it, can't think of a code that prohibits it.

 

[pclausen]

The ground wire from panel 1 to the ground wire is the one I question the most, can't think of a reason for it, can't think of a code that prohibits it.

Since I have not yet run the ground wire from the transfer switch to the ground rod (or as close as I can get to it), how about I just swing the rod ground wire going to panel 1 over to the transfer switch ground bar?

This way the transfer switch will have a dedicated #6 wire directly to the ground rod, and panel 1 will be grounded directly to the transfer switch instead of directly to the grounding rod.

 

[podagrower]

Since I have not yet run the ground wire from the transfer switch to the ground rod (or as close as I can get to it), how about I just swing the rod ground wire going to panel 1 over to the transfer switch ground bar?

This way the transfer switch will have a dedicated #6 wire directly to the ground rod, and panel 1 will be grounded directly to the transfer switch instead of directly to the grounding rod.

Which would give you a ground wire from the rod to the meter base, the transfer switch, and panel 2?
I've seen it engineered like that, installed it like that, and it passed inspection, so it sounds good to me.