Energy meter or CT is connected with reversed polarity or incorrect orientation. Affects export/import monitoring accuracy. A key field indicator is negative phase power readings (Pa, Pb, or Pc showing negative values) — this means that CT for that phase is reversed. Displayed fault ID: 084.
Common causes
CT clamp fitted in wrong orientation — arrow must point toward the load (consumer unit), not toward the gridMeter input/output wiring reversedCT connected to wrong phase cable (IA to L2 instead of L1, etc.)Existing PV inverter rated power not correctly configured
What to check
STEP 1
Check the meter display or iSolarCloud live readings — if Pa, Pb, or Pc shows a negative value, that phase CT is reversed. Physically check the CT clamp on that phase: the arrow must point toward the consumer unit / load side, away from the DNO meter. Flip the CT if wrong.
STEP 2
Check CT phase assignment — CT for IA/IA* must be on L1, IB/IB* on L2, IC/IC* on L3. Also check meter terminal wiring — import and export terminals must not be swapped. If a second (retrofit) PV inverter is installed, check its rated power setting is configured correctly in iSolarCloud.
Escalate if
Meter and CT confirmed correct and phase assignments verified — alarm persists. Contact Sungrow support.
Need full interactive diagnosis?
Faultpath walks you through decision trees, fault codes, and commissioning — built for solar & battery engineers.