Delta RPI Home Series Solar Inverter faults
The Delta RPI Home Series range of solar inverters can develop a number of different faults, when a fault is present an error message will be displayed on the screen. Below is a list of error messages, explanations on the error or fault and a list of actions to take to resolve the issue.
If you have one of the error or fault messages below we recommend you follow the listed actions to take to remove the fault before contacting a company who can help you further such as Gold Coast Solar Power Solutions.
Delta RPI – M Series inverter faults
| Message | Possible Cause | Action |
|---|---|---|
| AC Freq High | 1. Actual utility frequency is over the OFR setting 2. Incorrect country setting 3. Detection circuit malfunction | 1. Check the utility frequency on the inverter terminal 2. Check country setting 3. Check the detection circuit inside the inverter |
| AC Freq Low | 1. Actual utility frequency is under the UFR setting 2. Incorrect country or Grid setting 3. Detection circuit malfunction | 1. Check the utility frequency on the inverter terminal 2. Check country & Grid setting 3. Check the detection circuit inside the inverter |
| Grid Quality | Non-linear load in Grid and near to inverter | Grid connection of inverter need to be far away fromnon-linear load if necessary |
| HW Connect Fail | 1. Wrong connection in AC plug 2. Detection circuit malfunction | 1. Check the AC connection, must accords to manual 2. Check the detection circuit inside the inverter |
| No Grid | 1. AC breaker is OFF 2. Disconnect in AC plug | 1. Switch on AC breaker 2. Check the connection in AC plug and make sure it connects to inverter |
| AC Volt Low | 1. Actual utility voltage is under the UVR setting 2. Incorrect country or Grid setting 3. Wrong connections in AC plug 4. One or more internal fuses are broken 5. Detection circuit malfunction | 1. Check the utility voltage connection to the inverter terminal 2. Check country & Grid setting 3. Check the connection in AC plug 4. Replace fuses (FUC1-3) and check all switching devices in boost & inverter stages 5. Check the detection circuit inside the inverter |
| AC Volt High | 1. Actual utility voltage is over the OVR setting 2. Utility voltage is over the Slow OVR setting during operation 3. Incorrect country or Grid setting 4. Detection circuit malfunction | 1. Check the utility voltage on the inverter terminal 2. Check the utility voltage on the inverter terminal 3. Check country & Grid setting 4. Check the detection circuit inside the inverter |
| Solar1 High | 1. Actual Solar1 voltage is over 1000Vdc 2. Detection circuit malfunction | 1. Modify the solar array setting, and make the Voc less than 1000Vdc 2. Check the detection circuit inside the inverter |
| Solar2 High | 1. Actual Solar2 voltage is over 1000Vdc 2. Detection circuit malfunction | 1. Modify the solar array setting, and make the Voc less than 1000Vdc 2. Check the detection circuit inside the inverter |
| Insulation | 1. PV array insulation fault 2. Large PV array capacitance between Plus to Ground or Minus to Ground or both. 3. Detection circuit malfunction | 1. Check the insulation of Solar inputs 2. Check the capacitance, dry PV panel if necessary 3. Check the detection circuit inside the inverter |
| Solar1 Low | 1. Actual Solar1 voltage is under the limit 2. Some devices were damaged inside the inverter if the actual Solar1 voltage is close to “0” 3. Detection circuit malfunction | 1. Check the Solar1 voltage connection to the inverter terminal 2. Check all switching devices in boost1 3. Check the detection circuit inside the inverter |
| Solar2 Low | 1. Actual Solar2 voltage is under the limit 2. Some devices were damaged inside the inverter if the actual Solar2 voltage is close to “0” 3. Detection circuit malfunction | 1. Check the Solar2 voltage connection to the inverter terminal 2. Check all switching devices in boost2 3. Check the detection circuit inside the inverter |
| HW FAN | 1. One or more fans are locked 2. One or more fans are defective 3. One ore more fans are disconnected 3. Detection circuit malfunction | 1. Remove the object that stuck in the fan(s) 2. Replace the defective fan(s) 3. Check the connections of all fans 4. Check the detection circuit inside the inverter |
