SMA fault guides
Plain answers to the fault codes and alerts we see most often on solar systems, with what our own monitoring and service records show.
- SMA event 1302 waiting for grid voltage: what it means and what to do
SMA event 1302 appears with the messages "Waiting for grid voltage", "Grid connection installation failure" and "Check grid and fuses". SMA explains that either a line or the neutral conductor is not connected, or the utility grid has failed. If the power is out in your area, the inverter waits for feed-in conditions to be met and starts feeding in again once they are; if your home has power and 1302 stays on, a technician needs to check the AC side.
- SMA event 3501 insulation failure: what it means and what to do
SMA event 3501 means the inverter has detected a ground fault in the solar array. Sunny Boy TL-US models show "Insulation resist." with "Check generator"; newer -US models show "Insulation failure" with "Check generator". SMA explains that the electrical insulation between the PV system and ground is defective or insufficient, and its corrective step, checking the system for ground faults, is for a qualified person. Do not touch the panels or racking, and book a technician.
- SMA event 4301 electric arc detected: what it means and what to do
SMA event 4301 means the inverter's arc-fault circuit interrupter (AFCI) has detected an electric arc in the solar (DC) wiring and has stopped feeding power. Older Sunny Boy TL-US models show "Electr. arc detected" with "Check generator"; newer -US models show "Serial el.arc in String ... detected by AFCI mod.", often naming the affected string. SMA treats the fix as work for a qualified person: the system is shut down and the panels, cables and connections are checked for damage. Leave the system as it is and book a technician.
- SMA event 7702 Interference device: what it means and what to do
On SMA Sunny Boy TL-US inverters, event 7702, like the whole range 7701 to 7712, appears as "Self diagnosis" with "Interference device". SMA's manual says the cause must be determined by the SMA Service Line, and its only corrective measure is to contact SMA. There is nothing for an owner to reset, so note the code and book a technician who can work through the case with SMA.
- SMA event 8206 electric arc detected: what it means and what to do
SMA event 8206 "Electr. arc detected" means the inverter has detected an electric arc and will not feed power until someone confirms that any damage has been repaired. On Sunny Boy TL-US models the display adds "Please confirm by tapping"; on newer -US models SMA calls this state operation inhibition. Confirming is meant to come after a qualified person has inspected the panels, DC wiring and connectors, so do not tap the inverter or reset it yourself.