Phase rotation meter what's the purpose
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  1. #1
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    Default Phase rotation meter what's the purpose

    Knowing nothing about them I thought they were to determine
    how to wire motor to get it to turn
    in the desired direction. But there
    must be more?
    Bob

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    No thats all they do...Phil

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    The usefulness may span a bit deeper. For example, one may be used to confirm that on site generation is connected to agree with grid power.

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    Quote Originally Posted by welderboy250 View Post
    The usefulness may span a bit deeper. For example, one may be used to confirm that on site generation is connected to agree with grid power.
    That would be a syncroscope.

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    When I worked at GE designing motor starter panels for 400 ton air conditioners, one not infrequent option with a phase orientation meter. Purpose was to ensure proper phase rotation before starting one of the machine, either on installation or after a power outage.

    Tom

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    The practical purpose is to ensure that motors that have to rotate correctly — do. It may not really matter which button makes the spindle spin forward but the coolant and/or hydraulic pumps do care and won’t build pressure if spun backwards.

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    Quote Originally Posted by digger doug View Post
    That would be a syncroscope.
    Syncroscope is not needed to confirm that a generator is connected for the same rotation as grid power at a distribution panel.

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    Generators: dc, do not require a synchroscope.

    Polyphase power as mentioned *does* use a synchroscope to tie two scources together.

    Phase rotation meter combined with an amp-clamp creates voluminous posts here.

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    In single phase wiring there are polarity test handheld gadgets. Good for a inspection.
    To prevent a shock from a threaded light bulb shield/socket.

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    I bought a inexpensive one years back when wiring passenger trains for HEP. Matching generators between multiple different locomotives and power cars to correct output rotation. I use it in the shop also for new equipment connections.

    Second most useful meter I ever owned, next to a really good multimeter.

    Sent from my rotary dial flip fone

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    Standard connection on a machine is clockwise turning field At least over here And on CNC machines I heard it too
    Also very handy for power outlets To give them all the same direction of rotation

    Peter

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    Maybe I need educated. Why is a syncroscope necessary over a rotation meter for connecting a genset wiring correctly?

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    I had to wire in the laser cutter at work. They said the phase direction mattered, and that it had to be clockwise, and it had to be known before attempting to power anything on.

    I had no meter, no electricians or electrical techs I knew had a meter (aside from ones used to measure it for motors from back EMF) and I couldn't even find a clear definition of what was clockwise and what was counterclockwise if I were to use my scope.

    In the end I set the E-stop circuit to lock out contactors and manually poked the contactor in for a hydraulic pump on the shuttle table. I was able to get that spinning the correct direction and then the whole machine worked.

    It would be cool if there was some standard for phase orientation.

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    There is a standard See my post 11
    Also if it is so critical the machine should have a phase monotering relay

    Peter

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    Quote Originally Posted by welderboy250 View Post
    Maybe I need educated. Why is a syncroscope necessary over a rotation meter for connecting a genset wiring correctly?

    it is required when generating power and to match the peak of the phases on the 60hertz cycle that goes positive then negative 60 times a second. if you add a negative power to a positive, it cancels each other out leaving zero energy potential.

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    Quote Originally Posted by BT Fabrication View Post
    it is required when generating power and to match the peak of the phases on the 60hertz cycle that goes positive then negative 60 times a second. if you add a negative power to a positive, it cancels each other out leaving zero energy potential.
    But more than that! Putting a generator on to the busbar out of sync will result in a very expensive bang as they attempt to get in sync. I’m sure that YouTube has some great videos of it. I haven’t done it myself yet..... still time! Have heard stories of generators being ripped off their mounts, cranks twisted and all sorts of havoc.

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    Quote Originally Posted by welderboy250 View Post
    The usefulness may span a bit deeper. For example, one may be used to confirm that on site generation is connected to agree with grid power.
    Quote Originally Posted by digger doug View Post
    That would be a syncroscope.
    Quote Originally Posted by welderboy250 View Post
    Syncroscope is not needed to confirm that a generator is connected for the same rotation as grid power at a distribution panel.
    Your lecturing me ?

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    Quote Originally Posted by wgnrr1 View Post
    ... Sent from my rotary dial flip fone
    Photos, please.

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    Quote Originally Posted by Peter from Holland View Post
    There is a standard See my post 11
    Also if it is so critical the machine should have a phase monotering relay

    Peter
    I suppose a standard that is commonly used such that I could take the red/black/blue and wire it to a machine or outlet and have it turn the correct way without measuring it or jogging motors is what I really want.

    I couldn't find anything I would be comfortable relying on during my quick google search so picked a different approach.

    100% agree that equipment should have phase rotation/phase loss detection. Only our laser chiller has that. Even our smart 40 hp Ingersoll Rand screw compressor doesn't notice if it's spinning backwards.

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    it does not rely on color It relays on the letters RS and T on the terminals or outlets

    Peter


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