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71PA_Highboy

An Unknown but Engorged Member
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442
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Near the Triad, Lookin' at the freeway
So I have a friend looking to put in a sub panel.

Sub Panel.png



So my questions are: Does the sub panel need a ground rod?

Does the sub panel get the neutral and ground tied together.

Does the ground and neutral get tied together at the main panel?

In VA if it matters.
 
NEC no longer allows for the use of a ground rod at a sub panel. You'll need to include a ground with the feeders.

It's a sub panel, so the neutral and ground do not tie together on either end (though the neutral and ground feeding the main panel will be bonded/or on the same bar)

*In before "I put an outlet in at my cousin's house and we ran lamp cord and no ground and nothin caught on fire" :laughing:
 
Neutral and ground are tied together, always.
I'd put a ground rod in like it was a normal service.
Here in MI you gotta have 2 ground rods spaced maybe 12' apart I think.
350' is a heck of a run......

I'm not an electrician, but I have stayed at a Holiday Inn Express in the last few months.
 
JayMcJay said:
Neutral and ground are tied together, always.
I'd put a ground rod in like it was a normal service.
Here in MI you gotta have 2 ground rods spaced maybe 12' apart I think.
350' is a heck of a run......

I'm not an electrician, but I have stayed at a Holiday Inn Express in the last few months.
Click to expand...
I rest my case. :laughing:

OP don't do this.
 
JayMcJay said:
Neutral and ground are tied together, always.
I'd put a ground rod in like it was a normal service.
Here in MI you gotta have 2 ground rods spaced maybe 12' apart I think.
350' is a heck of a run......

I'm not an electrician, but I have stayed at a Holiday Inn Express in the last few months.
Click to expand...
I remember something about not tying the neutral and ground on the sub panel, but leaving the panel to be grounded by the ground rod... or maybe it was reversed and I am ass backwards in my remembery...
 
Hold up...rules are different depending on if this is an attached structure or not. Same building you just run 4 conductors (hot, hot, neutral, ground) don't bond anything at sub panel, no extra ground rod, super simple. Different building it's been a while so I don't know latest code but I know it was separate ground and maybe bonding? but not 100% on that.
 
Tin Roof said:
NEC no longer allows for the use of a ground rod at a sub panel. You'll need to include a ground with the feeders.

It's a sub panel, so the neutral and ground do not tie together on either end (though the neutral and ground feeding the main panel will be bonded/or on the same bar)
Click to expand...

Hangon here.
(though the neutral and ground feeding the main panel will be bonded/or on the same bar)
Doesn't that mean they're tied together? They're attached to a common buss. What part about that isn't 'tied together'?

And you're saying that you can't have a ground rod? Like, you're not allowed to have one on a subpanel? Not as a substitute for the ground coming from the main, but as an ancillary?
 
JayMcJay said:
Neutral and ground are tied together, always.
I'd put a ground rod in like it was a normal service.
Here in MI you gotta have 2 ground rods spaced maybe 12' apart I think.
350' is a heck of a run......

I'm not an electrician, but I have stayed at a Holiday Inn Express in the last few months.
Click to expand...
Maybe you should try a best western next time..... There is more fake news in that than a CNN article
 
JayMcJay said:
Neutral and ground are tied together, always.
I'd put a ground rod in like it was a normal service.
Here in MI you gotta have 2 ground rods spaced maybe 12' apart I think.
350' is a heck of a run......

I'm not an electrician, but I have stayed at a Holiday Inn Express in the last few months.
Click to expand...

Obviously, as you just told him to do it about as illegal as possible. :flipoff2:

No ground rod needed. Run 4 wire URD, or put conduit in and run thhn aluminum. Keep neutral and ground separate after the first means of disconnect.

Volt drop is a bitch, you're going to need 2/0 or bigger to support 60A. 2/0 aluminum gets you down to 3% drop. :laughing:
 
JayMcJay said:
Hangon here.
(though the neutral and ground feeding the main panel will be bonded/or on the same bar)
Doesn't that mean they're tied together? They're attached to a common buss. What part about that isn't 'tied together'?

And you're saying that you can't have a ground rod? Like, you're not allowed to have one on a subpanel? Not as a substitute for the ground coming from the main, but as an ancillary?
Click to expand...
The main panel has to have the neutral and ground bonded. Whoever installed it either did separate neutral and ground bars with a jumper or used the same bar. If it’s separate bars with a jumper you land the neutral and ground on the appropriate bars. If they used the same bar you use the same bar. That is at the main panel end only.

A sub panel has to have a separate ground from the main panel. Ground rods at sub panels are no longer allowed.
 
Since you are 350' away, I would assume its in a different structure. If this is the case the main panel would have a ground rod and the neutral and ground would be bonded together. The sub panel would not have the neutral to ground bond but it would have a ground rod. I just had this very discussion with a electrical engineer the other day.

see below from Mike Holt forum:
1716915901229.png
 
JayMcJay said:
Hangon here.
(though the neutral and ground feeding the main panel will be bonded/or on the same bar)
Doesn't that mean they're tied together? They're attached to a common buss. What part about that isn't 'tied together'?

And you're saying that you can't have a ground rod? Like, you're not allowed to have one on a subpanel? Not as a substitute for the ground coming from the main, but as an ancillary?
Click to expand...

You bond the grounded and grounding conductors together at the first means of disconnect. If you keep tying them together you create ground loops that cause issues.


