Ground rod error?

[wef]

About 30 years ago I installed a boat lift for a 16' runabout. It has a 1/2 hp motor. My first mistake was running 12-2 200' from the main panel in the house. It worked OK until I got a slightly bigger boat. If the motor is stopped on the way up, it doesn't have enough power to continue upwards. There is a breaker box about 30' from the motor and the up/down switch. I put in a ground rod at that box and bonded the white and bare wires with the rod. Then the lift had no problem with even a bigger boat half full of water. The only thing done on the lift for the last 25 years has been new motor belts. I'm reading a lot of posts indicating I did a great big no-no but I would think any electrical faults would be contained right there at the box and ground rod. Anyway it goes, I'd like to get it correct as I'm trying to clean up 50 years of mickey mouse fixits to prepare the house for sale. Any help would be greatly appreciated.

 

[kd3pc]

southern md has several good electrical contractors who are decent marina electricians and have the tools and test gear to make sure it is done right. Improper grounding can kill. In the water (leakage) as well as on the land. You are lucky that great big no-no has not hurt anyone.

If you do it yourself, assume to trash everything you have now and replace it. ANY electrical that is over 6 - 8 years old, on the water, is on borrowed time.

Be aware that many people who buy on the water homes, will have a qualified marine electrician to check out the dock/pier electrical, as well as the proper disclosures about it.

 

[ishiboo]

Throwing your own ideas of grounding out there when it comes to water is a particular bad idea, not only for personal safety but the safety of your equipment.

If that truly helped your situation like you said (which I doubt), that means that you are passing some of the current that should be ONLY on the neutral on both the neutral and ground. BAD idea. Even worse, a portion of that current could be passing between the ground rods themselves.

Additional neutral/ground bond = another BAD idea.

Fix this scenario immediately.

This absolutely needs both adequate wire, and an acceptable GFCI. If the GFCI trips which it may on an old boat lift, there IS leakage current that you need to rectify, even if it's replacing the driving guts of the lift.

 

[Speedy Petey]

I have NO idea why doing this would have solved the problem. Sticking a rod in the ground would have NOTHING to do with the functionality of a circuit.

Either way, 30 years ago it would have been perfectly legal to have a remote sub-panel fed with a 3-wire feeder with the neutral bonded to ground. Personally I'd have someone look at it. You may be able to "get by" with a minimal fix if this whole installation is 30 years old.
They CANNOT make you upgrade to newer codes just because you are selling the house.

 

[kd3pc]

They CANNOT make you upgrade to newer codes just because you are selling the house.

Actually they can when it has the potential of killing someone who is wading or falls in to the water.

I know several marinas on Chesapeake Bay that were basically shut down when a kid swimming off the back of the boat in the marina, was electrocuted and died. The mains were turned off and locked off, until qualified and experienced marine (water) electricians could verify that no current was leaking in to the water where these types of "ground" had been made and ignored that were now lethal.

Homes are in the same boat.

 

[AllDodge]

For fresh water areas controlled by the USACE
http://www.swl.usace.army.mil/Portals/50/docs/beaverlake/Dock%20Electric%20Systems.pdf

National Electrical Code
http://catalog.nfpa.org/NFPA-70-National-Electrical-Code-NEC-P1194.aspx?icid=D531

Lake of the Ozarks
http://www.lakeozarkshomes.com/Electrical Installation Requirements for Private Boat Docks 001.pdf

 

[dw1]

I would turn this off, I would be concerned about the person that was bare footed,(damp outside) leaned over to touch something on the boatlift "metal" and became a better ground than whats out there and was electrocuted. Lets look at 200' away from panel, thats 200' down to boatlift and 200' back up to panel for the complete circuit (400') pretty good voltage drop on your motor. You drove a ground rod that is now in parallel with your main service and have the neutral and ground tied to it, another NEC violation. A GFCI at the house would not hold up on this setup, to much leakage to ground through added ground rod.

Electricity can travel approx. 20-25' in water.

 

[rlitman]

I have NO idea why doing this would have solved the problem. Sticking a rod in the ground would have NOTHING to do with the functionality of a circuit.

