Regarding the iTHD register value of the HDPM6000 branch circuits

[T.Okada]

Hi,

I noticed a mismatch between the iTHD (%) description in the HDPM6000 protocol guide and the measured values.

The protocol guide states the following:

I compared the Modbus iTHD (%) values for the branch circuits with the values shown on the HDPM6000 web interface. If the description above is correct, the web values should be 0.41%, 0.31%, and 0.27%, but the web interface shows 4.1%, 3.1%, and 2.7%.

Is this an error in the manual, or are the web interface values incorrect?

Regards,
Okada

[Mehran_Mehrnia · Accepted solution]

Hi @T.Okada 

The web interface is correct. The manual’s statement that harmonic distortion values are expressed in units of 0.1% is also correct.

However, the example shown in the manual places the decimal point incorrectly. A value of 27 in the Modbus register should be interpreted as 2.7%, and this same value will be displayed as 2.7% in the web interface.

Therefore, the values shown on the webpage (4.1%, 3.1%, and 2.7%) are correctly correlated with the values returned via Modbus (41, 31, and 27), which are divided by 10 and expressed as percentages.

Best Regards,

-Mehran

L3 Expert Advanced metering

[T.Okada]

Hi @Mehran_Mehrnia 

Thank you for your kind reply.

I now understand the iTHD value of the HDPM6000.

Regards,

Okada