due to the bonding would also feed into the structure's ground resulting in charged appliance chassis.Quote from Ethan
Not to highjack this thread but this is what I am experiencing in my home.I have loosened and re-tightened all connections in the panel but still have this issue.Could the problem be in the meter base.
Tony
First, if you have issues with respect to energized appliance chasis, I would really *strongly* urge you to hire an experienced electrician to diagnose and correct the issue. This is a very dangerous issue to have and a number of potential causes can come into play to contribute to this issue which can require someone with substantial experience and a strong knowledgebase to troubleshoot.
In the interest of full disclosure, I am not an electrician, my grandfather was the electrician and I spent much of my childhood, teens and early 20's assisting him on his jobs.
Some of the common causes for energized appliance chasis (in no particular order) follow. This list should not be considered exhaustive and it is not uncommon for multiple causes to contribute to the problem, so it may not be any singular cause.
1) Miswired receptacles. When an inexperienced DIYer rewires a receptacle the outcome is often potluck. Hot-Neutral miswiring is very common, but I have also seen hot grounds before. A very inexpensive troubleshooter for 120V receptacles is available at nearly every hardware store, it is a simple plugin device (usually yellow or orange in color) with 3 neon indicators (two amber and one red) and a chart (located on a sticker attached to the device) that you match the neon indicators againts. It costs only a few dollars and is a very handy device to have to verify your receptacle is properly wired -- even a novice can do basic troubleshooting with this device. Unfortunately, they are only sold for 120V receptacles, so diagnosing 240V receptacles will require a volt meter and the experience to properly interpret the results. Whenever you move into a new home or apartment, it is a good idea to use this device to verify proper wiring on ALL your 120V receptacles and to have promptly repaired any that fail the test.
2) A poor or non-existent earth-ground (your ground rod). Ground rods can corrode and fail, ground wires connecting the ground rod to your main load center (breaker box) can become disconnected or your soil conditions may not be suitable for a single ground rod to get the job done. During drought periods, I had to drive 5 ten-foot copper-clad ground rods to achieve a sufficiently low resistance to ground due to the dry soil conditions. Code typically only requires a single 8-foot galvanized steel ground rod -- but sometimes it takes much more to achieve an adequate earth ground. Don't forget to also ground any metal plumbing (cast iron, lead or copper waste lines; copper or steel water lines, etc.) and gas lines.
3) A failure in your utility's neutral conductor and/or a failure to bond the earth ground (ground rod) to the neutral conductor in your main load center can result in an energized neutral or ground conductor. Failure to bond the neutral and ground really requires a thorough visual inspection of the ground wiring and a meter to check the resistance and voltage between neutral and ground to diagnose. Issue #2 can also come into play here if the ground rod is inadequate or not connected. A failure of the utility's neutral conductor results in a floating neutral whose voltage will fluctuate wildly as different 120V devices switch on and off throughout your home, and this unusual imbalance can overwhelm your ground rod's ability to absorb the imbalance. Typically, an intermittently failing neutral conductor will result in lots of flickering lighting and lighting that fluctuates between being dimmer than usual and being much brighter than usual as incandescent bulbs are very sensitive to voltage variations. You can also expect to see premature bulb failure and potential failure of 120V electronics whose power supplies were not designed for higher voltages (though many electronics these days are capable of operating from 85V to 240V and would not likely be harmed).
4) If this is limited to a single appliance, it can also be caused by an internal short in the appliance itself that has allowed the chasis to become energized. If the chasis is supposed to be grounded, then it should knock down the breaker, but if there is also an issue with the quality of, or the existence of, a proper ground connection then the chasis can remain dangerously energized.
As I said, this is by no means an exhaustive list and it often requires a good knowledgebase and experience to draw upon to diagnose such issues. On the positive side, once diagnosis is complete the actual repair is generally not outrageously expensive (e.g. drive a new ground rod, bond the earth-ground and neutral, replacing or repairing a damaged appliance, tightening a lose neutral conductor, etc.) though there are exceptions.
Let us know when you have pinned down the cause and don't be afraid to ask questions if you require further assistance.
HTH - Good luck!
