Delta RPI Series - User Manual

Questions and Answers

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howelltimothySep 6, 2025
Why is my Delta Inverter de-rating?
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  Amanda FriedmanSep 7, 2025
  The Delta Inverter might be de-rating due to several reasons: over temperature, fan failure, the power limit function, power vs. frequency function, P(V) function, low grid voltage, low solar voltage, or high solar voltage. To resolve this, check the installation ambient and environment, inspect the fan(s), check country and grid settings, check the utility frequency and solar voltage on the inverter terminal, and check the reactive power setting.
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Tom McphersonSep 6, 2025
What does 'Grid Quality' mean on my Delta Inverter?
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  Jamie SchultzSep 6, 2025
  The 'Grid Quality' error on your Delta Inverter is caused by Non-linear load in Grid and near to inverter. Grid connection of inverter need to be far away from non-linear load if necessary.
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Jeffrey PerezSep 6, 2025
What does 'DC Current High' mean on my Delta RPI Inverter?
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  Ian EspinozaSep 6, 2025
  A 'DC Current High' error on your Delta Inverter may be caused by a defective switching device in boost, so check all switching device in boost. It may also be caused by a defective driver for boost, so check the driver curcuit for boost inside the inverter. Finally, input current detection circuit malfunction can cause this error, so check input current detection circuit.
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Michelle PowersSep 5, 2025
What does 'HW ZC Fail' mean on my Delta RPI?
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  Katherine WuSep 5, 2025
  A 'HW ZC Fail' error on your Delta Inverter indicates that the detection circuit for synchronal signal malfunction, so check the detection circuit for synchronal signal inside the inverter.
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Lee MooreSep 5, 2025
What does 'HW AC OCR' mean on my Delta RPI?
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  James HensonSep 5, 2025
  A 'HW AC OCR' error on your Delta Inverter can be caused by large Grid harmonics, so check the utility waveform. Grid connection of inverter need to be far away from non-linear load if necessary. It may also be caused by a defective switching device, so check all switching devices in inverter stage. Finally, a detection circuit malfunction could be the reason; in that case, check the detection circuit inside the inverter.
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Emily FryeSep 5, 2025
What does 'HW CT C Fail' mean on my Delta RPI Inverter?
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  Nicole GarciaSep 5, 2025
  A 'HW CT C Fail' error on your Delta Inverter may be caused by a broken test current loop, so check the connection of WC3 to CNC16. It may also indicate that CSC3 is defective, so replace CSC3 with new one. Finally, a detection circuit malfunction could be the reason; in that case, check the detection circuit inside the inverter.
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Mary ChandlerSep 4, 2025
What does 'HW CT B Fail' mean on my Delta Inverter?
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  Jesse DawsonSep 4, 2025
  A 'HW CT B Fail' error on your Delta Inverter could be caused by a broken test current loop, so check the connection of WC3 to CNC16. It may also indicate that CSC2 is defective, so replace CSC2 with new one. Finally, a detection circuit malfunction could be the reason; in that case, check the detection circuit inside the inverter.
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James CraigAug 25, 2025
What to do if my Delta RPI shows 'No Grid'?
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  Kathy JohnsonAug 25, 2025
  If your Delta Inverter displays a 'No Grid' error, it could be due to the AC breaker being off. In this case, switch on the AC breaker. Alternatively, there might be a disconnection in the AC plug. Ensure the AC plug is correctly connected to the inverter.
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Mr. Christian ParkerSep 4, 2025
What does 'AC Current High' mean on my Delta RPI?
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  huntcathySep 4, 2025
  A 'AC Current High' error on your Delta Inverter can happen if surge occurs during operation. It may also be caused by a defective driver for the inverter stage, so check the driver circuit in inverter stage. Another cause may be a defective switching device, so check all switching devices in inverter stage. Finally, a detection circuit malfunction could be the reason; in that case, check the detect circuit inside the inverter.
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emilyturnerSep 3, 2025
What does 'HW Bus OVR' mean on my Delta Inverter?
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  juliadawsonSep 3, 2025
  A 'HW Bus OVR' error on your Delta Inverter may be caused by a defective driver for boost, so check the driver circuit for boost inside the inverter. It may also be caused by the Voc of PV array being over 1000Vdc, so modify the solar array setting, and make the Voc less than 1000Vdc. Surge may occur during operation. Finally, a detection circuit malfunction could be the reason; in that case, check the detection circuit inside the inverter.

Delta RPI Series Specifications

General

Efficiency	Up to 98.8% (depending on model)
Frequency	50 Hz / 60 Hz
Model	RPI Series
Type	Inverter
Protection Rating	IP65
Cooling	Natural convection
Category	Inverter
Cooling Method	Natural convection
Dimensions	Varies by model
Weight	Varies by model
Protection Features	Overvoltage, Short Circuit