EG4 › Problems
EG4 rapid shutdown trips by itself or cuts more than expected
Your EG4 system goes into rapid shutdown by itself, or the shutdown cuts more than you expected, such as the batteries and your backed-up loads. This page covers what the codes mean, what to check first, and the causes behind it.
Error codes that go with this problem
| Code | What it means |
|---|---|
| Flashing hybrid, no grid (GridBOSS or FlexBOSS21 display) | Shown right after the external rapid shutdown switch was pressed: all lights out, no grid detected, and the batteries in fault. |
| Error fault grid boss breaker open (app) | The FlexBOSS breaker inside the GridBOSS is open. It had been bumped open during rapid shutdown testing; it was not a GridBOSS fault. |
What to check first
- Note what the display and app show after the shutdown, such as flashing hybrid, no grid, or a grid boss breaker open message.
- Note what happened just before: a press of the shutdown button, the system powering up, or a battery comm cable being plugged in.
- After a rapid shutdown, reset the battery breakers by hand and power-cycle the batteries. The battery's reset button alone does nothing.
- If the system keeps going into rapid shutdown by itself, at power-up, or when a battery cable is plugged in, it needs a technician to check the rapid shutdown wiring and the battery comm cable.
Safety. After a rapid shutdown, the panel that is not backed up can still have 240 volts on it while the backed-up panel reads 0.
The causes and the fixes
Partners see the causes behind this problem, most common first, the checks that tell them apart, and the fix for each, with part numbers and recent prices when a part is involved.