Wrong-CT Symptoms

A wrong CT rarely announces itself — it makes the system look broken. This page maps each reading pattern back to the clamp.

The symptom map

What you see	What it means	Fix
Import/export signs flipped; battery discharging to the grid	CT reversed, or on the wrong conductor	Physical direction per Direction & Location; re-run the live test
Load reads 0 W with loads clearly on	CT clamped around live and neutral — fields cancel	Re-clamp on the live only
Power wrong by a large factor	CT ratio setting doesn’t match the clamp	Set the ratio exactly per the shipped CT nameplate [KNB-VAL-08]
Fast power fluctuation with steady loads	CT direction wrong — the control loop is chasing itself	Verify arrow-to-grid, then the live test
One phase imports while another discharges	CT-to-phase mismatch (three-phase)	Re-map per Meter & Phase Matching
Phantom import/export, noisy small readings	Extended or damaged CT lead picking up noise	Restore the design lead; no extensions [KNB-VAL-23]
Export logic dead, grid figures frozen	CT lead open-circuit or unseated at the terminal block	Continuity + reseat per the platform CT page

The platforms flag CT trouble differently — read your platform’s signal:

Kent M1: the LCD raises E106 (Meter or CT abnormal) — check direction, phase and cable continuity — and E107 (Meter or CT reverse connection) — check the CT wiring. An anti-backflow breach (often CT-rooted) raises E105.
Kent G3: there is no dedicated CT alarm for a reversed clamp — the tell is the fast-fluctuating power pattern above and wrong flow on the screen; the source manual’s FAQ sends you straight to the CT arrow.

Location — grid connection point, live conductor only.
Direction — arrow toward the grid.
Phase mapping (Kent G3) — CT, conductor and terminals all matching.
Ratio — exactly the shipped CT’s nameplate. [KNB-VAL-08]
Only now touch orientation settings (M1 Meter CT orientation / G3 Forward–Reversal), and only to state the physical truth.
Re-run the Energy-Flow Test — a CT fix without the live test is a guess.

“Fixing” a reversed clamp with the Reversal setting when the clamp is right there — physical first; software direction is for CTs that genuinely cannot be re-clamped now.
Swapping settings for an hour when the load reads 0 W — that one is always the L+N clamp.
Declaring the CT fine because the sign is right at noon — with PV masking import, the sign proves nothing; test grid-on/PV-off.
Blaming the battery for “discharging to grid at night” — flipped CT, nine times in ten.