Wrong. Voltage loss happens on both the hot and neutral wires in a circuit. In this case, the ground loop created is carrying some of the neutral current, which would reduce the voltage loss by no more than half, but that might still be enough.

Yes, this is very bad.

 

[ishiboo]

Wrong. Voltage loss happens on both the hot and neutral wires in a circuit. In this case, the ground loop created is carrying some of the neutral current, which would reduce the voltage loss by no more than half, but that might still be enough.

Yes, this is very bad.

I have NO idea why doing this would have solved the problem. Sticking a rod in the ground would have NOTHING to do with the functionality of a circuit.

Either way, 30 years ago it would have been perfectly legal to have a remote sub-panel fed with a 3-wire feeder with the neutral bonded to ground. Personally I'd have someone look at it. You may be able to "get by" with a minimal fix if this whole installation is 30 years old.
They CANNOT make you upgrade to newer codes just because you are selling the house.

You both are wrong, and it's unlikely the ground loop is carrying much if any current.

The difference between this and a 3-wire feeder, is a 3-wire feeder has 2 hots and a neutral and no ground... HIS feed now has one hot and essentially two neutrals. This is 120v not 240v.

This is a 3-wire service with hot and ground/neutral. He not only added a ground rod, but bonded the ground and neutral conductors close to the boat lift which was not there before. This made both the neutral and ground current-carrying conductors, and cut down on the overall resistance for HALF the length of the circuit. He basically upsized half the run by paralleling two #12 conductors.

 

[ishiboo]

I would turn this off, I would be concerned about the person that was bare footed,(damp outside) leaned over to touch something on the boatlift "metal" and became a better ground than whats out there and was electrocuted. Lets look at 200' away from panel, thats 200' down to boatlift and 200' back up to panel for the complete circuit (400') pretty good voltage drop on your motor. You drove a ground rod that is now in parallel with your main service and have the neutral and ground tied to it, another NEC violation. A GFCI at the house would not hold up on this setup, to much leakage to ground through added ground rod.

Electricity can travel approx. 20-25' in water.

If this was installed correctly, a GFCI at the house would work fine as it looks only at the current passing through the hot and neutral. Working properly, there is no reason for any current to "leak" on the ground rod, its purpose is for lightning protection. Even if the boat lift's installation instructions require its own ground rod. (An in-water metal lift probably would never as it's really well-grounded to begin with!)

 

[dw1]

If this was installed correctly, a GFCI at the house would work fine as it looks only at the current passing through the hot and neutral. Working properly, there is no reason for any current to "leak" on the ground rod, its purpose is for lightning protection. Even if the boat lift's installation instructions require its own ground rod. (An in-water metal lift probably would never as it's really well-grounded to begin with!)

A GFCI at the house wouldnt work, I bet you have less resistance at the ground rod, since the white and bare are connected to this, therefore a GFCI not resetting. Take an amprobe and measure the current on the white/bare at the ground rod, whether we call it leakage (I guess really its not leakage) but say over time that connection deteriorates, someone gets between and creates a less resistance to ground path and what happens!!
Is this motor mounted to the metal frame of the boat lift? I am not familiar with them, is it mounted to the dock?
I would still turn it off and install correctly.

 

[ishiboo]

A GFCI at the house wouldnt work, I bet you have less resistance at the ground rod, since the white and bare are connected to this, therefore a GFCI not resetting. Take an amprobe and measure the current on the white/bare at the ground rod, whether we call it leakage (I guess really its not leakage) but say over time that connection deteriorates, someone gets between and creates a less resistance to ground path and what happens!!
Is this motor mounted to the metal frame of the boat lift? I am not familiar with them, is it mounted to the dock?
I would still turn it off and install correctly.

As I said, if installed properly. The neutral-ground bond "in the yard" is NOT allowed and MUST be removed.

If everything is installed properly and it trips a GFCI, it needs to be repaired or replaced.

 

[wyliesdiesels]

Amazing how so many continue to confuse grounding electrodes and EGCs/grounds.

This is just the reason why i wish a moderator would post a sticky of the thread i started on the differencr between grounding electrodes and EGCs!

A ground rod serves a different purpose than does an equipment grounding conductor/ground. Before u do any work, familiarize yourself with both.

