Manuals · on-grid
Cheapest solar. Also the one that goes dark with WAPDA.
Covers Huawei SUN2000, Growatt MIN, Solis string, Sungrow string, Fronius Primo / Symo (without GEN24 backup), Inverex Nitrox 10 kW 3P on-grid lots. Official hubs: Huawei FusionSolar, Growatt, Fronius Solar.web, Sungrow. If you bought a hybrid and this page describes your nights, someone sold you the wrong letter on the nameplate.
What the box is allowed to do
An on-grid / string inverter converts PV to AC and pushes it in parallel with WAPDA. It is legally required to stop the instant the feeder dies (anti-islanding). That protects the lineman. It is not a defect, a setting you “unlock,” or something a WhatsApp firmware fixes. If you need fans at 2 a.m., you wanted a hybrid + LFP.
Right product: day factory that already has a genset, office on a feeder that barely sheds, C&I chasing PKR/kW. Wrong product: a Multan house with six-hour nights. Policy: on-grid vs hybrid, net-billing file.
Ports
| Port | What it is |
|---|---|
| PV / MPPT | Strings via DC isolator. Voc under the datasheet max on a cold morning — same rule as hybrid. |
| AC OUT | To the DISCO-side AC breaker / generation meter. Not a “backup” socket. |
| COM / dongle / RS485 | FusionSolar / Solarman / Solar.web / iSolarCloud. Monitoring only. |
| Battery | There isn’t one. Huawei LUNA / Fronius GEN24 + BYD are different architectures — only if the quote named them. |
Commissioning (short)
- Earth the chassis and structure. Same rod as the house if the electrician drew it that way.
- Measure string Voc with the isolator off the inverter. Land PV. Close isolator in sun.
- Close the AC generation breaker only after the DISCO / consultant said the bidirectional meter is in. Exporting into an old unidirectional meter is theft on paper.
- App: FusionSolar (Huawei), ShinePhone/Solarman (Growatt MIN), Solar.web (Fronius), iSolarCloud (Sungrow). Owner account, not the shop’s.
Daily use after SRO 251 (9 Feb 2026)
Import is still Rs 37–55 a unit on the slab. Export is NAEPP / street ~Rs 8–13 (we use Rs 11 in the calculator). The box will export whatever you do not self-consume. That is a bad business if you sized a 15 kW roof on a 8 kW day load “to sell.” Run motors, chillers, and day AC while the sun is up. Idle export is pocket change.
When WAPDA dies: PV watts go to zero on the app, the house is dark unless a separate UPS / genset exists. A cheap UPS on the fridge is not “hybrid.” Two boxes, two failure modes, still no AC.
Huawei SUN2000 specifics
FusionSolar plant must be created with the installer app, then transferred to the owner. Smart current sensor / meter is how it limits export if the DISCO capped you. LUNA HV packs are not 48 V Nitrox batteries — different voltage, different inverter family. 10-year inverter paper is the reason people pay; board swap in a tehsil is not Huawei’s strength. Skip this box for a shed house.
Growatt MIN vs SPH vs SPF
MIN = on-grid (this page). SPH = hybrid. SPF = off-grid. The sticker is three letters. Shops mix them. If your MIN dies in shed, it is working.
Fronius Primo / Symo
Solar.web is excellent. Primo/Symo without GEN24 backup is on-grid. GEN24 is the hybrid-ish SKU, sometimes on Inverex-channel lists. Do not confuse Fronius (Austria) with Fronus (Pakistan IP65 hybrid).
Faults that are not faults
- Zero output at night — the sun is down.
- Zero output in shed — anti-islanding.
- Clipping at noon — PV array larger than AC rating, by design.
- App offline, LEDs green — dongle / Wi-Fi. House still exporting.