Yes. The ground indicator light should be illuminated. If the light is not illuminated, there is a problem with the AC outlet into which the CyberPower surge suppressor is plugged. If this is the case, please disconnect the surge suppressor until the problem is resolved. The problem must be resolved before the CyberPower surge suppressor can be used.
Common issues with an AC outlet include: bad ground, missed ground, or reversed wiring (usually due to sub-standard wiring, typical in residential housing built prior to 1980). You may need to contact a qualified electrician to repair/upgrade the outlet.
NOTE: Using the CyberPower surge suppressor when the ground indicator light is not illuminated will void the warranty.