amperage to the ground rod

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ASK_EDDIE

ASK_EDDIE

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Called for incandesent lamps burning out in a house. The panel is outside at the meter base, I clamped on to the ground wire going to ground rod from the neutral bar and I have about 2.5 amps . I did remove it from the bar to see if it would draw an arc but it didn't . I pulled the meter and to my surprise it still had anywhere from .5 amps to to 1.3 . I assume I'm getting something back from the from the transformer. With the meter pulled and removing the ground wire at the bar all current flow stops. This is and underground service to a ground mounted transformer.
I've had the utility "oncor" out they're trying to tell me the is perfectly normal.It's not normal,and they don't seem to have a clue. I guess I dont either and so thats why I'm asking for input, is it a floating neutral open neutral ,lost its bond.bad transformer?
 
when you turn everything off at the house do you still have a current flow on the GEC?
 
The burning out of lamps is probably due to the fact that they are using 120v bulbs. Try using 130V bulbs and see if the problem with the lights is solved
 
Check the neighbor(S) and see who has a loose/No connection on their neutral. Repair their connection and probably the reading on your ground rod will go away.
 
First those readings can be quite normal and very common, we must remember that the earth is in parallel with the neutral of this service and current will take all paths back to the source (transformer), the neighbors service the its grounding as well, even a ground rod of 50 ohms will allow 2 amps of current to flow, but if you turned off all A leg breakers as well as any two pole breakers then measured the voltage on the B leg with some heavy loads turned on if it should drop below 120 volts on one leg and goes over 120 volts on the other leg then you could have a secondary neutral problem, a Small voltage rise and fall can be normal if there is some voltage drop on the service conductors, also if there is a water pipe ground connection and the street side of this connection is copper or iron pipe then it can be also masking a bad neutral, remember to shut off the main before turning off all the A leg breakers as if you do have a bad neutral you could possibly over voltage equipment in the house if you start turning off breakers to force an unbalance condition with the main still on, also keep in mind that disconnecting any grounding can increase the voltage on the services grounding to earth so you want to make sure that no one at the house is in a position to touch anything grounded to the service even the water pipes or valves, also if you do this with all the breakers on both A and B legs turned on you could risk damaging the customers equipment from over voltage, always turn off the main and turn off all the breakers on one leg of the panel before disconnecting the any grounding to unmask a parallel neutral path that could be masking the neutral problem.

Also keep in mind that if you force an unbalanced condition on a transformer that feeds other houses also, if the bad neutral connection is at the transformers X0 bushing (neutral) you could also be causing over voltage in these other houses because they will still have loads on the leg that will go higher, I would not fully load one leg at first, just load it a little at a time then check each leg to neutral voltage before going any more to see if you start dropping voltage on the one your loading and rising the voltage on the other unloaded leg, if the unloaded leg reaches 125-130 volts while the loaded one goes down to 115-110 volts then stop there and check to see if this voltage imbalance is also at the meter on the line side of it, if it is then call the utility, these types of problems must be done in steps to make sure you don't cause other damage from over voltageing other equipment in this house or any neighbors that might share the same transformer.

Another test I do when I find a little current on the service grounding is to test for voltage from the service grounding or even the meter can to remote earth by sticking a screw driver or short rod into earth about 20' from the service and run a wire to the meter so I can use a DVM or other high impedance voltage meter (not a wiggy) to see if I have any voltage over 10 volts between this earth test rod which is the voltage that tells me that there maybe a primary neutral to the transformer connection problem, although not a very common problem it does happen, generally the current will be low but the voltage can be high, a secondary neutral problem is a higher current but the voltage is normally low depending upon how well the service is balanced, but when you start seeing over a 10 volt reading but a low current then a primary neutral to the transformer flag rises because this could be very dangerous, also never disconnect any grounding if this is ever discovered because you could end up having the primary voltage on the grounding of this house as the transformer tries to return its current through this path.

