Questions
1. The universal CT placement rule on both Kent platforms is: clamp the CT around the:- A. Grid main live conductor only — arrow pointing toward the grid
- B. Backup feed conductor — arrow pointing toward the loads
- C. Live and neutral together — arrow in either direction
- D. Earth conductor at the incomer
2. If you install a CT with the arrow pointing toward the loads instead of toward the grid, the most likely symptom is:
- A. The system shuts down immediately
- B. Erratic power readings with sustained or fluctuating export even under stable load conditions
- C. The battery stops charging
- D. E100 appears on the Kent M1
3. Clamping the CT around both live and neutral conductors together results in:
- A. Double the correct reading — a 2× calibration error
- B. A reading of 0 W — the equal and opposite currents cancel
- C. A negative power reading
- D. An overcurrent fault on the inverter
4. The CT ratio setting in the inverter must be taken from:
- A. The platform’s factory default — it is pre-configured for the shipped CT
- B. The DISCOM’s standard CT ratio table for the region
- C. The nameplate of the specific CT shipped with the system — read it and set exactly that
- D. The meter’s LCD display
5. On both Kent platforms, extending the CT signal lead with additional cable is:
- A. Acceptable up to 10 m using shielded twisted-pair cable
- B. Acceptable using any matching cable up to 5 m
- C. Not permitted — if the lead does not reach, use the platform’s meter scheme instead
- D. Acceptable if the cable resistance is below 2 Ω
6. On the Kent M1, when zero export is required, the Solar Sell setting must be:
- A. ON, with Max Sell Power set to 0 W
- B. OFF — and the zero-export witness test against the utility meter is mandatory before sign-off
- C. Removed by deleting the CT entry
- D. Set to the DISCOM’s published limit automatically
7. On the Kent G3 site with no feed-in permission, zero export is set by:
- A. Setting Max Export Power to 0 in the grid settings
- B. Setting Allow Export to maximum — the CT limits it physically
- C. Leaving the export settings at factory default
- D. Changing the grid code to a no-export variant
8. What does a short spike of export during a large load switch-off tell you about the zero-export setup?
- A. The CT direction is reversed
- B. The export limit value needs halving
- C. Spikes on load switching are physics — they are not evidence of a zero-export failure; sustained export is the failure mode to investigate
- D. The meter RS485 address is wrong
9. The Kent M1 E106 fault code relates to:
- A. Battery undervoltage
- B. CT abnormal — check CT installation, direction, and connection
- C. Grid overvoltage
- D. Fan failure
10. Zero-export control via the CT and inverter cannot control:
- A. The battery discharge rate
- B. The PV output on the Kent M1
- C. Third-party grid-tied (GT) inverters on the same supply — they are invisible to the Kent system
- D. The backup loads during an outage
Answer key
| Q | Answer | Why |
|---|---|---|
| 1 | A | CT on the grid main live conductor, arrow toward the grid. This applies to both Kent M1 and G3. Installing on a sub-circuit or with the arrow reversed both produce incorrect control. |
| 2 | B | A reversed CT causes erratic or persistently wrong power readings. The control loop chases the wrong signal, producing fluctuating display values and potential sustained export. |
| 3 | B | Clamping around both L and N means equal and opposite currents cancel — the CT reads 0 W. The inverter sees no load and cannot control export. |
| 4 | C | Always read the nameplate of the shipped CT and set that exact ratio. Never assume a default — the shipped CT ratio is confirmed on the nameplate only. |
| 5 | C | CT signal lead extensions are not permitted on either platform. If the lead cannot reach the grid connection point, use the platform’s smart meter scheme instead. |
| 6 | B | On the Kent M1, Solar Sell OFF is the zero-export setting. The witness test against the utility meter is mandatory before the job is signed off. |
| 7 | A | On the Kent G3, set Max Export Power to 0 in the grid settings. This is the correct zero-export configuration for a no-feed-in site. |
| 8 | C | Brief spikes on large load transitions are a physics effect — the inverter cannot respond in zero time. Sustained export is the indicator of a real zero-export failure. |
| 9 | B | E106 on the Kent M1 is a CT abnormal fault. Check the CT installation, direction, connection, and ratio setting. |
| 10 | C | The Kent zero-export control loop only controls the Kent inverter’s own output. Third-party GT inverters on the same supply are invisible and will export independently. |