If you put in auxillary ground rods you can cause stray current underground. It's why they got rid of 3 wire services. You'd have a broken wire and never know it except that you keep getting shocked if you step in the wrong spot :lmao:

Grounding and bonding is all about creating an equipotential plane of potential. It's pretty easy to create a difference if potential and have fun things happen. That's when you call me :flipoff2:
 
Chevy_man said:
You bond the grounded and grounding conductors together at the first means of disconnect. If you keep tying them together you create ground loops that cause issues.


If you put in auxillary ground rods you can cause stray current underground. It's why they got rid of 3 wire services. You'd have a broken wire and never know it except that you keep getting shocked if you step in the wrong spot :lmao:

Grounding and bonding is all about creating an equipotential plane of potential. It's pretty easy to create a difference if potential and have fun things happen. That's when you call me :flipoff2:
Click to expand...
Years ago when I did work on farms we'd get at least one call a year "my cows/pigs are getting nailed at the waterer and I've lost a couple". Show up and ask if they've done any work themselves "yep, I ran power to the heater in the waterer". Did you ground it? "of course, tied the neutral to the frame". :homer:
 
Chevy_man said:
You bond the grounded and grounding conductors together at the first means of disconnect. If you keep tying them together you create ground loops that cause issues.


If you put in auxillary ground rods you can cause stray current underground. It's why they got rid of 3 wire services. You'd have a broken wire and never know it except that you keep getting shocked if you step in the wrong spot :lmao:

Grounding and bonding is all about creating an equipotential plane of potential. It's pretty easy to create a difference if potential and have fun things happen. That's when you call me :flipoff2:
Click to expand...

nbjeeptj and you both make compelling arguments...

Who is right?
 
Article 250-32(A) has remained unchanged and if you are feeding a structure from a different structure you have to have a grounding electrode (ground Rod or equivalent) at the 2nd structure. If its a branch circuit or feeder, feeding this 2nd structure you feed it with 4 wires and don't bond the neutral and ground at the sub panel.
 
Last edited:
When I built my addition years ago, I followed a similar set up.

The sub panel had its own separate ground rod, tied to the new ground.
The sub panel had its neutral / ground bond separated. That meant that the Hot / Neutral / Ground wiring from the sub, to the main, were continuous.
Building Inspector was the one that advised me on this set up.
 
JayMcJay said:
So what's the possible potential between the ground and the neutral in the diagram above?
Click to expand...

Depends. Sometimes nothing, but if something goes wrong it could be 240v. :flipoff2:

71PA_Highboy said:
nbjeeptj and you both make compelling arguments...

Who is right?
Click to expand...

Depends if it's just a sub panel on a post, or if it's feeding a new structure. :homer:

I assumed farm use where it's feeding stand alone equipment from the info provided. Since you didn't say you were wiring a new building.
 
Need 2 hots, ground, neutral from main to subpanel. If seperate building, 2 ground rods at subpanel as well
 
Repeating some of the "good" info above.....You only bond the ground and neutral at the main panel (service entrance). All feeders MUST have separate neutral and ground wiring ran to main panel. Sub panel in separate structure does require ground rod (actually 2 rods no less than 6 feet apart, NEC 250.68(A))

60A service at 350ft needs much larger wire than 4/4/4/4. Your NEC maximum branch voltage drop should not exceed 3%.
2 / 2 / 2 / 4 COPPER is 3.2% voltage drop over 350ft. Bad Zuki is correct for #1 Copper
1/0 / 1/0 / 1/0 / 2 ALUMINUM is 3.4% voltage drop over 350ft. 2/0 gets you down to 2.8% drop in aluminum.

Beware that when running large gauge wire for a long feeder run like yours, you need to confirm that your terminals on your breakers (disconnects, etc.) are large enough to fit the conductor size you are using. I had to oversize to a 100 amp disconnect for my 50A barn feeder (330 foot run) due to lug size issues.
 
JayMcJay said:
Neutral and ground are tied together, always.
I'd put a ground rod in like it was a normal service.
Here in MI you gotta have 2 ground rods spaced maybe 12' apart I think.
350' is a heck of a run......

I'm not an electrician, but I have stayed at a Holiday Inn Express in the last few months.
Click to expand...
No. The neutral is bonded to the ground at the first means of disconnect ONLY. No additional ground rod is needed.

Edit: re: ground rod, I didn’t catch this was a separate structure.
 
Tin Roof said:
No.
Click to expand...

Well, yes on ground, but no on bond...that was the part I wasn't sure on, it might be with generators feeding transfer switches that I'm thinking about the bonding part depending on if it's floating or not. Last thing I did was a generator/solar setup shared between 3 buildings, was a cluster fuck on the mind.
 
The fact that old vs new and NEC vs CEC demand different things tells me there isn't very good consensus among the experts, despite the AC power itself being the same as always.

Multiple ground rods on a property (appreciable diatance between) can cause circulating currents. However, local grounding to a farm structure is preferred for the livestock's sake.

Whatever you do, run 4 conductors (3 + bond) that 350'. (ACWU ia the preferred one-shot alum conductor armoured cable in canada.) Then whether you decide to use a ground rod or not is a minor detail.
 
Im running a ground rod on my sub panel but it ties in off the bottom of the meter and not the main panel. Guessing it makes a difference.
 
JayMcJay said:
What's the scenario that would get you 240V from ground to neutral?
Click to expand...
Two conductors burnt together. Happened at my buddy's place. Old 3-wire feed to a well shack. The 120v went away and 240v only... Ground/neutral hot and no breakers tripped.
 
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