stray voltage

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electricalperson

electricalperson

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massachusetts
has anyone here ever came across a stray voltage problem? will you be willing to share with us what you found? what test methods did you use and what you did to fix it?
 
electricalperson said:
has anyone here ever came across a stray voltage problem? will you be willing to share with us what you found? what test methods did you use and what you did to fix it?
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No but anyone with issues within 100 miles of Washington DC (maybe further) I am willing to travel and work for free.

What types of issue are you having?
 
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brian john said:
No but anyone with issues within 100 miles of Washington DC (maybe further) I am willing to travel and work for free.

What types of issue are you having?
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none i was just interested in learning more. from the video i learned that stray voltage is measured neutral to earth (the dirt)

i made a 20 ft long test lead for my simpson 260 and went outside and measured from the meter socket to earth 20 feet away and had 50 millivolts.

i went to my pool and measured from the hand rail then from the water to earth and had the same reading.

then i measured from the gas pipe to my generator to earth and had the same it wasnt phantom voltage because the needle didnt have the same arc on all voltage scales. on the 2.5 v scale it went up to around half a volt then dropped down and couldnt read any. so i switched to the 250 mv scale and got the 50 mv
 
my meter doesnt measure mv in AC mode. i just reread the manual making sure i did everything right. (still learning with the 260)
i did get 50mv on the 250mv scale but i had to switch it to DC because the needle was trying to go in the opposite direction

im going outside to measure again i will tell you what i get on the 2.5vac scale.
 
i measured again and i had .5V then it jumped up to .6V and back down to .4 and finially going back up to .5V before i came back inside.

i measured this from the meter socket to the dirt 20 feet away

i dont have ground rods at the meter only grounding is the water pipe inside. this service is probably 40 years old or so
 
You are just measuring the voltage drop on the utilty primary and secondary nuetral conductors when you take this measurement. The bigger the load and the longer the neutral conductor, the more drop you will see.
 
don_resqcapt19 said:
You are just measuring the voltage drop on the utilty primary and secondary nuetral conductors when you take this measurement. The bigger the load and the longer the neutral conductor, the more drop you will see.
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i was just watching the mike holt video again. he said you will probably see 1 volt or so depending how far you are from the substation and neutral impedance

i believe what im reading is completly normal and there is 0 problem at all. the utility neutral is fine as well.


if there was a higher voltage then there is something wrong. high is probably 3 or 4 or higher voltage.

am i understanding correctly?
 
You are understanding it correctly, but I have no idea of what the upper limit of a normal votlage drop would be. If this system has a primary neutral, I could see the votlage drop being a lot more than a few volts.
 
don_resqcapt19 said:
You are understanding it correctly, but I have no idea of what the upper limit of a normal votlage drop would be. If this system has a primary neutral, I could see the votlage drop being a lot more than a few volts.
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i am so thankful for finding this site and mikeholt.com without this site i wouldnt learn anything more. i owe my career to you guys and mike holt


im going to learn more and more about this and other problems.
 
I have worked on a few dairy barns with 'stray voltage', although we are actually looking for current that is flowing in an unintended path. Generally the problems are multiple neutral earth bonds, purposely or not. Using a reduced neutral increases the neutral voltage drop which increases the current flowing through earth or any other path that is available.
 
can you measure voltage drop on the neutral to see if its bad?

my thinking: put a load on the neutral, look in the code to find R per foot, use ohms law to figure a voltage drop across the neutral.

if voltage drop across neutral is higher than paper there might be a loose connection or bad neutral. if theres a pole mounted transformer can you measure to the GEC that comes off of the pole? if theres a pad mounted can you dig to the ground rods and measure voltage there instead of opening the transformer?

im assuming it has to be a 120v load. a 240v load wont work

will this work?
 
The power company pretty much does that.

They can pull a meter, replace it with a plug in load bank that tests for voltage drop line to line and line to neutral, I imagine they are looking mostly for a major difference between one reading and the other.

BTW sometimes power companies are the fastest way to do the testing, I figured out I had a voltage problem at my own house, I had left my 87 on record overnight and found one leg to neutral was going up and down from about 90 to 140 volts. I left a voice mail with the POCO at about 6AM and headed off to work, by 10 AM they called me and said they tested and where sending a line truck out. By noon it was fixed all no charge.
 
iwire said:
The power company pretty much does that.

They can pull a meter, replace it with a plug in load bank that tests for voltage drop line to line and line to neutral, I imagine they are looking mostly for a major difference between one reading and the other.

BTW sometimes power companies are the fastest way to do the testing, I figured out I had a voltage problem at my own house, I had left my 87 on record overnight and found one leg to neutral was going up and down from about 90 to 140 volts. I left a voice mail with the POCO at about 6AM and headed off to work, by 10 AM they called me and said they tested and where sending a line truck out. By noon it was fixed all no charge.
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wheres the fun in that :grin:
 
would this be the same for a corner grounded delta system? if the grounded conductor had stray voltage to earth would it be safe to say the grounded phase has the problem?

theres not many types of these systems around here just thinking
 
Yea this is a great site, I rarely find a day I don't learn something new, or get set straight about something I thought I knew.

If we were to combine all the years experience, of all the posters here (like some contractors do on the side of there truck)

I think it would be in the thousands of years experience. now it doesn't get any better that that:grin:
 
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