Solis OV-TEM (Alarm 1032) — Over Temperature
What it means: The inverter has shut down or cut back its output because it is too hot. Solis logs it as alarm 1032 and describes it two ways in their own documentation: their service centre says the alarm appears when the inverter detects a high ambient temperature above 60 °C, and their alarm-code list describes 1032 as the internal temperature near the power switching devices exceeding the limit. Both describe the same thing — heat is going into the unit faster than it can get out. The single-phase S5 and S6 are rated for ambient temperatures up to +60 °C and are cooled by natural convection, so the alarm is nearly always about where the unit is mounted rather than about a broken part.
Why does Solis show OV-TEM?
- Direct afternoon sun falling on the inverter. The Solis manual's remedy for this row is to check whether there is sunshine directly on the inverter in hot weather
- Poor ventilation around the unit — mounted in a closed store room, a cupboard, a stair void, or hard against other equipment
- The manual's other listed remedy for this row — inadequate ventilation in the space surrounding the inverter
- Dust caked on the heat-sink fins, which is what natural convection cooling depends on
- Ambient air genuinely above the 60 °C the unit is rated for, or a blocked fan on the larger models that have one
The Pakistan factor
Pakistan is where this code lives. Shade temperatures through May and June across Multan, Sukkur, Jacobabad, Sibi and much of southern Punjab and Sindh sit close to the top of the 60 °C ambient rating before you add any sun on the enclosure itself, and the two most common local mounting habits both make it worse. The first is bolting the inverter to a bare west-facing external wall, where it takes full afternoon sun on the enclosure exactly when ambient temperature peaks. The second is the opposite instinct — hiding it in a closed store room, a servant quarter, or a cupboard under the stairs to keep it out of the dust, which removes the airflow the design depends on. Dust itself is the third factor: a Thar or Cholistan dust season leaves a felt layer on the fins within a couple of years, and on a naturally cooled inverter that layer is the difference between derating and tripping. A shaded, well-ventilated north-facing wall with clear air above and below the unit avoids nearly all of this.
How to fix it (safe to try yourself)
- Look at where the inverter is mounted, at 3 pm on a hot day. If the sun is on it, that is your answer and no other diagnosis is needed.
- Do not touch the inverter's surface while it is running. The manual is explicit that parts of it can be hot enough to burn.
- Check the clearance around it. Natural-convection cooling needs air to rise freely past the fins, so anything stacked against it, a closed cabinet, or a shelf directly above it will cause this alarm on an otherwise healthy unit.
- Have shading added — an awning or a shade board that keeps direct sun off the enclosure without boxing it in or restricting the airflow past it. Relocating or shading the unit is installer work, not something to improvise.
- Clean the dust off the heat-sink, exactly the way the manual prescribes — shut the inverter down following the stop procedure in section 5.2, let it cool completely, then brush the fins with a soft brush. Never use solvents, abrasives or corrosive cleaners, never spray water at it, and never open the enclosure to clean inside it.
- Expect some derating on the hottest days. An inverter that quietly produces less at 2 pm and recovers by evening is protecting itself and is behaving correctly; only a hard OV-TEM shutdown needs acting on.
- If OV-TEM appears at moderate ambient temperatures, or the temperature shown in the inverter's Advanced Information menu does not match the temperature you measure in the same room, stop there. Solis's own instruction for that mismatch is to contact their support — it points to a sensor or internal fault, and there is nothing safe for you or your installer to do inside the case.