Hello,
I am located in the US and have two 200 AMP split-phase load centers. I am using two WEM3080T units—one for each panel—and a Fluke 87V (True RMS) multimeter with an I400 CT clamp to verify AC current readings.
The WEM3080T unit installed on Panel 1 accurately reports the correct current. However, the unit installed on Panel 2 consistently reads approximately 33% higher than the current measured by the Fluke.
To troubleshoot, I have already verified the direction of the CT clamps and confirmed that the connections are correct. Additionally, when I swapped the working WEM3080T from Panel 1 to Panel 2, it provided accurate readings. This leads me to believe there may be a defect or issue with the WEM3080T unit assigned to Panel 2.
The firmware version on the unit is i.76.057. Could you please advise on any next steps to address this issue? I am happy to provide any additional data or perform further troubleshooting if needed.
Thank you for your assistance!
Best regards,
Dave
Hi Dave:
please let me know
1 whether the power value is correct or not?
2 could you clamp all 3 CT (on the problematic WEM3080T) on the same wire, whether the current reading is the same ?
3 whether the normal WEM3080T is also with the version of i.76.057
4 how do you read the current reading? by modbus/tcp ,API or just from our app/web system.
Hello -
I have attached all 3 CTs (A,B,C) to the same leg in load center 2. The 3 clamps are all reading different values, however the the C-CT is reading the correct current value as the Fluke 87 V True RMS, in this test amp reading is 12. The monitoring is setup using MQTT with 1 sec deply.
Here are the readings from the MQTT Explorer app.
- voltage: 120, current a: 18
- voltage: 120, current b: 15
- voltage: 120, current c: 12 (this is correct and matches Fluke 87 V)
1) Voltage values are correct for each phase (120v)
2) Power readings for A & B CTs are incorrect, as the amp readings are incorrect. However, C-CT amp and power readings are correct.
3) Both WEM3080T units are running the same firmware version i.76.057
Thanks for your detailed information
"I have attached all 3 CTs (A,B,C) to the same leg in load center 2. The 3 clamps are all reading different values,"
Do you mean you have clamped all 3 cts on the same wire? If so ,please give me a photo (that all 3 CTs are clamped in the same wire)
We apologize for the complexity of the requirements, but this is the easiest way to verify the issues mentioned in the following guide:
https://www.iammeter.com/newsshow/blog-meter-accuracy#how-to-confirm-whether-the-energy-meter-is-damaged-during-shipment
As all devices undergo an aging process before leaving our factory. One of the steps involves applying a fixed power value to the three phases and comparing the meter's current and power readings. If there is a significant discrepancy in the current or power readings, the device would not pass our quality control and would not leave the factory.
To assist you further, please email us at support@devicebit.com with the serial number (SN) of your device. We will check the aging record associated with this SN.
For security reasons, we strongly advise against posting the SN publicly in this forum.