Support Rogowski PowerLogic HDPM6000

[alexfmedina]

Hi team,

I am currently working on a retrofit project using a PowerLogic HDPM6000 system to monitor 16 three-phase branch circuits (48 phases total, 800A and 1200A feeders) inside an existing Eaton switchboard.

Due to severe space constraints and conductor density (2 to 4 parallel conductors per phase tightly packed along the lateral wireway), standard rigid split-core CTs—including the METSEHD series—physically cannot fit. Flexible Rogowski coils are our only viable physical mounting solution.

Since HDPM6000 channels are designed for a 250 mV full-scale input and do not take raw Rogowski mV signals directly, we are planning to use a 3rd-party 3-phase DIN-rail Rogowski integrator (TPV series) which outputs 333 mV RMS at rated current (e.g., 333 mV @ 800A / 1200A).

I would like to confirm the following points::

1. Custom Scaling / CT Factor Support: Can we safely scale the 333 mV input to match the HDPM6000’s 250 mV internal base scale using the Advanced CT Editing / CT Type Table (CSV) without clipping or degrading measurement accuracy?

2. CT Factor Calculation: For a 333 mV nominal output sensor, is applying the ratio Factor = 250mV/333mV=approx 0.7507 within the custom CT table the approved method to achieve correct amperage, power, and energy readings?

3. Phase Angle (PHCAL): Does the HDPM6000 require a specific PHCAL phase shift compensation when interfacing with an active electronic integrator that already shifts the Rogowski signal by 90°?

Looking forward to your technical confirmation. Thanks!

[Mehran_Mehrnia · Accepted solution]

Hi @alexfmedina 

As already known, the HDPM6000 current inputs are designed around Schneider-qualified LVCTs and nominal 250 mV low-voltage CT outputs. When integrating Rogowski coils with 333 mV integrators, the following key points need to be considered.
Please note that these represent my initial technical assessment. I have also requested final confirmation from our technical team and will update this post if any refinements are needed.

1. Custom Scaling / CT Factor Support & Clipping Risk

To maintain linear measurement accuracy and prevent waveform distortion, the integrator must be physically configured so that the maximum output voltage delivered to the HDPM6000 stays at or below 250 mV RMS under all anticipated operating conditions. Assuming that a 333 mV sensor can be connected directly at full scale and corrected solely through CT table scaling (CT Factor) is not recommended, as software scaling cannot recover a signal that has been clipped by the hardware ADC.

• Example: For an 800 A load, selecting the 1200 A DIP setting (which outputs 333 mV RMS at 1200 A) produces 222 mV RMS at 800 A nominal load. This keeps the signal under the 250 mV limit while providing a safety headroom margin that accommodates current spikes up to 900 A (250 mV) without hitting hardware saturation.

2. CT Factor Calculation

From the HDPM6000's perspective, the 1200A <-> 333mV integrator setting functions as an equivalent 900A <-> 250mV LVCT (1200A * (250mV/333mV) = 900A)).

When adding this as a custom 250mV CT profile in the meter (via Advanced CT Editing with Factor: 10.746), or you simply set the primary rating to 900 A as Nominal CT Current using New CT button. The HDPM6000 firmware will automatically apply its internal baseline scaling coefficient (CT Factor = Primary/83.75 = 900/83.75 ≈ 10.746) to deliver correct amperage, power, and energy readings.

3. Phase Angle Compensation (PHCAL)

• Net Phase Shift is 0°: The Rogowski coil output leads the current by 90° (di/dt derivative signal), and the active electronic integrator applies -90° integration shift over time. Combined, they cancel out to a 0° net phase shift, delivering a signal that is aligned with the primary line current. Therefore, PHCAL of 0 can be relied on the Rogowski and integrator accuracy claim.

Best Regards,

-Mehran

L3 Expert Advanced metering

[alexfmedina]

Hi @Mehran_Mehrnia 

Thank you so much for your reply, it was very helpful. I understand it much better now.

Regards.