FAQ
TL;DR: On 22 kWp with ~80 m of 5×10 mm², expect a voltage drop above 2%; "The inverter may be damaged." For Solis OV-G-V04, verify supply with a loop-impedance test before concluding a bad unit. [Elektroda, theo33, post #19241330]
Why it matters: Grid-trip faults stop production; this FAQ helps Solis 20 kW owners diagnose OV-G-V04 and right-size cabling to avoid downtime.
Quick Facts
- OV-G-V04 signals the grid voltage is too high for the inverter to export. [Elektroda, studniarz, post #19241042]
- At ~22 kW over ~80 m on 10 mm², voltage drop is above 2%, increasing trip risk. [Elektroda, theo33, post #19241330]
- Swap test replicated OV-G-V04 on another system, indicating a faulty inverter. [Elektroda, jedras64, post #19240046]
- Typical PV export current here is ~32 A in summer (~0.32 A/mm² on 10 mm²). [Elektroda, trojan 12, #19258064]
- User guidance: for ~80 m AC, consider 5×25 mm² Cu or 5×35 mm² Al. [Elektroda, noja102, post #19242459]
What does Solis fault OV-G-V04 actually mean?
OV-G-V04 indicates the inverter detects the grid voltage as too high and disconnects for protection. “This message rather says that the network voltage is too high.” Address the cause before restarting generation. [Elektroda, studniarz, post #19241042]
Could my 80 m YKY 5×10 mm² AC cable cause OV-G-V04?
Yes. Long 10 mm² runs increase line impedance and voltage rise during export. For 22 kW over about 80 m, expect a voltage drop above 2%, which narrows protection margins and can trigger trips on OV-G-V04. [Elektroda, theo33, post #19241330]
How do I quickly diagnose OV-G-V04?
- Check if any work occurred along the cable route that could cause damage.
- Inspect connection clamps on both ends for looseness or carbon deposits.
- Measure the AC voltage arriving at the inverter during operation. [Elektroda, kosmos99, post #19239731]
The grid at my inverter reads 236–240 V. Why do I still get OV-G-V04?
A user measured 236–240 V and still saw OV-G-V04. The same inverter produced the fault on another system, indicating an internal inverter issue rather than the grid. When voltage is normal yet the fault persists, suspect the device. [Elektroda, jedras64, post #19241238]
Should I try swapping inverters to confirm the fault?
Yes. Move your Solis to a known‑good installation and observe. In the thread, swapping the inverter to a friend’s plant reproduced OV-G-V04 immediately, confirming an inverter fault rather than site wiring or cable. [Elektroda, jedras64, post #19240046]
What instrument can check if supply impedance is too high?
Use a short‑circuit loop‑impedance meter on the AC feed. It verifies whether supply impedance is acceptable. If readings are good and OV-G-V04 persists, “The inverter may be damaged.” [Elektroda, theo33, post #19241330]
Is aluminum cable acceptable for long PV AC runs?
Yes, where appropriate terminations and rules permit. “All normal power industry … works on aluminum cables. And it works without any problems.” Aluminum helps manage cost and weight on long runs. [Elektroda, retrofood, post #19258015]
What cable size do users recommend for an ~80 m AC run?
One practitioner recommended 5×25 mm² copper or 5×35 mm² aluminum for about 80 m between inverter and meter. This increases headroom by reducing voltage rise under export. [Elektroda, noja102, post #19242459]
How much current does a 20 kW three‑phase inverter export?
Around 32 A under strong sun. “About 32 A flows in the cables in the summer in the sun from PV.” On 10 mm², that is roughly 0.32 A/mm², within typical thermal limits. [Elektroda, trojan 12, #19258064]
Who should adjust inverter grid‑protection settings?
Leave grid parameters to authorized service or installer. As the owner stated, “I need to change something in the settings, but this is the responsibility of the website.” Unauthorized changes can violate local grid codes. [Elektroda, jedras64, post #19240584]
What should I look for at the inverter AC terminals?
Inspect around the AC power connection for suspicious discoloration. Heat marks or darkening can signal poor contact or arcing that increases local impedance and trips protection. [Elektroda, Merio186, post #19240527]
Could recent digging or ground works cause OV-G-V04?
Yes. Damage along the buried cable can increase resistance or cause intermittent faults. Confirm whether any work happened near the cable and inspect the route before deeper tests. [Elektroda, kosmos99, post #19239731]
When does conductor cross‑section matter less?
During low generation, conductor size has limited impact. “At the moment, the production from PV reaches 10% of the maximum power, it does not matter the conductor cross-section (0.32 A/mm²).” Expect fewer voltage‑rise issues in such conditions. [Elektroda, trojan 12, #19258064]
Is copper always better than aluminum for PV AC runs?
Not always. One expert noted that, outside special cases, aluminum dominates. “By far over 90% of the applications are aluminum.” Use proper terminations and follow site‑specific requirements. [Elektroda, retrofood, post #19258292]
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