Network power supply

Discussion in 'General Discussion' started by cbrpete, Oct 21, 2010.

  1. cbrpete

    cbrpete

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    I`ve Just adopted a C bus install in a school & after connecting to the system to check current draw & burden, it informs me `maximim current exceeded`.To my horror,the system has 5000ma available on the bus.It`s actually only drawing 350ma because there are very few switches as most circuits are controlled via touchscreens.The system was installed in 2002 & appears to have been designed & programmed badly.It seems all the dimmers/relays have been speced with power supplies.
    Is this going to cause problems if a short circuit occurs.Chances are the cat 5 cable (which is not clipsal pink)would melt but would it cause damage to the cbus kit?
    Any ideas to how to reduce the current supply without tearing out half the modules & replacing with powerless ones?

    cheers

    Pete
     
    cbrpete, Oct 21, 2010
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  2. cbrpete

    Newman

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    The first thing I would check is whether or not the DIN Rail units really are the ones with or without power supplies. Toolkit has no way of knowing and relies on the installer specifying the correct catalogue numbers in the database. If the database was generated by just doing a network -> database transfer then Toolkit defaults to the cat#'s that include power supplies.

    If, after inspecting the units, you discover that you really do have 5000mA of power supplies on the network you have a problem. If that's true, I'd be surprised that the network works at all, so it's worth checking the physical units before jumping to conclusions. A sustained short circuit at the end of a long cable run could damage the cable under these circumstances.
     
    Newman, Oct 21, 2010
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  3. cbrpete

    cbrpete

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    That`s exactly how the database was generated.555 Ohms is showing on the impedence.I`ll double check what`s been installed.
    Thanks for that
    Pete
     
    cbrpete, Oct 22, 2010
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  4. cbrpete

    cona

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    cbrpete, I have the same issue on a project I've inherited and was wondering what you ended up doing about the oversupply of power to the network.

    Did you end up replacing the powered module for ones without a power supply to reduce it or did you find some other way?
     
    cona, Jul 22, 2020
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  5. cbrpete

    Ashley

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    As Newman suggested, the first step is to visually confirm that all the units toolkit thinks have power supplies really have them. If it is correct your options are to replace units with the non power supply versions (they have a P suffix for NO power supply), or to split the network into two using a network bridge.
     
    Ashley, Jul 22, 2020
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