Basic speaker cable question

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academia50

academia50

Member
Joined 2013
PRR said:
You mean, to a dirt-rod?

I have. The bulb is dim.

This with a nominal 120V 0.5A (60W) lamp and 7 feet of rod under my septic field; and the power company dirt-rod (2 8') on the far side of the field.

My summary data suggests around 120 Ohms from a full size dirt-rod to another rod on the same land, implying 60 Ohms from one rod to an imaginary "true earth".

My 60W lamp is nominally 120V/0.5A= 240 Ohms, so 60-120 Ohms in series makes it dim. (And a dim bulb is a lower resistance, so I was getting like half of line voltage.)

This incidentally means I can NOT blow a breaker with "earth current" literally through dirt. Three 60 Ohm rods is 20 Ohms, marginally under the NEC goal of 25 Ohms, but 120V/20r is only 5 Amps, and my smallest breakers are 15A.

Things CAN be different on the damp salty coast of Florida.
Click to expand...

It all depends on the conductivity of the soil. It's a test I did many times (before the differential switches were invented) and it always worked. Surely this protector (great invention) will be activated, so I will disconnect it and I will do it again. Here the lamp lights up in all its luminous intensity.
Here we have 220 volts / 50 Hz. It is a very humid climate and also live near the Rio de la Plata. And there is a very old power plant (which was fueled by coal, then gas) in Puerto Nuevo, Buenos Aires. They took the neutral and connected it to a huge copper plate submerged in the muddy bottom of the River. I have a javelin connected to the entire neutral installation of the house, so I'll use it to repeat the experiment.
 
techtool

techtool

Member
Joined 2012
For what it's worth, there is a type of residential power distribution system called SWER, which stands for Single Wire Earth Return. For 20 years lived in an old neighborhood with this system. A single 2000 volt wire fed one end of the pole transformer(s) primary and the other end went to a ground rod. So the return path back to the power station was through the ground/dirt/mud/water for several miles. The regulation isn't good and our line voltage would be anywhere from 102 to 125V. I couldn't believe such an archaic system is still in use in metropolitan New Jersey in 2019. It was probably installed by Westinghouse himself and hasn't been upgraded since. I am an EE who went to college in the 70's and this wasn't covered in any of our power courses. I learned about it by living with it.
 
M

MAAC0

Member
Joined 2010
The best cable is the one made from unobtanium material. You can't make it. You can't listen to it. It works best when You really need moments of silence. I believe I have somewhere lying around old headphones with rare metal ?? magnets. There are many companies who want Your money. Trust me !!
 
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