| HW DC Injection | 1. Utility waveform is abnormal 2. Detection circuit malfunction | 1. Check the utility waveform. Grid connection of inverter need to be far away from non-linear load if necessary 2. Check the detection circuit inside the inverter |
| Temperature High | 1. The ambient is over 60℃ (The installation is abnormal) 2. Detection circuit malfunction | 1. Check the installation ambient and environment 2. Check the detection circuit inside the inverter |
| HW NTC1 Fail | 1. Ambient temperature >90℃ or <-30℃ 2. Detection circuit malfunction | 1. Check the installation ambient and environment 2. Check the detection circuit inside the inverter (RTM1) |
| Temperature Low | 1. Ambient temperature is <-30℃ 2. Detection circuit malfunction | 1. Check the installation ambient and environment 2. Check the detection circuit inside the inverter (RTG1) |
| HW NTC4 Fail | 1. Ambient temperature >90℃ or <-30℃ 2. Detection circuit malfunction | 1. Check the installation ambient and environment 2. Check the detection circuit inside the inverter (RTH1) |
| HW DSP ADC1 | 1. Insufficient input power 2. Auxiliary power circuitry malfunction 3. Detection circuit malfunction | 1. Check the input voltage, must > 150Vdc 2. Check the auxiliary circuitry inside the inverter 3. Check the detection circuit inside the inverter |
| HW DSP ADC2 | 1. Insufficient input power 2. Auxiliary power circuitry malfunction 3. Detection circuit malfunction | 1. Check the input voltage, must > 150Vdc 2. Check the auxiliary circuitry inside the inverter 3. Check the detection circuit inside the inverter |
| HW DSP ADC3 | 1. Insufficient input power 2. Auxiliary power circuitry malfunction 3. Detection circuit malfunction | 1. Check the input voltage, must > 150Vdc 2. Check the auxiliary circuitry inside the inverter 3. Check the detection circuit inside the inverter |
| HW Red ADC1 | 1. Insufficient input power 2. Auxiliary power circuitry malfunction 3. Detection circuit malfunction | 1. Check the input voltage, must > 150Vdc 2. Check the auxiliary circuitry inside the inverter 3. Check the detection circuit inside the inverter |
| HW Red ADC2 | 1. Insufficient input power 2. Auxiliary power circuitry malfunction 3. Detection circuit malfunction | 1. Check the input voltage, must > 150Vdc 2. Check the auxiliary circuitry inside the inverter 3. Check the detection circuit inside the inverter |
| HW Efficiency | 1. The calibration is incorrect 2. Current feedback circuit is defective | 1. Check the accuracy of current and power 2. Check the current feedback circuit inside the inverter |
| HW COMM2 | 1. Red. CPU is idling 2. The communication connection is disconnected | 1. Check reset and crystal in Red. CPU 2. Check the connection between Red. CPU and DSp |
| HW COMM1 | 1. DSP is idling 2. The communication connection is disconnected 3. The communication circuit malfunction | 1. Check reset and crystal in DSP 2. Check the connection between DSP and COMM 3. Check the communication circuit |
| Ground Current | 1. PV array insulation fault 2. Large PV array capacitance between Plus to Ground or Minus to Ground 3. Either side of boost driver or boost choke malfunction 4. Detection circuit malfunction | 1. Check the insulation of Solar inputs 2. Check the capacitance (+ <-> GND & – <-> GND), must < 2.5uF. Install a external transformer if necessary 3. Check boost driver & boost choke 4. Check the detection circuit inside the inverter |
| HW Connect Fail | 1. Power line is disconnected inside the inverter 2. Current feedback circuit is defective | 1. Check the power lines inside the inverter 2. Check the current feedback circuit inside the inverter |
| RCMU Fail | 1. RCMU is disconnected 2. Detection circuit malfunction | 1. Check the RCMU connection inside the inverter 2. Check the detection circuit inside the inverter |
| Relay Test Short | 1. One or more relays are sticking 2. The driver circuit for the relay malfunction | 1. Replace the defective relay(s) 2. Check the driver circuit inside the inverter |
| Relay Test Open | 1. One or more relays are abnormal 2. The driver circuit for the relay malfunction 3. The detection accuracy is not correct for Vgrid and Vout | 1. Replace the defective relay(s) 2. Check the driver circuit inside the inverter 3. Check the Vgrid and Vout voltage detection accuracy |
