On Fri, Mar 16, 2012 at 09:04:35AM -0400, Troy Settle wrote: > Ok, so to keep to code, we have a GFCI outlet for most of our towers. > One of them tripped last night, causing me to have to put on some 80 > miles just to push a button (yes, it could have been much worse). > > Is there anything to prevent stupid outages like this from happening > without violating code?
The tower at my house has gear plugged into the GFCI outlet nearby. It seems to trip once every three or four months. I've done some looking online for possible causes and the most likely sounding explanation was that the equipment on the tower is grounded to the tower and the tower ground system is not connected to the electrical service ground. The AC panel is grounded to the electrical service ground rod on the other end of the house. I did not run the 80 feet of ground wire to connect the tower ground system to the electrical service ground rod. I would have to break up some patio area to reach reach the electrical service ground rod. The postulation on the web forum was that in cases such as that, there could be a very small difference in ground potential between the two sets of grounds. They suggested that the proper solution would be to correctly connect the electrical service ground to the tower ground. Under certain circumstances the ground potential difference could be increasing just enough to cause the GFCI to sense a fault. The last three times it happenned it was at around 8 AM which is about when the tower end of the house gets fully bathed in the first morning sunlight. The service ground area is still fully shaded for another 3 hours. My best guess is that the temperature change / difference is causing ground potential variations. I have a 3/4 inch copper, cold water, pipe running from one end of the house to the other which I could use to connect the two ground systems, but I haven't done the research to figure out if that is safe. The cold water pipe is plastic before it makes ground contact. So, the pipe itself is not a good place to find an electrical ground. -- Scott Lambert KC5MLE Unix SysAdmin [email protected] _______________________________________________ Wireless mailing list [email protected] http://lists.wispa.org/mailman/listinfo/wireless
