|
|
| Author |
Message |
easy.wei@gmail.com
science forum beginner
Joined: 04 May 2006
Posts: 3
|
 Posted: Wed Jul 12, 2006 3:35 am Post subject:
Signal earthing to control system
|
|
|
to combine or not to combine , this is a problem.
In one project , DCS vendor Honeywell requested that the
signal earth of DCS system should be seperated from plant electrical
earthing system. They said electrical earth maybe disturb instrument
signals to DCS. But our electrical engineer suggested that combined
earth was better and seperated earth may make system worse.
Anyone has experience of control system earthing? |
|
| Back to top |
|
 |
Jerry Avins
science forum Guru
Joined: 03 May 2005
Posts: 534
|
| Posted: Wed Jul 12, 2006 3:54 am Post subject:
Re: Signal earthing to control system
|
|
|
easy.wei@gmail.com wrote:
| Quote: | to combine or not to combine , this is a problem.
In one project , DCS vendor Honeywell requested that the
signal earth of DCS system should be seperated from plant electrical
earthing system. They said electrical earth maybe disturb instrument
signals to DCS. But our electrical engineer suggested that combined
earth was better and seperated earth may make system worse.
Anyone has experience of control system earthing?
|
Single-point earthing avoids ground loops (should that be earth loops? I
get dizzy thinking about that) The earthing leads should carry no
current common to the instruments and the power equipment. In sever
cases, instrument amplifiers (or isolation amplifiers) may be helpful.
Jerry
--
Engineering is the art of making what you want from things you can get.
ŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻ |
|
| Back to top |
|
|
fulliautomatix
science forum beginner
Joined: 01 May 2005
Posts: 34
|
| Posted: Wed Jul 12, 2006 12:17 pm Post subject:
Re: Signal earthing to control system
|
|
|
easy.wei@gmail.com wrote:
| Quote: | to combine or not to combine , this is a problem.
In one project , DCS vendor Honeywell requested that the
signal earth of DCS system should be seperated from plant electrical
earthing system. They said electrical earth maybe disturb instrument
signals to DCS. But our electrical engineer suggested that combined
earth was better and seperated earth may make system worse.
Anyone has experience of control system earthing?
|
Mine are always earthed to one point, and if several power supplies are
used I tie the neutrals together
But my DCS's are cobbled together expansions and bits added to machines
rather than something designed from the ground up |
|
| Back to top |
|
|
Google
|
|
| Back to top |
|
|
|
|
The time now is Sun Nov 23, 2008 6:04 pm | All times are GMT
|
|
Credit Cards | Advertising | Tile Forums | Power Rangers | Bad Credit Mortgages
|
|
Copyright © 2004-2005 DeniX Solutions SRL
|
|
Other DeniX Solutions sites:
Electronics forum |
Medicine forum |
Unix/Linux blog |
Unix/Linux documentation |
Unix/Linux forums
|
Powered by phpBB © 2001, 2005 phpBB Group
|
|
FAQ
Search
Memberlist
Usergroups
Register
Profile
Log in to check your private messages
Log in
Forum index
»
Science and Technology
»
Engineering
»
Control