| Bus Unbalance | 1. Not totally independent or parallel between inputs 2. PV Array short to Ground 3. Driver for boost is defective or disconnected 4. Detection circuit malfunction | 1. Check the inputs connections 2. Check the PV Array insulation 3. Check the driver circuit for boost inside the inverter 4. Check the detection circuit inside the inverter |
| HW Bus OVR | 1. Driver for boost is defective 2. Voc of PV array is over 1000Vdc 3. Surge occurs during operation 4. Detection circuit malfunction | 1. Check the driver circuit for boost inside the inverter 2. Modify the solar array setting, and make the Voc less than 1000Vdc 3. N/A 4. Check the detection circuit inside the inverter |
| AC Current High | 1. Surge occurs during operation 2. Driver for inverter stage is defective 3. Switching device is defective 4. Detection circuit malfunction | 1. N/A 2. Check the driver circuit in inverter stage 3. Check all switching devices in inverter stage 4. Check the detect circuit inside the inverter |
| HW CT A Fail | 1. Test current loop is broken 2. CSC1 is defective 3. Detection circuit malfunction | 1. Check the connection of WC3 to CNC16 2. Replay CSC1 with new one 3. Check the detection circuit inside the inverter |
| HW CT B Fail | 1. Test current loop is broken 2. CSC2 is defective 3. Detection circuit malfunction | 1. Check the connection of WC3 to CNC16 2. Replace CSC2 with new one 3. Check the detection circuit inside the inverter |
| HW CT C Fail | 1. Test current loop is broken 2. CSC3 is defective 3. Detection circuit malfunction | 1. Check the connection of WC3 to CNC16 2. Replace CSC3 with new one 3. Check the detection circuit inside the inverter |
| HW AC OCR | 1. Large Grid harmonics 2. Switching device is defective 3. Detection circuit malfunction | 1. Check the utility waveform. Grid connection of inverter need to be far away from non-linear load if necessary 2. Check all switching devices in inverter stage 3. Check the detection circuit inside the inverter |
| HW ZC Fail | The detection circuit for synchronal signal malfunction | Check the detection circuit for synchronal signal inside the inverter |
| DC Current High | 1. Switching device in boost is defective 2. Driver for boost is defective 3. Input current detection circuit malfunction | 1. Check all switching device in boost 2. Check the driver curcuit for boost inside the inverter 3. Check input current detection circuit |
Delta RPI – H Series inverter faults
| Message | Possible cause | Action |
|---|---|---|
| E01: Grid Freq Over Rating | 1. Actual utility frequency is over the OFR setting 2. Incorrect country setting 3. Detection circuit malfunction | 1. Check the utility frequency on the inverter terminal 2. Check country setting 3. Check the detection circuit inside the inverter |
| E02: Grid Freq Under Rating | 1. Actual utility frequency is under the UFR setting 2. Incorrect country or Grid setting 3. Detection circuit malfunction | 1. Check the utility frequency on the inverter terminal 2. Check country & Grid setting 3. Check the detection circuit inside the inverter |
| E07:Grid Quality | Non-linear load in Grid and near to inverter | Grid connection of inverter need to be far away from non-linear load if necessary |
| E09: No Grid | 1. AC breaker is OFF 2. Disconnect in AC plug 3. Internal fuses are broken | 1. Switch on AC breaker 2. Check the connection in AC plug and make sure it connects to inverter 3. Replace fuses and check all switching devices in boost & inverter stages |
| E10: Grid Volt Under Rating | 1. Actual utility voltage is under the UVR setting 2. Utility voltage is under the Slow UVR setting during operation 3. Incorrect country or Grid setting 4. Detection circuit malfunction | 1.&2. Check the utility voltage connection to the inverter terminal.3. Check country & Grid setting 4. Check the detection circuit inside the inverter |
| E11: Grid Volt Over Rating | 1. Actual utility voltage is over the OVR setting 2. Utility voltage is over the Slow OVR setting during operation 3. Incorrect country or Grid setting 4. Detection circuit malfunction | 1.&2. Check the utility voltage on the inverter terminal3. Check country & Grid setting 4. Check the detection circuit inside the inverter |
| E13: Slow Over Voltage Range | 1. Actual utility voltage is over the OVR setting 2. Incorrect country or Grid setting 3. Detection circuit malfunction | 1. Check the utility voltage on the inverter terminal 2. Check country & Grid setting 3. Check the detection circuit inside the inverter |
