Historically, if the Green LED indicator on your AG3000/PS3000 SPD was illuminated (ON), it meant that the surge protective device (SPD) was operating correctly. However, if the Green LED indicator was not illuminated (OFF), it meant the SPD had diminished protection, and the unit needed to be replaced.

We’ve recently updated these models to include a new Red LED indicator that turns ON when the device needs to be serviced. In short, if you see a Red LED indicator (or no light at all) on your AG3000/PS3000, the SPD has diminished protection and needs to be replaced. These updated models still include a Green LED indicator that will be illuminated when the device is working properly.