JSM8786
JMann
I have a boat dock on a lake in northeast Georgia. The dock is supplied by a 20 amp 110 GFCI protected 12 gauge 3 wire circuit from the house to a power pole near the water where a twist lock disconnect plugs in and leads to the floating dock. The power to the dock is for an air type boat lift, a couple of lights and a couple of 110 outlets. The dock meets all the corp or engineers electrical requirements and all electrical codes and was signed off on by a licensed electrician in March. I test the GFCI at least twice a month.
While swimming one evening, I touched the metal bunks of the boat lift and felt a tingle. I immediately searched and found a local licensed electrician to come out and inspect the dock to determine why I was feeling the tingle. While waiting a few days for the electrician, I did some troubleshooting myself and using the clamp method I read about online, discovered that I had voltage/current leakage on the conduit supplying the power the dock. I isolated the three wires in the conduit. Clamping the black and white together, the reading was 0. When I isolated the green wire and clamped it, the readings on the wire were 30 milivolts and .25 amps or 250 miliamps. i assumed I had a problem in the house with something going to ground so I flipped the main disconnect at the panel and retested. Still had the same readings on the green ground wire with all power to house in the off position. Obviously disconnected everything until the electricians arrival.
A few days later the electrician arrived and immediately said he was very familiar with the problem and it was related to stray voltage from the power company. He incidcated that the way to correct this is to disconnect the ground from the house at the lakeside power pole and drive a ground rod and connect the dock ground to this ground rod. I questioned how it would be safe to disconnect the ground to the panel since rods are really only lightening protection? His response is that by code, homes without ground wires use GFCI protection like I have on the dock and this meets code.
After he left, I continued to read and became more and more uncomfortable with my ground being disconnected to the main panel so I called the power company to ask about stray voltage/current. Guy was very nice and has agreed to dispatch a truck to check power connections to my home. Said it was very unusual to have stray voltage/current problems in my neighborhood due to the underground system but they would check. I am awaiting a response.
So my questions are:
1. Are the voltage/current readings I am getting dangerous to swimmers?
2. Why would I get a higher current reading than volts? The 250 miliamp reading is what worries me.
3. Is disconnecting the ground to panel the correct way to handle this situation?
4. Is there anything else I can try?
I have done basic electrical but realize I am over my head looking for professional advice.
While swimming one evening, I touched the metal bunks of the boat lift and felt a tingle. I immediately searched and found a local licensed electrician to come out and inspect the dock to determine why I was feeling the tingle. While waiting a few days for the electrician, I did some troubleshooting myself and using the clamp method I read about online, discovered that I had voltage/current leakage on the conduit supplying the power the dock. I isolated the three wires in the conduit. Clamping the black and white together, the reading was 0. When I isolated the green wire and clamped it, the readings on the wire were 30 milivolts and .25 amps or 250 miliamps. i assumed I had a problem in the house with something going to ground so I flipped the main disconnect at the panel and retested. Still had the same readings on the green ground wire with all power to house in the off position. Obviously disconnected everything until the electricians arrival.
A few days later the electrician arrived and immediately said he was very familiar with the problem and it was related to stray voltage from the power company. He incidcated that the way to correct this is to disconnect the ground from the house at the lakeside power pole and drive a ground rod and connect the dock ground to this ground rod. I questioned how it would be safe to disconnect the ground to the panel since rods are really only lightening protection? His response is that by code, homes without ground wires use GFCI protection like I have on the dock and this meets code.
After he left, I continued to read and became more and more uncomfortable with my ground being disconnected to the main panel so I called the power company to ask about stray voltage/current. Guy was very nice and has agreed to dispatch a truck to check power connections to my home. Said it was very unusual to have stray voltage/current problems in my neighborhood due to the underground system but they would check. I am awaiting a response.
So my questions are:
1. Are the voltage/current readings I am getting dangerous to swimmers?
2. Why would I get a higher current reading than volts? The 250 miliamp reading is what worries me.
3. Is disconnecting the ground to panel the correct way to handle this situation?
4. Is there anything else I can try?
I have done basic electrical but realize I am over my head looking for professional advice.