Sungrow KTL-M Solar InverterSungrow is now the world’s largest manufacturer of solar inverters with an inverter range that has proven to be quite reliable. Its Sungrow KTL-M Solar Inverter has a 10-year warranty on parts and 5 years on labor is offered at a reasonable price.

If an issue on this inverter comes up, we have put together a list of faults and solutions. The list provides the fault, its cause and troubleshooting procedures from Sungrow KTL-M Solar Inverter users manual.

When a fault occurs on the Sungrow KTL-M Solar Inverter, the Fault light will be on. It will also display the fault on the LCD display panel.  Now, should you decide to follow the recommended actions, please note that safety measures should be observed to avoid any risk of injury. Otherwise, contact a qualified electrician for assistance.

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Fault

Cause

Troubleshooting

Vdc1high The DC input voltage
of PV1 exceeds the
allowable threshold.
1. Rotate the optional DC switch to the “OFF” position immediately.
2. Measure the open circuit voltage of PV1 string again. Decrease the number of PV modules in PV1 string if the voltage measured is not permissible.
3. Reconnect the DC cables to the inverter and start up the inverter.
4. If the fault still exists, contact Sungrow Service Dept.
Vdc2high The DC input voltage
of PV2 exceeds the
allowable threshold.
1. Rotate the optional DC switch to the “OFF” position immediately.
2. Measure the open circuit voltage of PV2 strings again. Decrease the number of PV modules in PV2 string if the voltage measured is not permissible.
3. Reconnect the DC cables to the inverter and start up the inverter.
4. If the fault still exists, contact Sungrow Service Dept.
Idc1high The DC input current
of PV1 exceeds the
allowable threshold.
1. Rotate the optional DC switch to the “OFF” position immediately.
2. Measure the short-circuit current of PV1 string again. Decrease the number of PV1 strings in serial if the current measured is not permissible.
3. Reconnect the DC cables to the inverter and start up the inverter.
4. If the fault still exists, contact Sungrow Service Dept.
Idc2high The DC input current
of PV2 exceeds the
allowable threshold.
1. Rotate the optional DC switch to the “OFF” position immediately.
2. Measure the short-circuit current of PV2 strings again. Decrease the number of PV2 strings in serial if the current measured is not permissible.
3. Reconnect the DC cables to the inverter and start up the inverter.
4. If the fault still exists, contact Sungrow Service Dept.
Vac-low The grid voltage falls below the allowable minimum grid voltage threshold of the installation country. 1. Check the voltage of the grid.
2. If the grid voltage exceeds the permissible range of inverter protective parameters, ask the utility grid company for solution.
3. If the grid voltage is within the permissible range, contact Sungrow Service Dept.
Vac-high The grid voltage exceeds the allowable maximum threshold of the installation country.
F-fault The grid frequency exceeds the permissible range. 1. Check the frequency of the grid.
2. If the grid frequency exceeds the permissible range of inverter protective parameters, ask the utility grid company for solution.
3. If the grid voltage is within the permissible range, contact Sungrow Service Dept.
No-grid Grid is not present. 1. Check whether the AC circuit breaker is triggered.
2. Check whether all AC cables are firmly connected.
3. Check whether the grid is out of service
4. If all conditions are OK and this malfunction still occurs in the LCD screen, contact Sungrow Service Dept. for solution.
Temp-flt The ambient temperature of the inverter is too high. 1. The installation site may not be optimal.
2. Too much dirt on the fans.
3. Check the fans for abnormal noise. Replace the broken fan if necessary.
4. Heat sink is covered.
5. If the fault still exists, contact Sungrow Service Dept.
Samp-flt Malfunction of the sample circuit. Contact Sungrow Service Dept. for solution.
Earth-flt Earth fault. 1. Check the grounding connection of the Pv arrays.
2. Check the grounding/PE connection of the inverter.
3. Contact Sungrow Service Dept. for solution.
Bus-high The bus voltage exceeds the limit. 1. Rotate the optional DC switch to the “OFF” position immediately.
2. Measure the short-circuit current of PV1 string again. Decrease the number of PV1 strings in serial if the current measured is not permissible.
3. Reconnect the DC cables to the inverter and start up the inverter.
4. If the fault still exists, contact Sungrow Service Dept.
Relay-ft Malfunction of the inverter relay. Contact Sungrow Service Dept. for solution.
RISO-ft Resistance between the PV panels and the earth is too low. Rain or moisture may result in this fault. Wait a moment for inverter recovery.
lac-high The AC output current is too high. Power grid exception may cause this fault. Wait a moment for inverter recovery. If the fault occurs repeatedly, contact Sungrow Service Dept. for solution.
Fan-flt Fan’s defect. Contact Sungrow Service Dept. for solution.
DC inject DC injection of inverter output current is too high. Contact Sungrow Service Dept. for solution.
HRDW Pro Malfunction of hardware resulted from overvoltage of the bus, over-current of the output or input current. Wait a moment for inverter recovery. If the fault continues for an hour, contact Sungrow Service Dept.
Acce-flt The PV configuration mode set is not in accordance with the configuration of the actual electrical connection. 1. Disconnect the inverter.
2. Re-select the PV configuration mode or re-connect the DC inputs.
Com-err LCD has failed to communicate with DSP for over 20 times. 1. If this malfunction happens, wait for a while and observe whether the fault can be cleared by the inverter itself.
2. Perform the “Stop” command in the LCD display.
3. Perform the “Start” command to restart the inverter.
4. If the fault still exists, contact Sungrow Service Dept.

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For the full detailed information you can check the Sungrow KTL-M Solar Inverter manual’s Troubleshooting section.  Should you follow the troubleshooting steps above but the issue is not fixed on your Sungrow KTL-M solar inverter check if it’s still within the warranty period so you can contact the equipment installer or supplier.

Be ready with the serial number, fault name and code with a brief description of the fault. If your Sungrow KTL-M Solar Inverter is outside the warranty period we suggest that you contact a professional solar power expert. If you’re in the Gold Coast or Brisbane area contact Gold Coast Power Solutions here and we will be in touch to provide you with further assistance.

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