Bidirectional watt-hour meters

quiquequique Posts: 252Solar Expert ✭✭
Im wondering if you guys know about these watt-hour meters...are they bi-directional?

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Im looking for the specs online.

Comments

  • waynefromnscanadawaynefromnscanada Posts: 3,009Solar Expert ✭✭✭✭
    Re: Bidirectional watt-hour meters

    It appears to be the older mechanical type. I have an old one that I used to use for monitoring freezer consumption etc, and it will run backwards. Tried it years ago when playing with turning an AC induction motor into a generator. When I turned on the motor, the meter would turn as expected, but when I applied mechanical power to the motor shaft to make it turn slightly faster than it "wanted" to go. the meter would stop, then as the motor was turned slightly faster, sure enough the meter would reverse. Looks like the same basic design meter.
  • quiquequique Posts: 252Solar Expert ✭✭
    Re: Bidirectional watt-hour meters

    I read online a while back, that some of them bring a ratchet which prevents reverse movement...
  • Blackcherry04Blackcherry04 Posts: 2,486Solar Expert ✭✭✭
    Re: Bidirectional watt-hour meters
    quique wrote: »
    I read online a while back, that some of them bring a ratchet which prevents reverse movement...
    Thats correct on some, the pawl falls into notches around the center of the wheel and makes it one directional. I have a smart meter now, but my old one was that way before I went grid tie. You might be able to see it on the center of the wheel or on the shaft end.
  • quiquequique Posts: 252Solar Expert ✭✭
    Re: Bidirectional watt-hour meters

    Is there any way to just remove that pawl?
  • Blackcherry04Blackcherry04 Posts: 2,486Solar Expert ✭✭✭
    Re: Bidirectional watt-hour meters
    quique wrote: »
    Is there any way to just remove that pawl?
    I guess you could if it has one. All the gearing is like a clock, if you were to disassemble it, you might have a hard time getting it back together. If you could just remove it without disassembly it might be easier.
  • peakbaggerpeakbagger Posts: 341Solar Expert ✭✭✭
    Re: Bidirectional watt-hour meters

    If you have the meters in hand why not just test them? Hook up a load with a meter wired in one direction see if it records and then hook up the load in the opposite direction and see which direction it records. If it records positive in one direction and negative in the other its bidirectional if its positive in both directions or only in one direction then they aren't
  • quiquequique Posts: 252Solar Expert ✭✭
    Re: Bidirectional watt-hour meters

    Yeah I know. But I'm still stuck with this meter and what if it isn't? So I was just thinking ahead to what to do if it isn't.
  • j2000j2000 Posts: 8Registered Users
    Re: Bidirectional watt-hour meters

    Hi all...iam from indonesia...
    Same like mine...
    My old watt hour meter is works well with grid tie...it can run backward....
    But unfortunately electric company change to new one direction only....
    So my grid tie system not working anymore....
    Very sad using my old off grid system....

    Regards

    Joel
  • inetdoginetdog Posts: 3,121Solar Expert ✭✭✭✭
    Re: Bidirectional watt-hour meters
    Thats correct on some, the pawl falls into notches around the center of the wheel and makes it one directional. I have a smart meter now, but my old one was that way before I went grid tie. You might be able to see it on the center of the wheel or on the shaft end.

    Actually, most of the mechanical versions will turn the dials in the same direction regardless of the direction the disk spins. Just blocking reverse motion of the dials is not enough to prevent fraud, since having the meter not move is almost as good as having it run backwards.
    The actual mechanism would be in the form of two overriding clutches arranged in opposite directions. One step harder to modify than just removing a pawl. :(
    SMA SB 3000, old BP panels.
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