adccommunitymod (AutomationDirect) asked a question.
Created Date: July 07,2008
Created By: DuctSoup
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I'm doing an interface to a (really) big power supply using 0/4-20mA current loops. One of the transmitters is an Omega CCT-01-0/650V signal conditioner. Looking at the documentation, a couple things are unclear. NAICT the most similar wiring examples are shown on page 2-82 of the DL05/06 Option Module manual. Please forgive the following analog noob questions ... 1. Best practice is typically to ground the shield at the source. This page has a note that says don't ground both ends which also makes sense to me but, the diagram shows all the shields grounded connected to COM. Can anyone clarify best practice? EMI, HF and harmonics are known issues with this power supply so I'd like to get it right the first time. 2. The first note says that all current loops should be fused but only the second actually shows a fuse. Did someone just run out of space when drawing the diagram? 3. The documentation on the Omega device (which is in no way similar to the one from Doctor Who - Remembrance of the Daleks) is sparse and simply indicates "+ " and "- " for the output current loop. Can anyone offer any information on the correct way to wire these two devices? TIA, Craig
Created Date: July 08,2008
Created by: FACTSTech
"NAICT the most similar wiring examples are shown on page 2-82 of the DL05/06 Option Module manual. " The module can be found here http://www.automationdirect.com/static/manuals/d0optionsm/ch4.pdf
When using the Omega signal conditioner it would be best to ground the shield to the shortest path to ground this would be the module COM. If the transmitter is mounted on a plastic tank or similar, then grounding at the source is not practical.
As for the missing fuses in the "wiring examples " this is an example as you have stated. We felt it more important to show the different types of transmitters than to clutter up the wiring examples with fuses, hence note 1.
"simply indicates "+ " and "- " for the output current loop " wire + to CH 1 and - to COM. Make sure that you ground the 24V power supply and the PLC "G and LG " terminals to the panel ground stud.
Created Date: July 08,2008
Created by: DuctSoup
So basically it's pretty straightforward and I'm seriously over thinking this bit. Good deal.
Thanks for the info, Craig
Created Date: July 07,2008
Created by: DuctSoup
I'm doing an interface to a (really) big power supply using 0/4-20mA current loops. One of the transmitters is an Omega CCT-01-0/650V signal conditioner. Looking at the documentation, a couple things are unclear. NAICT the most similar wiring examples are shown on page 2-82 of the DL05/06 Option Module manual. Please forgive the following analog noob questions ...
1. Best practice is typically to ground the shield at the source. This page has a note that says don't ground both ends which also makes sense to me but, the diagram shows all the shields grounded connected to COM. Can anyone clarify best practice? EMI, HF and harmonics are known issues with this power supply so I'd like to get it right the first time.
2. The first note says that all current loops should be fused but only the second actually shows a fuse. Did someone just run out of space when drawing the diagram?
3. The documentation on the Omega device (which is in no way similar to the one from Doctor Who - Remembrance of the Daleks) is sparse and simply indicates "+ " and "- " for the output current loop. Can anyone offer any information on the correct way to wire these two devices?
TIA, Craig