About 30 years ago I installed a boat lift for a 16' runabout. It has a 1/2 hp motor. My first mistake was running 12-2 200' from the main panel in the house. It worked OK until I got a slightly bigger boat. If the motor is stopped on the way up, it doesn't have enough power to continue upwards. There is a breaker box about 30' from the motor and the up/down switch. I put in a ground rod at that box and bonded the white and bare wires with the rod. Then the lift had no problem with even a bigger boat half full of water. The only thing done on the lift for the last 25 years has been new motor belts. I'm reading a lot of posts indicating I did a great big no-no but I would think any electrical faults would be contained right there at the box and ground rod.[/] Anyway it goes, I'd like to get it correct as I'm trying to clean up 50 years of mickey mouse fixits to prepare the house for sale. Any help would be greatly appreciated.

As i said, a grounding electrode such as a rod has NOTHING to do with fault current. A grounding rod is for lightning, to provide a reference to ground and keep voltage stable. Unless u have a detached structure, the ground rod was unnecessary and a waste of money! A rod is only required for detached structures. Contrary to popular belief, the earth is poor at conducting electricity and fault current wont flow from a ground rod back to the electrical panel allowing a breaker to trip. This is just the reason why we have equipment grounding conductors!

Wrong. Voltage loss happens on both the hot and neutral wires in a circuit. In this case, the ground loop created is carrying some of the neutral current, which would reduce the voltage loss by no more than half, but that might still be enough.

Yes, this is very bad.

No speedy petey was correct. If u actually read what he said u would have realized He was saying that a ground rod would not help the OPs situation for the above reasons i stated.

A GFCI at the house wouldnt work, I bet you have less resistance at the ground rod, since the white and bare are connected to this, therefore a GFCI not resetting. Take an amprobe and measure the current on the white/bare at the ground rod, whether we call it leakage (I guess really its not leakage) but say over time that connection deteriorates, someone gets between and creates a less resistance to ground path and what happens!!
Is this motor mounted to the metal frame of the boat lift? I am not familiar with them, is it mounted to the dock?
I would still turn it off and install correctly.

As i said above, ground rod has nothing to do with the fault current path. So fault current or any current for that matter wont be flowing through the ground rod through the earth through the ground rod at the service panel and into the panel...

 

[Syberia]

As i said above, ground rod has nothing to do with the fault current path. So fault current or any current for that matter wont be flowing through the ground rod through the earth through the ground rod at the service panel and into the panel...

The neutral and ground are bonded at the subpanel, and also attached to the ground rod. At 200' between the two ground rods, I bet there's enough conductivity to allow 5 ma of current to flow, creating a ground fault in the neutral that would trip a GFCI at the house. I've verified this by (accidentally) dropping a live extension cord in a puddle of water while working at the end of my 300' driveway. The GFCI it was attached to did indeed trip, because there was enough of a path for a small amount of current to leak back to the panel. At least, this is my interpretation of what the post was trying to say.

Of course, a GFCI at the house would trip anyways because the EGC is connected to the neutral, but that's beside the point.

 

[theoldwizard1]

The ground rod DOES create a "ground loop". Disconnect the "bond" (white to bare) and measure the voltage between those two conductors. If there is voltage ("potential") then there can be current. How much current is unknown.

Wylie. after eliminating the ground rod, would installing a GFCI outlet at the box in front of the switch be "proper"/safest solution ?

 

[dw1]

I re-read the original post, he bonded the neutral and ground wire to the ground rod, my bad, I thought I had read that he connected the white/bare to the ground rod, that's what my major concern and replies were about.

 

[wyliesdiesels]

Folks theres 2 separate things here.

The first is the grounding electrode. The earth is a poor conductor of electricity. For example, when u have an open neutral on a main service, current doesnt flow from the ground rod at your service panel through the earth and into the ground rod at the transformer and into the neutral/center tap on the transformer. If it did, then we wouldnt experience the issues associated with an open neutral where one leg is above 120v and the other is below 120v, such as 170v and 70v.

