A9MEM1570 showing negative power

[tomsilver]

Hi, 

I have a newly installed PowerTag A9MEM1570 which reports negative values for all 3 phases. At the same time, both current and voltage show positive values. 

Referring to https://www.se.com/uk/en/faqs/FA86375/

this might indicate that the device is installed the wrong way around. 

However, the figures in the installation guide do not show the supposed direction of the load.

Could someone please clarify about the correct installation?

[Charles_Murison]

Hello @tomsilver ,

I do not know the A9MEM1570. Voltage and current will never have a negative magnitude. These are RMS values that have a magnitude and phase. This phase angle is important. A phase angle is the time difference between the voltage and current stated in degrees between 0-360 or 0-180 leading or lagging. 

For currents, if a device is "backwards" the phase angle is changed by 180 degrees. This could possibly explain why you are seeing negative kW.

Regards,

Charles

[Thierry_Baudard · Accepted solution]

Hi @tomsilver 

Hi

The reason could be  the installation of the PowerTag who does not measure current  in the right direction.

If you refer on the Installation sheet of PowerTag A9MEM1570, there is a figure to indicate the position of the PowerTag (screenshot hereunder) to obtain a correct measurement.

Instruction Sheet for PowerTag F63 - A9MEM1560 - A9MEM1564 - A9MEM1570 - A9MEM1573 - A9MEM1574 | Sch...

Now if the Gateway is a Panel Server, you  also have the possibility  modify the configuration in the web page without need to dismount the PowerTag in the panelboard => screenshot hereunder