What you will see
- Inverter stops in the evening or when heavy loads start
- iSolarCloud shows Grid Undervoltage with code 4 or 5
- Lights dim in the house at the same time
Why it happens
At peak load the voltage at the end of a long line can fall below the inverter's safe range, so it stops feeding power until it recovers.
A loose AC connection or tired breaker can cause the same reading at the inverter even when the street voltage is fine.
Diagram
Voltage dips, inverter waits
Normal supply
GridSteady
→InverterFeeding
Peak hours or motor start
GridDips
→InverterStopped
Codes:
45
What you can check yourself
- Note the time and what was running when it tripped
- Check if lights dim or fans slow down at the same time
- Check that the AC breaker for the inverter is fully ON and not warm or discoloured from the outside
What not to do
- Do not open the distribution board to tighten connections yourself
- Do not add a stabilizer in front of an on-grid inverter
When to call us
- Measure voltage at meter and inverter during the dip
- Check AC terminals and breaker for loose or heat-damaged contacts
- Check cable size for the inverter's output
- Log readings for a DISCO complaint if the supply is the cause
Low voltage at peak hours
Low evening voltage is a familiar problem on overloaded lines around Faisalabad and Lahore. We can check whether it is the supply or your own wiring before you contact FESCO or LESCO.
Send us
fault screenshots with times, what loads were running, and a photo of the inverter breaker