Solar Just Commissioned And Signed Off But Export Callback: Post-Service Decision Tree

Why this matters

A system that passed commissioning yesterday, was signed off, and is now being reported as "not exporting" puts the operator in a sensitive position. The customer remembers a tech being there hours ago saying everything was fine, so the next conversation has to start from credibility, not from a clean diagnostic slate. Most post-commissioning export callbacks resolve to one of four causes: the utility has not energized the meter, a permission-to-operate (PTO) condition was not actually met, a configuration limit is throttling export, or grid-side conditions changed after the tech left. This tree walks the right sequence and protects the customer relationship while the diagnosis runs.

Section 1: Confirm what the customer is actually seeing

Before treating this as a fault, confirm the report. Customers commissioned the day before often interpret the dashboard incorrectly.

Ask and verify:

• Is the inverter producing AC and the customer is seeing zero on the dashboard? (A monitoring delay or gateway pairing issue is common in the first 48 hours.)
• Is the inverter not producing AC at all? (A real fault.)
• Is the customer seeing production but no grid export, even though loads are clearly below production? (A real export issue.)
• Is the customer seeing import from grid all day on a sunny day? (Either no production or a CT polarity reversal that is showing production as import.)

Each of those is a different branch.

Section 2: Verify utility status (PTO and meter)

In many jurisdictions, the system can pass commissioning and be physically capable of producing while the utility has not yet granted permission to operate or has not yet installed the bi-directional meter.

Verify:

• PTO documentation. If PTO has not been issued, the inverter may have been left in a non-export configuration intentionally, or the system may be producing but the utility meter is not crediting it.
• The meter on the service. Bi-directional, current generation, correct model for the agreement. An older meter without bi-directional capability will treat export as consumption (the customer's bill increases as the system produces).
• Any utility-required external disconnect in the correct state.

If PTO is the blocker, this is not a service event for the array. It is a paperwork status that needs to be communicated to the customer plainly and tracked with the utility.

Section 3: Verify the commissioning configuration was correct

A surprising number of "next day" callbacks trace to a configuration that was left in a commissioning state, not the final operating state.

Common patterns:

• Export limit was set to zero during commissioning to satisfy a temporary utility requirement and never raised to the design value.
• The grid-support profile was set to a generic default for initial connection and never moved to the utility-specific profile.
• The system was placed in a self-consumption-only mode for a hybrid configuration and never switched to export mode after PTO.
• The inverter is on the commissioning firmware and a required production firmware push was missed.

Pull the configuration export from the commissioning visit. Compare against the as-designed values. Any drift between commissioning and operating settings is your finding.

Section 4: Verify grid conditions at the AC terminals

Even on a perfectly commissioned system, grid conditions at the time of commissioning can differ from conditions a day later. A system commissioned at midday with low neighborhood load can run into a high-voltage trip the next morning at the peak of the solar curve when load is light.

Measure at the inverter AC terminals:

• Line voltage across a 30-minute window during the highest expected production period.
• Frequency stability.
• Neutral-to-ground voltage.

Check the inverter event log for any trips since the commissioning visit. The most common post-commissioning trip pattern is a high-voltage disconnect during the production peak that the inverter then keeps cycling through.

If grid voltage is at the upper IEEE 1547 trip band, the fix is on the utility side or in the service drop. The inverter is doing exactly what it is required to do.

Section 5: Verify the interconnection path

Walk the path from the inverter to the meter:

• AC disconnect at the inverter: closed, no fault indicator.
• PV branch breaker at the main panel: closed, in the position required by the 120 percent rule.
• Any external utility disconnect: closed.
• CT or revenue meter sensing: correct polarity, correct direction.

A CT reversed during commissioning will show production as import, which the customer reads as "my system is making my bill worse." This is one of the most common single-cause post-commissioning callbacks and is fast to identify and correct.

Section 6: Customer communication on a next-day callback

The customer's confidence in the install is on the line. Be direct.

Plain framing:

• "Thanks for calling. We just commissioned yesterday, and we want to make sure this is right. Here is what I am seeing from the data so far, and here is what I want to verify on site or with the utility."
• If the cause is PTO: "The system is built and tested, but the utility has not yet enabled the meter to credit your production. Here is the PTO status and what happens next."
• If the cause is a configuration limit: "We found a setting that was left in the commissioning state and not moved to the final operating value. We have corrected that on this visit. Here is what changed."
• If the cause is grid-side: "The grid voltage at your service is at the upper limit, which is causing the inverter to trip to protect itself and the line. We need to coordinate with the utility on that. Here is what we are doing."
• If the cause is a CT reversal: "We found that a sensor was installed reversed, which made the dashboard show your production as consumption. We have corrected it. Going forward, the numbers will be accurate."

Do not blame the previous tech in front of the customer. Document the cause, the fix, and any follow-on internally.

A clean close has the customer confident that the system is producing as designed, the cause is documented, and any utility-side follow-on is owned by someone with a defined next step.

References

• NEC 2023, Article 690 (Solar Photovoltaic Systems).
• NEC 2023, Article 705 (Interconnected Electric Power Production Sources).
• NEC 2023, Article 705.12 (Point of Connection, including the 120 percent rule).
• IEEE 1547-2018, Standard for Interconnection and Interoperability of Distributed Energy Resources with Associated Electric Power Systems Interfaces.
• UL 1741 SB (Supplement B), Inverters, Converters, Controllers and Interconnection System Equipment for Use With Distributed Energy Resources.