Positive Amps, Negative Watts

[mick1988]

It's not on every sensor, but a few of my circuits have positive amps, but negative watts. Ive verified that the CTs are on the correct way. CT5 and CT6 are wired the exact same and CT5 is working correctly, but CT6 shows negative watts.

12C CT5 Amps | 9.52 A |  
12C CT5 Watts | 1075.88 W |  
12C CT6 Amps | 2.64 A |  
12C CT6 Watts | -287.50 W

    phase_b:
      current:
        name: ${disp_name} CT5 Amps
        id: ct5Amps
      power:
        name: ${disp_name} CT5 Watts
        id: ct5Watts
      gain_voltage: ${voltage_cal}
      gain_ct: ${current_cal}
    phase_c:
      current:
        name: ${disp_name} CT6 Amps
        id: ct6Amps
      power:
        name: ${disp_name} CT6 Watts
        id: ct6Watts
      gain_voltage: ${voltage_cal}
      gain_ct: ${current_cal}

I can "fix" it by adding:

        filters:
          - lambda: return abs(x);

But I'd like to know why some calculate correctly and others do not. Thanks!

[CircuitSetup]

Try turning the CT around on the wire 😉

[mick1988]

The arrow is verified the correct way and the amps are positive, however, I didn't just try flipping around the CT anyway. Easy enough to give that a shot.

[mick1988]

Well, always try the easy stuff first, flipping it worked. Can someone give me a quick lesson on why some circuits need the CT arrow pointing away from the breaker and some need it towards the breaker? Is it something to do with how the two phases work? CT5 is on Phase B, and CT6 is on Phase A. Some of the CTs are a tight fit, so it'd be nice to have an idea of which way it should be before installing it.

[CircuitSetup]

Is it something to do with how the two phases work? CT5 is on Phase B, and CT6 is on Phase A.

Yes! If the voltage transformer is plugged into Phase A, the CTs on that phase will have arrows pointing towards the breaker, and CTs on Phase B will be away from the breaker. This is because the 2 phases are 180 degrees out from each other.

If you were to measure voltages from both phases then all of the CTs would have arrows pointing towards the breakers, assuming the CTs are on the same phase as the voltage transformers.

[mick1988]

Awesome, that makes sense. Thanks for answering

[wwk-github]

@CircuitSetup in Poland we have 3 phase system so there is a 120 degrees difference between each. Is the board capable to deal with this?

[CircuitSetup]

Yes, but you need at least 1 add-on board. See here.

[gustavalberius]

@CircuitSetup I'm in Sweden so I also have a 3 phase system. Do I have to have three transformers or can I take some sort of shortcut if I'm willing to sacrifice some accuracy?
I have an outlet by the central in which it's easy to put one transformer. If I need three I need to dig deeper into the central...

[caladeira]

I'm in Portugal and I also have a 3-phase system. For space problems, my suggestion is to use 3 small PCB transformers: phase 1 - 9vac 6VA, phase 2 - 3VA, phase 3 - 3VA I've calibrated voltage in the software and they have been working very well for about one year.

…

On Sat, Nov 5, 2022 at 6:07 PM gustavalberius ***@***.***> wrote: @CircuitSetup <https://github.com/CircuitSetup> I'm in Sweden so I also have a 3 phase system. Do I *have* to have three transformers or can I take some sort of shortcut if I'm willing to sacrifice some accuracy? I have an outlet by the central in which it's easy to put one transformer. If I need three I need to dig deeper into the central... — Reply to this email directly, view it on GitHub <#87 (reply in thread)>, or unsubscribe <https://github.com/notifications/unsubscribe-auth/ACNMNO5HXSKYCSIJ562Y36DWG2O4ZANCNFSM5OUS3BYQ> . You are receiving this because you are subscribed to this thread.Message ID: <CircuitSetup/Expandable-6-Channel-ESP32-Energy-Meter/repo-discussions/87/comments/4065161 @github.com>

[gustavalberius]

That's an excellent solution! Can you give more details?