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  1. #1
    Join Date
    Dec 2005
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    Control LAN running between building

    I have this church with CSI controller 7793. Its LAN has problem when we extend to the buildings they just purchased. And we used the B channel. This LAN is running under the metal walk-way about 300ft.

    I checked every node of the controllers on this channel B per specification as of channel A.

    Problem: Once and a while when lightening storm, one of the controller will crashed and corrupted the whole LAN on B channel. The church has electrician installed surge protector at the main power and it helped the computers throughout the church BUT this controller LAN.

    I read that there are protector against LAN line running between buildings in the Kele catalog. I wonder you guys have any inputs.

    Thanks in advance

  2. #2
    Join Date
    Jul 2012
    Location
    Northern NY
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    I am not familiar with that controller or the protocol but if it is RS-485 there are some typical rules when you connect buildings.

    If 2 buildings are connected and they have different power feeds the grounds and neutrals may not be at the same potential and this can lead to strange communication problems because the ground is used as a zero reference in most controllers for RS-485

    A rule of thumb is to have optical isolation on an RS-485 network as it leaves or enters a building. This would mean an isolator in each building and 2 in any place where it enters that heads to another building.

    To keep costs down you could start with just one to separate the 2 buildings electrically and see if that helps.

    I have had problems with communications between buildings in the past and had optical isolation and this protected my whole network from dying and I only lost the remote panel. In my case is was the cable being submerged in water in the underground conduit and it was causing some leaking between wires. Replaced the cable and kept it dry and everything was fine.

    -Jeremy

  3. #3
    Join Date
    Jun 2009
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    StL, MO
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    572
    I'd go wireless if possible.
    UA LU 562

  4. #4
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    Mar 2005
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    Agreed w/above statements, but also I would look into a UPS not surge protection alone. I've had good luck w/the sola for other controllers and have used a bunch, don't recall what the guys used on the INET controllers.

    http://www.kele.com/power-supplies/s...du-series.aspx

    http://208.69.45.150/casefiles/3904/...Inter-Spec.pdf

    http://www.bb-elec.com/product_famil...e=Sub&Trail=10

    http://store.moxa.com/a/product/tcc-...d=M20090312611

    Maybe TP will chime in.
    "How it can be considered "Open" is beyond me. Calling it "voyeur-ed" would be more accurate." pka LeroyMac, SkyIsBlue, fka Freddy-B, Mongo, IndyBlue
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  5. #5
    Join Date
    Dec 2006
    Location
    Hartford, Connecticut
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    Could be a few different things causing it.

    Just a few basic comments;

    1) Are you using low cap 22 or 24 gauge wire on the B Channel?

    2) Are the shields bonded continuous throughout the B Channel at each MR/ASC and not terminated on the controller terminal blocks?

    3) Does the shield drain have an earth ground on one end?

    4) Is the 24 volt power grounded for the MR’s/ASC’s on the B Channel? Those are all half wave devices.

    A surge arrestor would help with any transient voltage. There was a CSI model SA-1, however I do not believe Schneider Electric makes those any more. Like crab master I use the SOLA and the Kele DTK and HSP series and have had good results with them.

  6. #6
    Join Date
    Aug 2009
    Posts
    31
    Quote Originally Posted by just_opinion View Post
    I read that there are protector against LAN line running between buildings in the Kele catalog.
    First understand what that 'whole house' protector did. No protector does protection. It simply connected incoming surges to earth ground. The earth ground did that protection.

    The concept is simple. Any wire (overhead or underground) that enters a structure must first connect low impedance to earth. The 'whole house' protector solved it on AC electric. Existing telco 'whole house' protector (always installed for free by the telco) took care of those wires. But you still have that LAN.

    Second, each structure must have its own single point ground. Any wire between both structures must first enter (leave) by connecting low impedance to that earth ground. If this is Ethernet, then many good protectors exist. How to separate the good ones from useless ones? Good ones will have a ground wire that must connection to earth ground (not wall receptacle safety ground). The single point earth ground. The same earthing electrode also used by that building's AC electric and telephone.

    If this grounding rule is not followed, then a direct strike to one building is also a direct strike to connected electronics in the other building. Worry little about the protector. Worry most about what actually is doing protection - single point earth ground.

    Third, referenced was the term 'low impedance'. A wire to earth has excessive impedance if it has sharp bends, splices, is inside metallic conduit, or is too long (ie 'more than 10 feet'). Wire thickness is less relevant. Wire length is critical.

    Both a connection to and quality of earth ground should have most of your attention. Unfortunately these relevant electrical concepts are too often misunderstood by electricians. For example, an earth ground must both meet and also exceed code. The electrician would understand code. But would not understand why that wire must have no sharp bends and be less than 10 feet. Electrician would understand resistance. But only better ones have learned about impedance.

    Some possible protectors (don't know if all URLs are still valid):
    http://www.protectiongroup.com/Prote...3.pdf?ext=.pdf (Transtector TSJ series)
    http://www.ditekcorp.com/product-details.asp?ProdKey=59 (Ditek DTK-MRJ45C5E)
    http://www.digitaltele.com/category.aspx?categoryID=107
    http://www.hyperlinktech.com/web/dat...protectors.php
    http://www.polyphaser.com/datasheets/NX4-60.pdf
    http://www.l-com.com/item.aspx?id=22335
    http://www.transtector.com/admin/Dat...s/1400-624.pdf

  7. #7
    Join Date
    Nov 2006
    Location
    SE Wisconsin
    Posts
    302
    Edco makes a gas tube isolation device that may provide some protection. I'm not at home where the laptop is with the info but I can look it up later. I believe the rating for the isolation cartridge is about 7.5 vdc.

