Analysis: DC Input PV1 voltage low.  DC Input PV2 voltage low
Solution:
1. If it only happened in a bad weather (such as: in the evening or morning); but it’s normal at other times, so the failure probably be caused by the insufficient input power, this case is a normal phenomenon; Just wait for weather becoming better, the machine will automatically recover and generate power again, please ignore this situation.
2.Disconnect both of AC side and DC side switch, and unplug the Solar panel string from inverter one by one, to  check if the positive and negative of each string is wrong or opposite, and test if each string voltage is within inverter rated range.If the DC connection is correct, please restart the inverter and observe whether the inverter can normally return to work. 
3.Check if the inverter running mode be set correctly.
4.To exchange the 2 MPPT panel string and keep a further observation.

Analysis: Grid voltage too low
Solution: 
1. Check what the phase voltage is and frequency is from the display, check if they are in the rated range.
2. Check if AC terminal and distribution box internal connection is correct, check if any connection is loose or disconnected, check if the breaker in distribution box was tripped.
3. Use the multimeter to check if the grid connection is correct, and check if phase voltage and line voltage is too low
4. Check if the inverter’s safety code be set correctly and Grid under-voltage protection point be set to match actual situation.
5. Waiting for a while until grid voltage recovered, to observe on inverter and check if it can automatically return to normal running.

Analysis: Grid voltage too high
lSolution:
1. Check what the phase voltage is and frequency is from the display, check if they are in the rated range.
2. Check if AC terminal and distribution box internal connection is correct, check if any connection is loose or disconnected, check if the breaker in distribution box was tripped.
3. Use the multimeter to check if the grid connection is correct, and check if phase voltage and line voltage is too low
4. Check if the inverter’s safety code be set correctly and Grid under-voltage protection point be set to match actual situation.
5. Waiting for a while until grid voltage recovered, to observe on inverter and check if it can automatically return to normal running.

Analysis: Grid frequency too low
Soluition:
1. Check what the displayed AC frequency value is, check if the value is in the rated range.
2. Check if AC terminal and distribution box internal connection is correct, check if any connection is loose or disconnected, check if the breaker in distribution box was tripped.
3. Use a multimeter to see if the grid wire connection is correct ; check if the grid frequency is too low
4. Check if the inverter’s safety code be set correctly and Grid under-frequency point be set to match actual situation.
5. Please Wait for a while until the grid frequency recovered, then check if the inverter can return to normal
 

Analysis: Grid frequency too high
Solution:
1. Check what the displayed AC frequency value is, check if the value is in the rated range.
2. Use a multimeter to check if the grid connection is correct ; and check if the grid frequency is too high
3. Check if the inverter’s safety code be set correctly and Grid over-frequency protection point be set to match actual situation.
4. Please Wait for a while until the grid frequency recovered, then check if the inverter can return to normal

Analysis: The Inverter’s clock time be set to wrong or not set
Solution:
1. Check if the inverter’s clock be set correctly
2. Re-set the inverter’s clock through HMI or monitoring, check if the alarm is repeated. 

Analysis: The communication is faulty between combiner box and inverter
Solution: Check if the RS485 cable connection between DC combiner box and inverter is correct, whether It is loose or disconnected.

Analysis: DC input voltage is too high
Solution: 
1. Turn off the DC & AC Switch,  and disconnect the DC solar string one by one, then, use the multimeter to check if the polarity direction and voltage of each string is correct, make sure it is in the rated range.
2. Restart inverter( by disconnect DC&AC switch, wait for 5 mins, then turn it on), observe if it can return to normal running.

