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Meters extend what a bare CT can do on reach and on multi-source sites. Three-phase sensing adds a discipline that single-phase experience never teaches: every CT must match its conductor and its terminal pair — all three at once.
For trained and authorised installers only. Meter wiring is live-side work. Isolate before connecting or modifying any meter terminals.

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When to use a meter instead of direct CTs

A supported energy meter carries its own CTs and reports over RS485 to the inverter. Use a meter scheme when:
  • The grid connection point is beyond the CT lead’s design reach [KNB-VAL-23]
  • The site design shipped with a meter scheme
  • AC-coupled metering is required at a multi-source site
Run one sensing scheme per site — either direct CTs or a meter, not both simultaneously. Platform-specific meter options, terminal maps, and kit ratios:

Kent M1 CT & Meter

Supported meters, terminal mapping, 3-CT single-phase schemes, and 6-CT three-phase AC-couple schemes are on the Kent M1 CT & Meter page.

Kent G3 CT & Meter

Meter scheme, pin map, kit ratios, and installation location options (Grid side / Load side / Grid + PV inverter) are on the Kent G3 CT & Meter page.

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RS485 polarity — A on A, B on B

Meter communications fail on swapped polarity more than any other wiring error. Land A on A and B on B at every termination point, using signal name rather than pin number as your reference — on the Kent G3 the meter end and the inverter end use different pin numbers for the same signal pair.
SymptomLikely cause
Meter comm fault, no grid data on displayA/B swapped at one end, or meter supply circuit is dead
Comm fault only during backup testMeter powered from a circuit that goes dead when grid is lost

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Three-phase discipline: match everything, per phase

On a Kent G3 three-phase installation, three CTs must agree with three conductors and three terminal pairs simultaneously.
1

Match CT to conductor by phase

The L1 CT clamps on the L1 conductor. L2 on L2. L3 on L3. Right phases with crossed leads is still wrong.
2

Match CT leads to the correct terminals

The L1 CT’s leads land on the CT-L1 terminal pair. L2 leads on CT-L2 terminals. L3 leads on CT-L3 terminals.
3

Check arrow direction on every CT

Every CT’s arrow toward the grid — the universal Kent rule applies on all three phases.
4

Prove it per phase with a stepped load

Step a known single-phase load on L1 only. The display’s L1 reading rises; L2 and L3 stay flat. Repeat for L2 and L3. Photograph each step.
The classic three-phase mismatch signature is one phase importing while another phase discharges on the same display simultaneously. Treat that pattern as a phase-mapping error until the per-phase live test proves otherwise.

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AC-coupled and multi-source sites

Where an existing grid-tie PV inverter shares the site, the metering scheme must account for its generation:
  • Kent M1 AC-couple schemes place a CT on the grid connection and a second CT on the existing solar inverter’s output — detailed on the Kent M1 CT & Meter page.
  • Kent G3 offers the Grid + PV inverter meter placement option for the same scenario.
Retrofit expectation for third-party grid-tie inverters: a third-party grid-tie inverter on the grid side has no control channel to the Kent hybrid. The system can meter its output but cannot command it to reduce generation. This has a direct impact on zero-export performance — plan export behaviour accordingly and engage Kent service before quoting a multi-source retrofit.

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Common mistakes

A continuity test on swapped RS485 polarity passes because both wires are present. It fails at comm. Wire by signal name: A on A, B on B.
Grid data vanishes exactly when you need it most. Power the meter from a circuit that survives a grid outage.
Speed at the enclosure costs an hour of troubleshooting. Match conductor, leads, and terminals per phase before closing up.
Only one sensing scheme per site. Two schemes conflict and produce corrupted grid data.