| E26:Slow Over Frequency Range | 1. Actual utility frequency is over the OFR setting 2. Incorrect country or grid setting 3. Detection circuit malfunction | 1. Check the utility frequency on the inverter terminal 2. Check country setting 3. Check the detection circuit inside the inverter |
| E27:Slow Under Frequency Range | 1. Actual utility frequency is under the UFR setting 2. Incorrect country or Grid setting 3. Detection circuit malfunction | 1. Check the utility frequency on the inverter terminal 2. Check country & Grid setting 3. Check the detection circuit inside the inverter |
| E28: Slow Under Voltage Range | 1. Actual utility voltage is under the UVR setting 2. Incorrect country or Grid setting 3. Detection circuit malfunction | 1. Check the utility voltage on the inverter terminal 2. Check country & Grid setting 3. Check the detection circuit inside the inverter |
| E30: DC Volt Over Rating | 1. Actual Solar1 voltage is over 550Vdc (RPI-H3) or 1000Vdc (RPI-H5) 2. Detection circuit malfunction | 1. Modify the solar array setting, and make the Voc less than 550Vdc (RPI-H3) or 1000Vdc (RPI-H5) 2. Check the detection circuit inside the inverter |
| E32: L/N Reversed | 1. Incorrect AC wiring 2. Incorrect AC connection setting | 1. Check if brown wire is connected to Line and blue wire is connected to Neutral. 2. Check display “AC configurat.” setting |
| A01: DC Offset Over Rating | 1. Utility waveform is abnormal 2. Detection circuit malfunction | 1. Check the utility waveform. Grid connection of inverter need to be far away from non-linear load if necessary 2. Check the detection circuit inside the inverter |
| A05: NTC Over Temp | 1. The ambient temp. is over 60℃ 2. Detection circuit malfunction | 1. Check the installation ambient and environment 2. Check the detection circuit inside the inverter |
| A06: Inside NTC Circuit Fail | 1. Ambient temp. >100℃ or <-24℃ 2. Detection circuit malfunction | 1. Check the installation ambient and environment 2. Check the detection circuit inside the inverter |
| A08: Heat Sink NTC1 Fail | 1. Boost heat sink temp. >100℃ or <-24℃ 2. Detection circuit malfunction | 1. Check the installation ambient and environment 2. Check the detection circuit inside the inverter. |
| A09: Heat Sink NTC2 Fail | 1. Inverter heat sink temp. >100℃ or <-24℃ 2. Detection circuit malfunction | 1. Check the installation ambient and environment 2. Check the detection circuit inside the inverter |
| A15:DSP ADC Vgrid/Iout Fail | 1. Auxiliary power circuitry malfunction 2. Detection circuit malfunction | 1. Check the auxiliary circuitry inside the inverter 2. Check the detection circuit inside the inverter |
| A16:DSP ADC Vin/Vbus Fail | 1. Auxiliary power circuitry malfunction 2. Detection circuit malfunction | 1. Check the auxiliary circuitry inside the inverter 2. Check the detection circuit inside the inverter |
| A17:DSP ADC Iin/Iboost Fail | 1. Auxiliary power circuitry malfunction 2. Detection circuit malfunction | 1. Check the auxiliary circuitry inside the inverter 2. Check the detection circuit inside the inverter |
| A18:RED. ADC Vgrid Fail | 1. Auxiliary power circuitry malfunction 2. Detection circuit malfunction | 1. Check the auxiliary circuitry inside the inverter 2. Check the detection circuit inside the inverter |
| A19:DSP ADC Iout_dc Fail | 1. Auxiliary power circuitry malfunction 2. Detection circuit malfunction | 1. Check the auxiliary circuitry inside the inverter 2. Check the detection circuit inside the inverter |
| A20: Efficiency Inconsistent | 1. The calibration is incorrect 2. Current feedback circuit is defective | 1. Check the accuracy of current and power 2. Check the current feedback circuit inside the inverter |
| A22: Internal Comm Fault_R | 1. DSP is idling 2. The communication connection is disconnected 3. The communication circuit malfunction | 1. Check reset and crystal in DSP 2. Check the connection between DSP and COMM 3. Check the communication circuit |
| A24: Residual Curr Over Rating | 1. PV array insulation fault 2. Large PV array capacitance between Plus to Ground or Minus to Ground 3. Either side of boost driver or boost choke malfunction 4. Detection circuit malfunction | 1. Check the insulation of Solar inputs 2. Check the capacitance (+ <-> GND & – <-> GND), must < 2.5uF. Install an external transformer if necessary 3. Check boost driver & boost choke 4. Check the detection circuit inside the inverter |