The other issue is the neutral and ground bond. This does create a hazard and should be corrected. However, it sounds like this is a single circuit. And i assume there is no parrallel metallic pathways between the house and circuit destination. If this terminates in the main service panel, then neutral and ground are at the same potential already. The only hazard that is present is with someone touching a metal enclosure, which is bonded to the neutral and a hot leg, thus shocking themselves. The neutral and ground bond should be removed and GFCI should be installed at the begginning of the circuit!

The neutral and ground are bonded at the subpanel, and also attached to the ground rod. At 200' between the two ground rods, I bet there's enough conductivity to allow 5 ma of current to flow, creating a ground fault in the neutral that would trip a GFCI at the house. I've verified this by (accidentally) dropping a live extension cord in a puddle of water while working at the end of my 300' driveway. The GFCI it was attached to did indeed trip, because there was enough of a path for a small amount of current to leak back to the panel. At least, this is my interpretation of what the post was trying to say.

Of course, a GFCI at the house would trip anyways because the EGC is connected to the neutral, but that's beside the point.

In your example, the GFCI tripped because current was flowing on the EGC in the cord.

Yes the neutral to ground bond should be removed for the reason i said above.

The ground rod DOES create a "ground loop". Disconnect the "bond" (white to bare) and measure the voltage between those two conductors. If there is voltage ("potential") then there can be current. How much current is unknown.

Wylie. after eliminating the ground rod, would installing a GFCI outlet at the box in front of the switch be "proper"/safest solution ?

Explain to me how there would be potential between a neutral and ground THAT TERMINATE ON THE SAME BAR in the main service panel? The OPs circuit terminates in the main service panel.

Yes the bond should be removed to prevent potential shock from a metal enclosure that is bonded to neutral via the neutral-ground bond!

 

[theoldwizard1]

Explain to me how there would be potential between a neutral and ground THAT TERMINATE ON THE SAME BAR in the main service panel? The OPs circuit terminates in the main service panel.

I can not, but I know it is true ! It has something to do with the resistance of the earth between those 2 points and the resistance of the neutral wire.

As I said, separate the ground and the neutral at the remote location. Insert a volt meter. It will read a few volts. How much current is a different story.

No two lengths of copper wires are "ideally" the same. Precisely cut 1,000' lengths of copper wire will have a slightly different resistance, when measured with a precision ohm meter.



GHCI at the remote location or better using a GFCI breaker at the load center ?

 

[sberry]

Use a gfci before it leaves the house.

 

[theoldwizard1]

Explain to me how there would be potential between a neutral and ground THAT TERMINATE ON THE SAME BAR in the main service panel?

Seebeck effect or Thermoelectric effect

 

[rlitman]

You both are wrong, and it's unlikely the ground loop is carrying much if any current.

The difference between this and a 3-wire feeder, is a 3-wire feeder has 2 hots and a neutral and no ground... HIS feed now has one hot and essentially two neutrals. This is 120v not 240v.

This is a 3-wire service with hot and ground/neutral. He not only added a ground rod, but bonded the ground and neutral conductors close to the boat lift which was not there before. This made both the neutral and ground current-carrying conductors, and cut down on the overall resistance for HALF the length of the circuit. He basically upsized half the run by paralleling two #12 conductors.

Yes, he paralleled the neutrals. But you cannot say there is not much current through the ground rods without measuring it, and I suspect that in his soil conditions (near the water implies wetter soil with high electrolyte content meaning ground rods are especially effective), the ground resistance would be extremely low. How much current flows through the ground loop would be determined by Kirchoff's law, but you could easily measure it with a clamp meter.

You can rest assured that if this circuit were on a GFCI breaker, it would also not work.

 

[ishiboo]

Yes, he paralleled the neutrals. But you cannot say there is not much current through the ground rods without measuring it, and I suspect that in his soil conditions (near the water implies wetter soil with high electrolyte content meaning ground rods are especially effective), the ground resistance would be extremely low. How much current flows through the ground loop would be determined by Kirchoff's law, but you could easily measure it with a clamp meter.

You can rest assured that if this circuit were on a GFCI breaker, it would also not work.

He paralleled the EGC and neutral... they're not supposed to both be neutrals

Absolutely, that's why I said "not much if any"... it could definitely have some.