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Datalogger for 3-phase

  • 25-01-2008 11:39am
    #1
    10-10-20
    Registered Users, Registered Users 2 Posts: 7,411 ✭✭✭


    Hi guys,

    Can anybody recommend a monitor or datalogger for a three phase supply.
    I have a lab which is running off a 300A (3x 100A breakers) supply and the usage is too high presently, we are consuming 280A.
    I want to encourage more responsible usage of the equipment in the lab and the first step is to be able to measure the current consumption and chart it on a monthly basis.

    Of course I'm not going to fit this myself, but guidance would be be appreciated in terms of what others may have implemented.

    Thanks,
    10-10-20


Comments

  • #2
    10-10-20
    Registered Users, Registered Users 2 Posts: 7,411 ✭✭✭10-10-20


    I should specify this further...
    I am looking for a panel mounted monitor, but not hand-held. It could be a simple digital display per phase, or a combined unit.

    I had a look at Radionics but the prices for the three phase units are €3,000+.
    I'm looking to implement this for less than €700.


  • #3
    DublinDilbert
    Registered Users, Registered Users 2 Posts: 5,390 ✭✭✭DublinDilbert


    10-10-20 wrote: »
    I should specify this further...
    I am looking for a panel mounted monitor, but not hand-held. It could be a simple digital display per phase, or a combined unit.

    I had a look at Radionics but the prices for the three phase units are €3,000+.
    I'm looking to implement this for less than €700.

    What about some sort of Hall effect current monitor on each phase?

    Does it need to be a 3 phase device?

    As they are hall effect they don't as such need to be connected to the system, just need one around each of the 3 phase bus bars. Then 3 displays showing the current in each phase.

    Also i'm guessing your trying to make gross measurements, eg +/- a few amps won't make a huge difference. If you look up "Hall effect LEM devices" you should be able to get something to do the trick.

    Maybe then some analogue panel meters on the front door of the main panel.

    I wouldn't use a traditional Current transformer, something funny happens when you open circuit the secondary winding, from memory its likely to blow on you....


  • #4
    10-10-20
    Registered Users, Registered Users 2 Posts: 7,411 ✭✭✭10-10-20


    Hi DublinDilbert,
    The supply is installed and running, so it's three-phase. Anyhow, you couldn't put all of this load in a single phase!
    Much in all as I'd love to, I can't go down the route of making my own sensors as devices attached to the incoming mains must be certified according to the facilities guys.


  • #5
    Stoner
    Registered Users, Registered Users 2 Posts: 10,952 ✭✭✭✭Stoner


    you could rent a VIPs meter from someone like Jackson Switchgear, this would watch each phase for you and report as desired


  • #6
    DublinDilbert
    Registered Users, Registered Users 2 Posts: 5,390 ✭✭✭DublinDilbert


    10-10-20 wrote: »
    Hi DublinDilbert,
    The supply is installed and running, so it's three-phase. Anyhow, you couldn't put all of this load in a single phase!
    Much in all as I'd love to, I can't go down the route of making my own sensors as devices attached to the incoming mains must be certified according to the facilities guys.

    You misunderstood me, I never suggested putting it all onto a signal phase...

    I suggesting leaving it as is, but metering the current in each phase separately. IE you don't need a 3 phase data logger, you need 3 single phased ones ;)

    If you could get LEM transducers that give 1mV / Amp all you would need to do is pop a mV meter on to their output and you get a reading out...


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  • #7
    dingding
    Registered Users, Registered Users 2 Posts: 4,937 ✭✭✭dingding


    Could you monitor one phase, connect it to a meter giving a total meeting, I would assume that the loading would be the same on each phase.


  • #8
    10-10-20
    Registered Users, Registered Users 2 Posts: 7,411 ✭✭✭10-10-20


    dingding wrote: »
    Could you monitor one phase, connect it to a meter giving a total meeting, I would assume that the loading would be the same on each phase.

    No, loading is not equal.
    Presently 100A, 80A, 100A!


  • #9
    10-10-20
    Registered Users, Registered Users 2 Posts: 7,411 ✭✭✭10-10-20


    DublinDilbert wrote: »
    You misunderstood me, I never suggested putting it all onto a signal phase...

    I suggesting leaving it as is, but metering the current in each phase separately. IE you don't need a 3 phase data logger, you need 3 single phased ones ;)

    If you could get LEM transducers that give 1mV / Amp all you would need to do is pop a mV meter on to their output and you get a reading out...

    They look to be a possible solution. I won't be 'attaching' to the supply. Radionics supply them also. I just need to work out whether Facilities will allow me to install them.
    I'll have to get the electrician to down the supply, but that's not too hard.


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