[Prev][Next][Index][Thread]

Re: Ground current

  Original Poster: "Paul Marshall" <klugmann-at-hotmail-dot-com> 
 
 Bart,
   I have checked the amp meter its working fine. We have no aluminum 
 wire in the house and I get the ground current even when the power is 
 totally disconnected. The thing that blows my mind is the voltage. I 
 can't read it at all on the meter. Also I get no spark to ground from 
 ground neutral.
 
 What do you think ?
 paul m
 
Hi Paul,

I got a question to you. Are you using a DMM or a moving needle analog meter.

1.) In case of a DMM: Open it to make sure that all soldering connections are
okay. These meters have a very high (>10MOhms sometimes as high as 100MOhms)
internal resistance. I had a similar fault and it turned out that the meter
had some pretty bad internal soldering joints. After correcting these, the
meter ran perfectly (until I blew it up trying to measure some HV/HF
current... stupid I know...) These meters have also been known to pick up
stray currents floating around. If you go to the 10V AC scale and only connect
one pole to the live wire you will get a reading, even though the second lead
is not connected. This is the typical disadvantage of a super sensitive piece
of electronic equipment. Itīs sensitive to just about everything floating
around.

2.) In case you are using the old analog type: These meters can give you
faulty readings if you are encountering static electricity. Connect your meter
as usual and fog the scale with your breath. If the needle changes youīve got
static electricity problems, giving you the false reading.

It has to be this or a similar problem because if you canīt measure any
voltage (not even on a low scale) than you CANīT have a current flow. Use ohms
law and try to calc the voltage from the current you are reading and the
resistance you have, which has got to be very, very small (even if there is a
crappy conenction in the wiring somewhere).

Also, if you have no connections what so ever to the mains (no Neutral and no
Live) you canīt have a current flow. Or are you perhaps measuring a current
flow from your house ground to your RF ground? This would explain a reading on
the meter, but not in the AMP Range (uA or even mA, yes, but not Amps)

You should never connect N to ground after the electric companies do. If you
do this and have a three phase input in your house you will totally imbalance
your system, depending on how you load up each phase. This lets N wander away
from zero volts (measured to ground). If you short N to ground you are
removing this safety feature.

As a matter of fact we have so called FI circuit breakers over here that will
cut out as soon as you connect N and ground. This is called a fault current
switch and protects you from getting killed should you accidently touch Live
or Neutral.

let us know what you find,
Coiler greets from germany,
Reinhard