Regarding the split phase settings of HDPM6000

[Tomohiro-Okada]

Hi,

I have a question about the settings of HDPM6000.

I believe that to set single-phase three-wire in HDPM, you can select Split Phase under the General Settings tab. However, how should we configure branch circuits that take voltage from R-T (i.e., circuits using R-T for voltage)?

On the HDPM web interface, the Exp Phase options only allow selecting 1, 2, 3, or N, which seems to only support cases where voltage is taken from the N line. How should we configure for circuits that take voltage from R-T?

Thank you,

@Tomohiro-Okada 

[Mehran_Mehrnia]

Hi @Tomohiro-Okada 

As mentioned in HDPM6000 Installation guide:

If you have single-phase three-wire coming from a center-tapped transformer (the two hot legs are 180° apart), choose Split supply type.

If you have single-phase three-wire coming from two legs of a Wye transformer (which are 120° apart), you need to choose Wye supply type, because the electrical characteristics match a Wye system (120° phase difference, not 180°).

For circuits using R-T voltage in Split Phase mode, configure the branch circuit with two CTs, assign them to Phase 1 and Phase 3, and group them together into one circuit. The HDPM will calculate line-to-line voltage (R-T) internally based on the Split Phase supply type.

Best Regards,

-Mehran

L3 Expert Advanced metering

[Tomohiro-Okada]

Hi @Mehran_Mehrnia,

Thank you for your reply.

I understand the configuration for circuits using the R‑T voltage in split‑phase mode.

So, if I would like to configure a 42‑circuit system using the R‑T voltage in split‑phase mode, I would need to use the METSEHDPM6R84 (not the METSEHDPM6R42). Is my understanding correct?

Best regards,
Okada

[Mehran_Mehrnia]

Hi @Tomohiro-Okada 

You're welcome.

You're correct. If each circuit using R-T voltage in Split Phase mode is monitored with two CTs (one on R and one on T), then the METSEHDPM6R84 would be required to support 42 such circuits. The METSEHDPM6R42 only supports up to 21 circuits in this configuration.

Also, just to clarify a point from my previous note. When configuring branch circuits in Split Phase mode that use R-T voltage, it's better to assign the CTs to Phase 1 and Phase 2, rather than Phase 1 and Phase 3, since using Phase 3 would misrepresent the electrical configuration.

While the HDPM calculates line-to-line voltage internally based on the Split Phase supply type, using Phase 1 and Phase 2 aligns with the expected configuration and helps maintain consistency with documentation.

Best Regards,

-Mehran

L3 Expert Advanced metering