grounding 1

[lugods]

what are the disadvantace if you convine electronic equipment grounding to power grounding?



thank for sharing your knowledge.


bernardino

 

[itsmoked]

There are usually few disadvantages to connecting instrument grounds to power grounds.

Keith Cress
Flamin Systems, Inc.-

http://www.flaminsystems.com

 

[ruggedscot]

Fault currents is one major disadvantage - you get current paths generating some voltages that can mean destruction to some sensitive electronic equipment.

Keep those electronic grounds seperate from your power grounds!

 

[davidbeach]

You can't, per code, keep them separate. You can limit the it to a single point of connection, but all grounds must be connected together.

 

[alehman]

ruggedscot - separate grounds is a common misconception that was promulgated by the electronics industry a number of years ago. It is a dangerous practice and as David said, a violation of all known electrical codes in most cases. With proper engineering, grounding systems can be combined without interference or risk to electronic equipment.

 

[peebee]

What davidbeach and alehman said. Ruggedscot, we gotta send you back to grounding school.

 

[itsmoked]

Or you're GROUNDED!

Keith Cress
Flamin Systems, Inc.-

http://www.flaminsystems.com

 

[ruggedscot]

Grounding in med theatres and in micro electronics tend to have seperate grounds. They also use isolated power systems with earth leakage control. As I said any fault current in some systems could wreck havoc with electronics so they try to maintain some form of isolation. Grounding also tends to be very very good to ensure that the resitive paths are kept as low as possible.

 

[waross]

If you have two seperate grounding systems, you can expect some voltages to show up unexpectedly. It is the seperate grounds or improper grounding that causes those " voltages that can mean destruction to some sensitive electronic equipment."
The first purpose of grounding is for the safety of persons and equipment. Consider a plant in an area known for poor grounding conditions. A ground fault on a 2400 volt circuit or a 480 volt circuit may result in the plant ground potential rising above "true" ground potential. In this case you and your equipment are a lot safer if you all stay at plant ground potential rather than having one grounding system at a different voltage than the other. Step potentials and touch potentials are life threatening voltages that develop on surfaces under fault conditions. Proper grounding practice and proper interconnection of grounds reduces or eliminates these hazards. Take a look at the membership of the NEC or CEC code committees to get an appreciation of the backgrounds, experience and work environments of the people who write the codes. They demand that grounding systems be interconnected. This ensures the same potential, and that is a lot safer all around than having a piece of electronic equipment on one ground system sitting next to a piece of equipment on a power ground that has just risen in potential due to a fault. You don't want to be touching both pieces of equipment in such a case. The sensitive electronics may not like it either.
respectfully

 

[ruggedscot]

Okay Im grounded.....

Maybe looking at older systems and these tend to change with the wind.

Rugged