The sorting rule
Use this rule on every site: if it is essential for a comfortable evening during a power cut, it belongs on backup. If it draws too much or starts with a surge the backup port cannot handle, it stays grid-only.On the essential (backup) panel
| Load type | Notes |
|---|---|
| Lights (LED) | Low draw, high value |
| Ceiling fans | Low draw |
| Router and networking | Essential for work-from-home |
| TV and entertainment | Reasonable draw |
| Phone and laptop charging | Low draw |
| Alarm and CCTV | Security — always include |
| One refrigerator | Size to rated power only on Kent M1; include where the platform’s motor-start capability covers it (see Note below) |
Grid-only, always
| Load type | Reason |
|---|---|
| Air conditioners | Compressor surge and running draw exceed backup port ratings |
| Geysers and water heaters | Resistive load — very high draw |
| Ovens and induction hobs | High resistive draw |
| Washing machines and dryers | Motor surge plus high running draw |
| Large pumps | Surge current often exceeds backup ceiling |
| EV charging | Sustained high current |
| Welding equipment | Surge and arc current — never on backup |
On the Kent M1, do not add a refrigerator to the essential panel unless the refrigerator’s rated running current fits comfortably within the model’s backup current limit (15 A / 25 A / 30 A) with other essentials running simultaneously. The M1 manual publishes no motor-start surge figure. [KNB-VAL-02]
The arithmetic
Add up the realistic simultaneous draw of the essential circuits in watts. Compare it to the platform’s backup rating from Backup Can & Can’t. Leave headroom — you are designing for a real evening, not nameplate theory. Example — Kent M1 5 kW (5 500 VA / 25 A):| Circuit | Estimated draw |
|---|---|
| 10 × LED lights | 100 W |
| 3 × ceiling fans | 200 W |
| Router | 30 W |
| TV | 150 W |
| Phone charging × 4 | 80 W |
| Alarm + CCTV | 60 W |
| Refrigerator (running) | 150 W |
| Total | 770 W |
Wiring discipline
Feed from the backup port's own protected branch
The essential panel feeds only from the inverter’s backup port output. Grid and backup circuits never share downstream wiring. Follow the platform AC wiring page: Kent M1 AC Wiring or Kent G3 AC Wiring.
Label everything
Label the panel (“BACKUP — ESSENTIAL LOADS”), each way in the board, and stick the DO/DON’T card on the door. The next electrician must understand the split in ten seconds without asking anyone. Photograph the labelled panel.
Prove it, then hand it over
Run the black-start test
Open the grid breaker. Confirm that the essential panel rides through — lights on, router up, TV running. Confirm that grid-only loads stay dead. Close the grid breaker and confirm clean return.
Photograph the panel
Photograph the labelled essential panel, the DB split, and the test in progress. This photo belongs in the job record and on the handover form.
Common mistakes
Whole house on backup 'for now'
The first real outage produces an overload trip. There is no “for now” — the split must be right before handover.
AC on essentials because the customer insisted
Put the refusal in writing, or escalate. Do not let a customer override a safety and capacity decision at handover.
Unlabelled split
The next AC installer taps the backup panel for a new 2-ton unit. Clear labelling is the only defence.
All essentials on one G3 phase
On a three-phase G3, piling all essentials onto one phase delivers half the promised capacity before the phase ceiling is hit.
When to escalate
Escalate to Kent New Energy service only — through your registered Kent partner channel or the Kent service desk details on your work order. Do not contact any third-party or component-manufacturer support line for a Kent-branded system: tickets outside the Kent channel are not tracked, not covered, and can void warranty handling.