I have a question regarding reading import and export energy from an electricity meter, the system has a solar array fixed allowing power to be exported to the energy grid when there is excess power.

The link to the energy meter I am interested in (CL model), is below: https://www.accuenergy.com/files/acuvim-l/Acuvim-L-Power-Meter-Brochure-1030E1210.pdf

On page 2 the real time energy functions are listed, this should all be available over MOD bus. I believe all I need to read to obtain import power is Power P1,P2,P3,Psum? I believe all I need to read to obtain export power is Reactive Power Q1,Q2,Q3,Qsum?

The functions Energy and Reactive Energy see more appropriate but share the same parameters.

Could someone please clarify if this is correct or provide what parameters are required to read and calculate the exported power?

  • \$\begingroup\$ Why don't you speak with the supplier? This isn't really an EE question. \$\endgroup\$
    – Andy aka
    Commented Aug 15, 2016 at 7:15

1 Answer 1


Having designed a number of energy meters over the years, I can say with authority that reactive energy (Q) is not the same as exported energy (PE), in fact it has basically nothing to do with it. What you need is an energy meter that has separate counters for imported real energy (P) and exported real energy (PE).

Reactive power is basically only relevant for industrial metering, but in case you're interested, an energy meter can additionally have up to four counters for reactive energy (Q), these being, in order of real world relevance, inductive (QIND) and capacitive (QCAP), exported inductive (QEIND) and exported capacitive (QECAP). When there are six registers in total, the sign of real power is used to select which registers are accumulated.

Most important, however, is that when money is involved (the meter is used for billing), the exact meter brand and model must be accepted by your power grid company. If money is involved, they may also come and seal the meter themselves with their own seal, although the practice varies from company to company in different countries.

When you're reading the registers, be sure to note the difference between instantaneous power (P) and accumulated energy (W). The register names for instantaneour powers might be something like P, PE, Q, QIND, QCAP and the energies might be something like W, WE, WQ, WQIND, WQCAP etc.

  • \$\begingroup\$ Thank you PkP for the clarification, I had that mixed up! I can see on the data sheet it actually has an Energy function with parameters listed as Ep_imp, Ep_exp. As with Andy's comment I will now contact the supplier. \$\endgroup\$
    – Suze1990
    Commented Aug 15, 2016 at 14:55

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