FAQ
TL;DR: On an 8-panel string, expect about 240 V DC (8×30 V). "The inverter would report 'Fault'." Check the DC isolator, measure string voltage, and call the installer. [Elektroda, marcinbbb, post #18349178]
Why it matters: This FAQ helps new PV owners fix a non-starting 2.5 kW inverter and read OTUS 3 meters to avoid downtime and billing surprises.
Quick Facts
- Startup: Grid-tied inverters should start immediately after switching on; there’s no internal battery to “charge.” [Elektroda, marcinbbb, post #18349001]
- Expected DC string: Approx. 240 V for 8 panels (~30 V each). Measure with a multimeter; turn off the DC switch first. [Elektroda, marcinbbb, post #18349178]
- GoodWe behavior: If panels are connected, it should show a “Fault,” not stay blank. [Elektroda, marcinbbb, post #18349178]
- OTUS 3 meter: 1.8.0/2.8.0 are totals; 1.8.0.1/2.8.0.1 show last month’s consumption/export. [Elektroda, sq5lc, post #18381760]
- Billing: ≤10 kW prosumers get 0.8× credit on exports with annual balancing. [Elektroda, Leon444, post #18381998]
Why won’t my new 2.5 kW PV inverter start on a cloudy day?
Clouds don't stop startup. Inverters start when PV DC and the grid are present. There is no internal battery. Confirm the DC isolator at the bottom is ON. Verify protections in the security box are ON. If the display stays blank, call the installer. [Elektroda, marcinbbb, post #18349001]
How long does an inverter need to “charge” before first start?
It doesn't. Grid-tied inverters have no battery to charge. They should start immediately after switching on. If it won't start, suspect wiring, disconnects, or protections. Ask the installer to commission and check it. [Elektroda, marcinbbb, post #18349001]
What DC voltage should I see from 8 panels in one string?
Expect about 240 V DC on eight panels in series. As noted, it “should be around 8×30 V = 240 V.” Set your multimeter to a suitable DC range. Turn the DC switch off before unplugging connectors. Near-zero or much lower voltage suggests an open connection. [Elektroda, marcinbbb, post #18349178]
How do I safely check if my PV string is delivering voltage?
- Turn the PV DC switch OFF.
- Disconnect the roof PV cables and measure DC voltage with a multimeter.
- Reconnect, turn the DC switch ON, and review the reading.
Tip: “Before unplugging the cables, switch the DC switch.” [Elektroda, marcinbbb, post #18349178]
Could a wiring fault or low PV voltage stop the inverter from waking up?
Yes. A bad connection in a distribution/combiner box can block startup. In this case, a faulty box caused the issue. The fitter corrected the connection and the system worked. This failure can mimic low or zero PV voltage at the inverter. [Elektroda, bioton1987, post #18381750]
My GoodWe inverter display is blank — what should I check first?
If panels were connected correctly, GoodWe would report “Fault.” A blank screen suggests no PV DC is reaching the inverter. Measure the string voltage (about 240 V for eight panels). Turn the DC switch off before unplugging. Then call the crew to fix it. [Elektroda, marcinbbb, post #18349178]
What do the OTUS 3 meter codes 1.8.0, 1.8.0.1, 2.8.0, 2.8.0.1 mean?
1.8.0 is total grid consumption. 2.8.0 is total energy delivered to the grid. 1.8.0.1 and 2.8.0.1 show last month’s consumption and export. In G11, 1.8.0.2 will appear in the following month. [Elektroda, sq5lc, post #18381760]
Why does my inverter show 19 kWh produced but the meter shows only 10 kWh exported?
The inverter counts all PV generation. The bidirectional meter counts only exported energy. The 9 kWh difference was self-consumed before the meter. Household loads use PV first, then export the surplus. This is normal behavior. [Elektroda, Leon444, post #18381906]
If I used 160 kWh and exported 10 kWh, what will I be billed for?
For ≤10 kW systems, exported energy offsets part of consumption. In the example, you’d be billed for 152 kWh. That equals 160 minus an 8 kWh credit from 10 kWh exported. This matches the forum guidance. [Elektroda, sq5lc, post #18381941]
Do my PV export credits carry over to future months?
Yes. Prosumer balancing is settled across the year. You pay for what remains after applying the 0.8 factor to exports. Surplus in later months offsets earlier consumption within that year. Check your annual statement. [Elektroda, Leon444, post #18381998]
Is my 8‑panel array wired as one string or two?
From the photos discussed, users identified one string. There was one arrester, a two‑pole protection, and a double‑pole break. Two wires from panels feed the inverter’s single PV input. That indicates a single string layout. [Elektroda, theo33, post #18353403]
What was the final fix for the non-starting inverter in this thread?
Faulty distribution boxes were supplied. One had a bad internal connection. The installer corrected it, and the inverter started. Everything worked afterwards, confirming a connection fault. [Elektroda, bioton1987, post #18381750]
