Generac PWRcell › Problems
Generac PWRcell solar production is low or has stopped
A Generac PWRcell system makes less solar power than expected, or none at all. This page covers what the inverter lights and the states on its screen mean, what to check first, and the causes behind it.
What the lights mean
| What you see | What it means |
|---|---|
| Inverter light blinking yellow | The inverter is waiting to connect to the grid, connecting to REbus, or waiting to connect to REbus. |
| Inverter light solid yellow | The inverter is disabled or powering up. |
| Inverter light red | The inverter is overloaded or has a serious fault. Someone likely has to step in before it runs again. |
| Inverter light green | The utility is connected and its voltage and frequency are normal. |
| Inverter light off | The inverter is powered down. |
| REbus light green | All devices on REbus are enabled and working normally. A PV Link can still show Waiting while this light is green. |
| REbus light yellow | One or more devices are disabled, or no devices are detected. |
| REbus light red | A serious fault has been found on a device or on the REbus wiring. |
Error codes that go with this problem
| Code | What it means |
|---|---|
| Inverter shows Waiting, Standby or Low REbus Voltage | The inverter has not connected to the grid. Not an error. Expected for 5 minutes after the system is first set up or after a grid outage; otherwise usually a problem with the AC power. |
| Pattern lockout | On inverter firmware 13853 this alternates with REbus under-voltage events during the 5 minute wait before the inverter connects to the grid. Later firmware shows Waiting instead. |
| PV Link shows Waiting | The PV Link is connected but not producing. Not an error. Expected when the inverter is already at its 7600 W maximum or an export setting is holding output back. |
| PV Link shows Low Sun | The PV Link is not seeing enough input voltage to start. Normal at night; a fault when it shows while the sun is shining. |
| PVRSS Lockout, State Code 7310 | The PV Link's daily safety count of the SnapRS rapid-shutdown devices on its string has failed. |
| PVRS mismatch | The number of SnapRS set as installed in the PV Link's settings does not match the number it detects on the string. Seen after SnapRS were replaced. |
| CTCAL message after CT calibration | CTCAL Success means the CT calibration worked. Any other CTCAL message is a calibration fault, listed in the inverter install manual's CT troubleshooting table. |
What to check first
- Look at the inverter's status lights and its screen, and note what they show for the inverter and for each PV Link.
- If the system was just set up or the power just came back, wait 5 minutes. The inverter waits that long before it connects to the grid.
- A PV Link showing Low Sun at night is normal.
- Check the inverter's output on its screen. At 7600 W or more the inverter is at its maximum, and PV Links showing Waiting need no action.
- A red inverter light means an overload or a serious fault, and someone likely has to step in before it runs again. A red REbus light means a serious fault on a device or the REbus wiring.
- Call your installer if the inverter has not connected after 5 minutes, a PV Link shows Low Sun in daylight, or the inverter light is red. Generac also has a 24-hour support line by phone or email.
Safety. Before anyone works in the solar array, the system has to be disabled and a meter used to confirm no voltage is present. The inverter restart sequence is for trained, certified people.
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.