  8. #8
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    Dec 2005
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    Quote Originally Posted by twisted pair View Post
    Could be a few different things causing it.

    Just a few basic comments;

    1) Are you using low cap 22 or 24 gauge wire on the B Channel?

    2) Are the shields bonded continuous throughout the B Channel at each MR/ASC and not terminated on the controller terminal blocks?

    3) Does the shield drain have an earth ground on one end?

    4) Is the 24 volt power grounded for the MR’s/ASC’s on the B Channel? Those are all half wave devices.

    A surge arrestor would help with any transient voltage. There was a CSI model SA-1, however I do not believe Schneider Electric makes those any more. Like crab master I use the SOLA and the Kele DTK and HSP series and have had good results with them.
    The answers

    1) 22
    2) Yes, just like the A channel
    3) Yes, just like A channel at the main 7793 controller. Its earth ground is dedicated with a single rod with NO other devices but this 7793 ONLY.
    4) Oh yes they are.
    I also use a voltage surge protector at each MR http://www.kele.com/power-monitoring...1-5ke56ca.aspx

    I know there is a surge of the LAN signal above its tolerance. That is why its own LAN over-voltage protector blows and shunt its signal to ground and therefore corrupt the whole LAN line. It is a easy fix. But it is annoying as hell. And finding the bad one is a pain too

    This site's branch with channel B has 3 buildings - 7, 8, and 9. But building 7 and 8 have the same electrical meter. And building 9 has its own meter and different transfomer.

    I think Jeremy may have something for me to build on here with his 2nd paragraph

    Quote Originally Posted by kc2dnw View Post
    ...

    If 2 buildings are connected and they have different power feeds the grounds and neutrals may not be at the same potential and this can lead to strange communication problems because the ground is used as a zero reference in most controllers for RS-485
    ...
    -Jeremy
    Now I think Jeremy MAY make sense. Another church had its UC crashed due to a horrific lightening strike. So I change them all to MR and combine with other building with the existing 7793 on channel B. SINCE then, I have weird problem such as ---- MR just went dead (no talking to 7793); MR won't function even though the MCI (computer) shows all DO outputs are ON. But the controller's DO outputs are not ON at all. Cycle the power to that controller and it functions fine. AND I think (THINK) they have 2 different electrical meter (power source)

    Thanks y'all

  9. #9
    Join Date
    Dec 2005
    Posts
    1,828
    Twisted Pair,
    Another problem with this site. This site has only MR88R and MR55R
    I use the AO as my setpoint. And it is defined as INTERNAL point with 0 as low limit and 100 as high limit. This setpoint is NEVER changed by the operator/user.
    But once and awhile I see it turn RED -- alarm mode.

    I just click page-acknowlege and it turn blue (normal) and stay like that for day(s) and may be 2-3 weeks.

    But how can an INTERNAL defined point goes alarm even though its values never goes out of its limit range.

    Not one AO but all AO that I use as INTERNAL point turn red (alarm).
    I can turn the power off to that controller and they NEVER turn red (alarm)

    Any idea ?

  10. #10
    Join Date
    Aug 2009
    Posts
    31
    Quote Originally Posted by just_opinion View Post
    But how can an INTERNAL defined point goes alarm even though its values never goes out of its limit range.
    You can have 2 volts difference between two wires. And both wires are also at 800 volts.

    kc2dnw said why. I said similar using a term 'single point earth ground'. If you do not do as was posted, then even 1000 of those MOV and transorb protectors are useless. This is not about feelings. This is the engineer who does this stuff. Forget what you feel might be the problem. What is in that post must exist no matter what.

  11. #11
    Join Date
    Nov 2006
    Location
    SE Wisconsin
    Posts
    302
    Sounds like it's time to invest in some 527-NPR's and additional viewcons, one for each building, in my opinion.

  12. #12
    Join Date
    Mar 2005
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    Pacific Time Zone
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    These were at a pretty decent rate - don't know about lately.

    PACKAGE of 3 TAC Xenta 527
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    BIG Government = More Dependents
    "Any 'standard' would be great if it didn't get bastardised by corporate self interest." MatrixTransform
    http://threedevilskennel.com/ - not my website.
    Versatile Hunting Dog Federation - www.vhdf.org/


  13. #13
    Join Date
    Dec 2006
    Location
    Hartford, Connecticut
    Posts
    442
    Quote Originally Posted by just_opinion View Post
    Twisted Pair,
    Another problem with this site. This site has only MR88R and MR55R
    I use the AO as my setpoint. And it is defined as INTERNAL point with 0 as low limit and 100 as high limit. This setpoint is NEVER changed by the operator/user.
    But once and awhile I see it turn RED -- alarm mode.

    I just click page-acknowlege and it turn blue (normal) and stay like that for day(s) and may be 2-3 weeks.

    But how can an INTERNAL defined point goes alarm even though its values never goes out of its limit range.

    Not one AO but all AO that I use as INTERNAL point turn red (alarm).
    I can turn the power off to that controller and they NEVER turn red (alarm)

    Any idea ?

    I cannot think of anything that would cause that. I will have to give it some more thought. Is there anything attached to those points like an event or another point extension?

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