If you ever suspect a bad primary neutral to a transformer connection from measuring the voltage to a remote earth point then ask the utility to test the primary neutral at the transformer to make sure it is returning its current to the MGN, they do this by using a HV clamp on amp meter to make sure the transformer is returning its current through the correct wire that connects to the MGN, some utility's don't use a WYE local distribution system so in these cases this would not happen, but many do like ours that uses a 12400/7200 volt WYE system for local distribution.

another good sign of a bad primary neutral to transformer connection is if the customer has experienced and underground water pipe leak problems and they had a plumber make repairs with PVC to stop the problem or had a dielectric union installed after the leaks were repaired, also after this is done you start seeing higher voltages to earth readings many times in the 20 volts or above,
 
Has to be some pretty conductive soil to carry 2.5 amps on a ground rod @ 120 volts anyway.

I agree this current is coming from somewhere else, and it could even be POCO primary current because of a bad POCO neutral connection somewhere.

Did you check voltage readings between the electrode and the neutral when you had them disconnected?

How about disconnecting power, disconnecting incoming neutral and then check voltage from incoming as well as premises neutral to "earth"? This should help verify that it is coming from utility side of the service equipment.

Most of the time this kind of current is deemed normal, but if you were in a situation with a boat dock, or similar installation, many of the electrocution stories that have happened at these places fit right in with what you have here, nothing wrong on the premises but an electrical grounding system is operating at a voltage above true earth. These incidents don't happen at a properly installed swimming pool because of all the bonding done at a swimming pool, but it is a pretty unrealistic task to create equipotential bonding grid at a large body of water.
 
ASK_EDDIE said:
Called for incandesent lamps burning out in a house. The panel is outside at the meter base, I clamped on to the ground wire going to ground rod from the neutral bar and I have about 2.5 amps . I did remove it from the bar to see if it would draw an arc but it didn't . I pulled the meter and to my surprise it still had anywhere from .5 amps to to 1.3 . I assume I'm getting something back from the from the transformer. With the meter pulled and removing the ground wire at the bar all current flow stops. This is and underground service to a ground mounted transformer.
I've had the utility "oncor" out they're trying to tell me the is perfectly normal.It's not normal,and they don't seem to have a clue. I guess I dont either and so thats why I'm asking for input, is it a floating neutral open neutral ,lost its bond.bad transformer?
Click to expand...

long time ago in an electronics test shop, there were two ground rods driven about 8' apart.
if you hooked a wire between them, you could measure 10 to 20 amps between them, and
if you read the potential between them, it was something like 20 volts open circuit, so it wasn't
just ghost voltage.... and nobody was able to figure out why this was happening. we disconnected
the rods from everything, and still had the situation.

but like a number of people have said, start looking at the neighbors panels.

in one of the marinas near here, there was a 70' chris craft, aluminum hull, that was
leaking 15 amps of 240 into the water... the electroalysis was eating both his and
everyone else's zincs, and props, etc.
 
Fulthrotl said:
long time ago in an electronics test shop, there were two ground rods driven about 8' apart.
if you hooked a wire between them, you could measure 10 to 20 amps between them, and
if you read the potential between them, it was something like 20 volts open circuit, so it wasn't
just ghost voltage.... and nobody was able to figure out why this was happening. we disconnected
the rods from everything, and still had the situation.

but like a number of people have said, start looking at the neighbors panels.

in one of the marinas near here, there was a 70' chris craft, aluminum hull, that was
leaking 15 amps of 240 into the water... the electroalysis was eating both his and
everyone else's zincs, and props, etc.
Click to expand...

Are you sure that was a Chris Craft? I don't think they make 70' long boats, and I am pretty sure they are all fiberglass.
 
Fulthrotl said:
long time ago in an electronics test shop, there were two ground rods driven about 8' apart.
if you hooked a wire between them, you could measure 10 to 20 amps between them, and
if you read the potential between them, it was something like 20 volts open circuit, so it wasn't
just ghost voltage.... and nobody was able to figure out why this was happening. we disconnected
the rods from everything, and still had the situation.

but like a number of people have said, start looking at the neighbors panels.

in one of the marinas near here, there was a 70' chris craft, aluminum hull, that was
leaking 15 amps of 240 into the water... the electroalysis was eating both his and
everyone else's zincs, and props, etc.
Click to expand...

As far as I can see, there is only one basic explanation for the voltage between your two ground rods:
Some circuit is driving enough current through the earth that the resistive drop between the two locations is 20 volts. This current could either be from a major ground fault in your own equipment or wiring or from an outside source such as a failed utility primary neutral.
Opening the main breaker would tell you which of the two it was and get a good start narrowing it down from there.
 
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