Clean, protective and instrument earth
Clean, protective and instrument earth
(OP)
Can anyone explain the difference between the above?
In the main the diffrence between and requirement for both a clean earth and an instrument earth.
Thx
In the main the diffrence between and requirement for both a clean earth and an instrument earth.
Thx





RE: Clean, protective and instrument earth
The instrumentation system typically has signals of 4 to 20 mA DC (or, 1-5V DC, etc.) and cannot take kilo-amperes of current. That is why the instrument earth (for the instrumentation SIGNALS) is separate and isolated from the electrical earth.
A clean earth is the combination of a secure connection to the earth and a very low earth resistance (using a battery of earth pits, if required) - so that the resistance to earth is very low (typically of the order of 1 ohm). This is required so that the potential of the instrumentation system with respect to the earth is very small, for any current to earth.
RE: Clean, protective and instrument earth
So as somebody else has said the term clean earth and instrument earth are interchangeable?
If so are these the points generally used for barrier earths and screen termination?
RE: Clean, protective and instrument earth
Gunnar Englund
www.gke.org
RE: Clean, protective and instrument earth
sorry about that I saw related stuff in the other electrical / electronic group too.
Not sure how to put a link in from here..
RE: Clean, protective and instrument earth
We are using JUST for INSTRUMENTATION:
1. Protective ground (connecting instruments base to the ground Electrode.
2. Signal Ground - Connecting all the instruments ground
3. Shielded Ground - Connecting only the analog wires screens.
Each ground has it own grounding electrode. The electrical equipment has a different grounding system.