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Old 23-Jul-2019, 2:26 PM   #27
rabbit73
Retired A/V Tech
 
Join Date: Aug 2012
Location: S.E. VA
Posts: 2,518
Equipment Leakage Current

Quote:
Originally Posted by JoeAZ View Post
I cannot help but wonder the following: If grounding as above is not feasible or possible, would the following work???

Turn the power off to an outlet near the tv and/or cable inside the home.

Insert a grounding block or splitter if needed.

Run a 12 gauge or possibly a 10 gauge wire to the ground on the outlet.

Turn the power back on.

Probably not the best scenario but would if help discharge
static electricity????


That wouldn't be according to code, but it would connect the coax shield to the house electrical system ground if done properly.

However, it wouldn't connect the mast to the house electrical system ground to drain the static charge. The code requires two 10 gauge wires connected to the house electrical system ground, one for the coax shield using the grounding block and the other for the mast.

As a temporary (only) measure, I have connected the coax shield to the house ground using a spare 3-wire plug. Of course, the outlet must be a properly wired 3-wire receptacle. Using the plug avoids messing with the receptacle wiring.



I have had three close calls with electrical shock, so I think it is a good idea to connect the coax shield to the house electrical system ground, even for an indoor antenna.

The antenna coax is connected to AC operated equipment. All AC operated equipment has leakage current, even when operating properly. We can't feel it because it is below our level of perception. If the equipment has a 3-wire cord and is connected to a properly wired 3-wire receptacle, any leakage current will be shunted to ground.

If the equipment has a 2-wire power cord, any leakage current will go through you to ground. If there is a defect in the equipment, grounding the coax will protect you from shock.

When I was calibrating two converter boxes, I felt a tingle when I touched the coax shield and a grounded metal strip on the counter. The antenna system had not been grounded for the tests.



I wanted to find out why I was being shocked, so I made some measurements with my Simpson 229 Leakage Current Tester. The meter showed almost 200 ľA (200 microamperes or 0.2 mA) of leakage current.



When I grounded the coax with the plug shown above, the leakage current went to zero.

Details of tests in attachment.
Attached Images
File Type: jpg Leakage Current Tests2.jpg (229.9 KB, 45 views)
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Last edited by rabbit73; 24-Jul-2019 at 6:41 PM.
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