SolarEdge – Error Code 77

SolarEdge – Error Code 77

Is your SolarEdge Solar Inverter showing up with Error Code 77 on the screen?

What is a SolarEdge Error Code 77?

Ground Current – RCD

Recommended solution/fix steps

Ground faults may occur due to insufficient insulation to the ground. ELECTRICAL SHOCK HAZARD. Do not touch uninsulated wires
when the inverter cover is removed. Only a qualified technician should handle this problem, and only after taking proper
precautions.
1. Turn the inverter ON/OFF switch to OFF.
2. Wait five minutes for the input capacitors to discharge.
3. Disconnect the AC breaker.
4. Disconnect the DC inputs.
5. Connect each DC string separately, turn the AC and the inverter ON/OFF switch to
ON, until the error appears for the faulty string.
Do not connect strings with a grounding fault to the inverter. A certified installer must
fix the faulty string before connecting it to the inverter

Troubleshooting to try

• Check if your inverter is switched on
• Check if your DC isolator is turned on
• Check if all the light indicators are green
• Try rebooting the whole system

How to restart/reset/reboot your SolarEdge solar inverter?

Follow the inverter shut down procedure label which may be located on your inverter or the main switchboard of your house.

Typically, this procedure will be:

1. Turn off the AC “Solar Supply Main Switch” or “Inverter Main Switch” located on the main switchboard of the house.
2. Turn off the AC isolator at the inverter (if present)
3. Turn off the “PV array DC isolator”, located next to the inverter. The screen should go blank, and the lights should go off.  Leave it like this for five minutes or so, and then switch it back on.
4. Wait a few minutes…
5. Turn the inverter back in reverse order (DC isolator first, AC second).
6. DC On first. It is very important that you restart by switching the DC isolator on first, as you shouldn’t switch DC under load (ie with the AC on), as the isolator could arc.
7. AC On next. Put the AC switch (solar supply main switch) back on, and then wait.  All inverters take at least one minute to restart, and you may see the lights flashing while the inverter does internal testing.  There will also be a variety of messages on the screen again as it tests.  This is quite normal.

SolarEdge Maintenance

Regular maintenance ensures a long operating life and optimal efficiency of the entire PV plant. Risk of inverter damage or personal injury due to incorrect service! Always keep in mind that the inverter is powered by dual sources: PV strings and utility grid.

Before any service work, observe the following procedure:

• Disconnect the AC circuit breaker and then set the DC load-break switch if the inverter to OFF;
• Wait at least 10 minutes for inner capacitors to discharge completely;
• Verify that there is no voltage or current before pulling any connector.

Maintenance Items include:

• If the inverter is dirty, clean the enclosure, the enclosure lid, the type label and the LEDs using only clean water and a cloth.
• Ensure that the inverter is free of dust, foliage and other dirt.
• At least once a year, open the fan screen and clean the accumulated dust using a brush.