Growatt SPF 02 — Over-Temperature Shutdown

What it means: The inverter's internal temperature sensors read above the safe working limit, so the unit derates or shuts down to protect its power stage. Growatt's off-grid guide gives the trip condition as internal component temperature over 100 °C. There are two very different situations behind this code — the inverter really is too hot, or one of the four internal NTC temperature sensors has failed and is reporting a false high.

Why does Growatt show 02?

• Ambient temperature above the inverter's allowed range — a closed store room, a stairwell cupboard, or a west-facing wall in a Pakistani summer
• Airflow blocked by dust-clogged heatsink fins, a blocked intake, or the unit boxed into a cabinet or behind curtains
• Fan not turning, which usually shows warning 01 alongside this code
• Sustained near-full load, so the power stage runs hot even at normal ambient
• A failed or loose internal NTC temperature sensor cable reporting a false high — Growatt notes there are four NTC sensors inside and dedicated software to find the broken one

The Pakistan factor

This is the most seasonal Growatt fault in Pakistan. Rooftop store rooms and stairwell cupboards in Lahore, Multan and Jacobabad routinely sit above 45 °C ambient in June and July, and the inverter's own losses add to that. Fine summer dust blankets heatsink fins and fan blades within a single season, so a unit that ran cool last year will trip this year on exactly the same load. The common local remedy of pointing a pedestal fan at the inverter does help, but it masks a blocked heatsink rather than clearing it — have the fins cleaned properly at service time. Never solve 02 by moving the inverter outdoors under a plastic sheet or a shed roof. Water ingress is a far more dangerous fault than heat, and a shaded indoor wall with a vent beats an outdoor location every time.

How to fix it

1. Read the display and note when 02 appears. A fault that arrives in the afternoon heat and clears in the evening is a cooling problem. A fault that appears on a cool morning is a sensor problem. Write down which one you have before calling anyone.
2. Safe for a homeowner — check the inverter has clear space around it, that nothing is stacked against it, and that the intake and the wall behind it are not choked with dust. Confirm you can hear and feel the fans running.
3. Safe for a homeowner — improve the room. Shade the wall, open a vent or air brick, add a room fan, and move stored boxes away from the unit. Growatt's first suggested check is simply whether the installation environment allows heat to escape.
4. Safe for a homeowner — cut load during the hottest hours. Running near full rated output at 45 °C ambient will trip a healthy inverter.
5. Do not open the inverter to clean the heatsink or check the NTC cable. Growatt's own sensor procedure begins with removing the front cover of a unit that has battery, PV and utility all live behind it. That is installer work, not homeowner work.
6. If 02 persists with good airflow and moderate ambient, or appears on a cool morning, stop here. A false high reading points at an NTC sensor or the board. Call your installer or Growatt service and give them the timing pattern you recorded.