| A25: Ground Fault | 1. PV array insulation fault 2. Large PV array capacitance between Plus to Ground or Minus to Ground or both. 3. Detection circuit malfunction | 1. Check the insulation of Solar inputs 2. Check the capacitance, dry PV panel if necessary 3. Check the detection circuit inside the inverter |
| A27: RCMU Circuit Fail | 1. RCMU is disconnected 2. Detection circuit malfunction | 1. Check the RCMU connection inside the inverter 2. Check the detection circuit inside the inverter |
| A28: Relay Short | 1. One or more relays are sticking 2. The driver circuit for the relay malfunction | 1. Replace the defective relay(s) 2. Check the driver circuit inside the inverter |
| A29: Relay Open | 1. One or more relays are abnormal 2. The driver circuit for the relay malfunction 3. The detection accuracy is not correct for Vgrid and Vout | 1. Replace the defective relay(s) 2. Check the driver circuit inside the inverter 3. Check the Vgrid and Vout voltage detection accuracy |
| A30: Bus Unbalance | 1. Not totally independent or parallel between inputs 2. PV Array short to Ground 3. Driver for boost is defective or disconnected 4. Detection circuit malfunction | 1. Check the inputs connections 2. Check the PV Array insulation 3. Check the driver circuit for boost inside the inverter 4. Check the detection circuit inside the inverter |
| A31: Bus_P Over Volt Rating | 1. Driver for boost is defective 2. Voc of PV array is over 550Vdc (RPI-H3) or 1000Vdc (RPI-H5) 3. Surge occurs during operation 4. Detection circuit malfunction | 1. Check the driver circuit for boost inside the inverter 2. Modify the solar array setting, and make the Voc less than 550Vdc (RPI-H3) or 1000Vdc (RPI-H5) 3. N/A 4. Check the detection circuit inside the inverter |
| A33: Bus_N Over Volt Rating | 1. Driver for boost is defective 2. Voc of PV array is over 550Vdc (RPI-H3) or 1000Vdc (RPI-H5) 3. Surge occurs during operation 4. Detection circuit malfunction | 1. Check the driver circuit for boost inside the inverter 2. Modify the solar array setting, and make the Voc less than 550Vdc (RPI-H3) or 1000Vdc (RPI-H5) 3. N/A 4. Check the detection circuit inside the inverter |
| A35: Bus Volt Over Rating | 1. Driver for boost is defective 2. Voc of PV array is over 550Vdc (RPI-H3) or 1000Vdc (RPI-H5) 3. Surge occurs during operation 4. Detection circuit malfunction | 1. Check the driver circuit for boost inside the inverter 2. Modify the solar array setting, and make the Voc less than 550Vdc (RPI-H3) or 1000Vdc (RPI-H5) 3. N/A 4. Check the detection circuit inside the inverter |
| A36:Output Curr Transient Over | 1. Surge occurs during operation 2. Driver for inverter stage is defective 3. Switching device is defective 4. Detection circuit malfunction | 1. N/A 2. Check the driver circuit in inverter stage 3. Check all switching devices in inverter stage 4. Check the detect circuit inside the inverter |
| A37: AC Curr Over Rating | Detection circuit malfunction | Check the detect circuit inside the inverter |
| A42: CT Current Sensor Fail | 1.Inverter choke Fail 2.Output Filter Fail 3. Detection circuit malfunction | 1. Check Inverter choke inductance. 2. Check output filter capacitance. 3. Check the detection circuit inside the inverter |
| A45: HW OOCP | 1. WB1 WB2 misconnection. 2. Detection circuit malfunction | 1. Check the connection of WB1 and WB2. 2. Check the detection circuit inside the inverter |
| A50:Zero Cross Circuit Fail | The detection circuit for synchronal signal malfunction | Check the detection circuit for synchronal signal inside the inverter |
| A56:Hardware Incompatibility | 1. HW power rating incorrect | 1. Check comm. HW power rating info. |
| A60: DC Curr Over Rating | 1. Switching device in boost is defective 2. Driver for boost is defective 3. Input current detection circuit malfunction | 1. Check all switching device in boost 2. Check the driver circuit for boost inside the inverter 3. Check input current detection circuit |
| A70: DC Curr Transient Over | 1. Switching device in boost is defective 2. Driver for boost is defective 3. Input current detection circuit malfunction | 1. Check all switching device in boost 2. Check the driver circuit for boost inside the inverter 3. Check input current detection circuit |
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