What you will see
- Code 17 on a three-phase Sungrow inverter
- One phase in the house is dimmer than the others
- Fault repeats at the same hours every day
Why it happens
When one phase is heavily loaded on the street or in your building, its voltage drops while the others stay up. A three-phase inverter has to stop if the gap is too large.
A loose or burnt contact on one phase gives the same result inside your own board.
Diagram
One weak phase stops the inverter
L1L2L3
Illustration only. Code 17 appears when the gap between phases is too large.
What you can check yourself
- Note which phase lights or appliances seem weak
- Check whether all three phase indicators on the board are lit
- Note the times the fault happens
What not to do
- Do not change the imbalance setting yourself; Sungrow says only within what the power company allows
- Do not swap phases or loads around inside the board
When to call us
- Measure all three phase voltages at the meter and inverter
- Check each phase connection and breaker
- Rebalance house loads across phases
- Prepare a DISCO complaint if the supply is unbalanced
Three-phase supply in Punjab
Unbalanced phases are common in mixed residential and commercial areas of Faisalabad and Lahore. We measure each phase before deciding whether the fix is in your board or with the DISCO.
Send us
fault screenshots and photos of the meter display showing each phase