Analysis: Inverter internal BUS voltage over range
Solution: 
1. Check if the inverter’s DC side connection is correct, check if the DC voltage is in rated range
2. Restart inverter(disconnect DC&AC switch, wait for 5 mins, then turn it on), observe if it can return to normal running.
3. Check if the AC “N” and “PE” cable be connected well , and complied with the standard requirements

Analysis: Inverter has faulty on Boost circuit
Solution: 
1. If it only happened in a bad weather(such as: in the evening or morning); but other times are normal, so the problem probably be caused by the insufficient input power,  it’s a normal phenomenon; please wait for weather becoming better, the machine will automatically recover and generate power again, please ignore this situation.
2. Check if the inverter’s DC side connection is correct, check if the DC voltage is in rated range
3. Restart inverter (disconnect DC&AC switch, wait for 5 mins, then turn it on), observe if it can return to normal running.

Analysis: Inverter internal AC current output over range
Solution:
1. Check if the solar panel be configured too many. Check if total installed solar panel capacity is too high.
2. Check if there is a short-circuit in AC wire connection or in inverter AC terminal.
3. Restart inverter (disconnect DC&AC switch, wait for 5 mins, then turn it on), observe if it can return to normal running.
4. Observe if the grid Voltage is fluctuating too much.

Analysis: Inverter internal temperature is too high.
Solution: 
1. Check if the inverter Fan is working and running normally
2. Check if the inverter Fan is stuck by something
3. Check if the inverter be installed well and complying with standards requirement, and inspect whether the ventilation conditions is well or not
4. Check if the inverter is installed directly towards the sunshine, or has any heat producing appliances nearby.

Analysis:external system insulation Resistance  is too low
Solution: 
1. Check the wiring situation of DC side and solar panel, such as the existence of poor contact, cable damage and other phenomena; (can judge it by measuring the positive and negative voltage to the ground);
2. Check if inverter/ wire/ solar panel be located in a wet environment.
3. When In a dry environment, to restart inverter(disconnect DC&AC switch, wait for 5 mins, then turn it on), observe if it can return to normal running.

Analysis: The Communication is faulty between main DSP and slave 
Solution:
1. Restart inverter (by disconnect DC&AC switch, wait for 5 mins, then turn it on), observe if it can return to normal running
2. Replace the control board

Analysis: the current leakage of system or inverter is too high
Solution: 
1. Check if the wiring or connection of DC&AC side existed poor contact or wire damage phenomenon
2. Check if the ground wire connection are connected well among solar panels
3. Check if the inverter, wiring or solar panel is located in the very wet condition.
4. When In a dry environment, to restart inverter ( disconnect DC&AC switch, wait for 5 mins, then turn it on), observe if it can return to normal running.

Analysis: Inverter internal relay  is faulty
Solution: 
1. Make sure that the AC&DC connection is correct, especially pay attention to the “N” and “PE” cable , to check if their connection has been done well.
2. Restart inverter (disconnect DC&AC switch, wait for 5 mins, then turn it on), observe if it can return to normal running

Analysis: Inverter internal FAN is faulty
Solution: 
1. Inspect if the FAN cover plate is deformed
2. Observe if the FAN can normally running( judge it by hearing the running sound or use a hand to feel the wind status)
3. Disconnect the both of AC and DC side switch, after 5 minutes, to check if the FAN connection wire is loose
4. Replace the faulty fan, and observe if inverter can return to normal

Analysis: DC composition is too high in AC Output
Solution: Restart inverter (Disconnect DC&AC switch, wait for 5 minutes, then turn it on), observe if it can return to normal running

Analysis: Output AC short circuit
Solution: 
1. Check if the AC cable/wires, or grid components is grounded, or short circuit.
2. Restart inverter (Disconnect DC&AC switch, wait for 5 minutes, then turn it on), observe if it can return to normal running

Analysis:DC input over current
Solution: 
1. Check if the solar panel be configured too many, or installed power capacity is too much.
2. Restart inverter (Disconnect DC&AC switch, wait for 5 minutes, then turn it on), observe if it can return to normal running

Analysis: The detected grid voltage/frequency/leakage current, or DC composition is inconsistent between main and slave DSP.
Solution: Restart inverter (Disconnect DC&AC switch, wait for 5 minutes, then turn it on), observe if it can return to normal running.