Current <-> Power Not Making Sense

[io_guy]

Just hooking my GEM back up in my new place. Updated to firmware 5.13 and things are communicating fine.

I have channel 4 that's not making sense. The power is likely in the right ballpark, the current as you can see makes no sense. 2 Micro-80s used and the channel configured for them (2-pole circuit):

Screenshot 2020-11-18 194040.jpg (40.75 KiB) Viewed 1706 times

[io_guy]

And now I have a second one doing it. Single CT Micro-40 (Channel 7):

Screenshot 2020-11-18 200338.jpg (42.56 KiB) Viewed 1703 times

[Teken]

Some things to consider and validate in the installation / settings.

- Type B: Are the micro 80's wired in a Type B configuration as outlined in the installation manual page - 21 / 22
- CT Settings: Insure the settings are correct for the Micro 80's in the GEM. For good measure change the value and save and go back go the original value and save.
- Wiring: Insure the CT is inserted all the way inside of the terminal block.
- GEM: Confirm that channel isn't set to double for a 240 VAC circuit. Doubling is intended to be used for a single CT in place where a person wants to monitor a 240 VAC circuit but only has a single CT present.

- Validation Load: I would quickly find a known load from below 100 watts, mid range 500 watt, and high load say 1500 - 1800 watts. Using anything from an incandescent 60 / 100 watt bulb, hair dryer which can output 500 - 850 watts, to a ceramic heater of 1000 ~ 1800 watts. Move the CT to that circuit to be monitored and see if the correct wattage is seen from light bulb, hair dryer, ceramic heater.

PT: Using a reliable RMS DMM measure the PT and adjust the GEM to match. Never invert the PT once its been installed and deployed as this will cause issues in the system.

Constant Current: Insure this setting was not inadvertently changed . . .

Please post up what all of the settings and wiring looks like for your installation for the GEM.

[io_guy]

Thanks for the reply,
I did all that and followed the manual, type B (center terminals). If I reverse one CT's polarity everything nulls as expected. The other channel (7) is only a single CT with doubling and has the same issue. I've never changed the current constant, it shows 221.

I don't understand how this is anything but a GEM software issue. Regardless of whether the CT is setup correctly, the GEM's DAC will either have current or voltage as its primary input variable. The other will simply be a software calculation of P=VI (and PFC) where V is the PT input voltage (which is displaying correctly on my system at ~119V). In no world does 3.3kW correlate to 54.5A.

[Teken]

Thanks for the reply,
I did all that and followed the manual, type B (center terminals). If I reverse one CT's polarity everything nulls as expected. The other channel (7) is only a single CT with doubling and has the same issue. I've never changed the current constant, it shows 221.

I don't understand how this is anything but a GEM software issue. Regardless of whether the CT is setup correctly, the GEM's DAC will either have current or voltage as its primary input variable. The other will simply be a software calculation of P=VI (and PFC) where V is the PT input voltage (which is displaying correctly on my system at ~119V). In no world does 3.3kW correlate to 54.5A.

Simple test, roll back to an earlier firmware and see if it corrects the issue.


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[ben]

Just hooking my GEM back up in my new place. Updated to firmware 5.13 and things are communicating fine.

I have channel 4 that's not making sense. The power is likely in the right ballpark, the current as you can see makes no sense. 2 Micro-80s used and the channel configured for them (2-pole circuit):

Can you send over screenshots of your Status screen and Advanced screens? What version did you upgrade from?

What's on channel 5? Is it a Split-CT?

[io_guy]

I went from 4.33.

Here's the 3 images you requested. I have only populated 4 channels so far. The split-60 (chan 5) seems to be reading ok.

Screenshot 2020-11-24 150556.jpg (33.18 KiB) Viewed 1662 times

Screenshot 2020-11-24 150553.jpg (253.14 KiB) Viewed 1662 times

Screenshot 2020-11-24 150549.jpg (54.12 KiB) Viewed 1662 times

[io_guy]

Just downgraded to 4.33 but it made no difference. I hooked up a couple more CTs. The main splits (chan 1 & 2) read fine, a new Micro-40 (chan 12) also has odd readings.

Screenshot 2020-11-24 161741.jpg (33.4 KiB) Viewed 1661 times

[ben]

Just downgraded to 4.33 but it made no difference. I hooked up a couple more CTs. The main splits (chan 1 & 2) read fine, a new Micro-40 (chan 12) also has odd readings.

Curious if these readings are just in the Live Data area or in the actual packet. If you switch to the HTTP Get packet, it should list them similar to c1=X,Y,Z. Z should be amperage.

[ben]

What are you monitoring on the Micro-CT channels?

I wonder if it's also possible if you can you put a Split-CT on the same load on the same channel to see if it has the same issue?

Also, can you download your settings file and send it over? Last one on the menu. Email it over to ben(at)brultech.com, we'll upload it to a unit here to see if there's any weird setting causing it.

EDIT: send to support(at)brultech.com