Hello,

The documentation states that the device measures both the power factor and cos φ.

However, only the power factor value is available in the Modbus table. This can be confusing, as these two values are often similar but can differ.

- Whether these two values are identical or not
- Whether cos φ is available via Modbus
- Or whether it must be calculated from the available information

Have a nice day !

Hello ETN;

From the Siemens FAQ 7KM: Difference between cosine phi and the power factor:

https://support.industry.siemens.com/cs/ca/en/view/51402748

The PAC3220 only provides the power factor (for each phase), you can calculate the Cos PHI with this equation:

"Cos ij results from the ratio of effective power (P) to fundamental apparent power (S1). Power factor Ȝ = cos ĭ results from the ratio of effective power (P) to total apparent power (S) from fundamental and harmonics."

In the appendix of this PAC 3220 manual, you will find the Modbus registers of your unit, and find the address of the power factor (per phase, total, max, min...) but not the cos PHI. You can use the registes for Apparent and Active (effective) power to calculate the cos PHI if you need it.

https://support.industry.siemens.com/cs/ca/en/view/109767307/180448729867

Hope this helps,

Daniel Chartier