No ground reference means little for the protector to divert into, so protection is compromised regardless of MOV condition.
Stop and call a licensed electrician or emergency services now if there's smoke, sparks, a burning smell, heat, shock, or water near the problem. Otherwise it's safe to answer the questions below.
The likely readout
Most likely cause
No ground at the outlet — surge protection has little to divert into and is largely ineffective until the receptacle is properly grounded
Ranked by fit to your answers
1
No ground at the outlet — surge protection has little to divert into and is largely ineffective until the receptacle is properly grounded
70
2
Protection appears active — the indicator reports the internal MOVs are still intact
55
SAFE NEXT CHECKPlug a tester into the same receptacle: if it shows an open ground, the protection has no diversion path. Have the outlet's ground verified before trusting the strip.
Where to stop. Swapping a plug-in surge strip is homeowner-safe. If the "Grounded" light is off, the receptacle itself may be ungrounded or miswired — confirm with a plug-in tester, and because correcting house wiring means live conductors, if a tester shows an open ground have a licensed electrician verify the outlet. This is general information, not a quote and not a substitute for a licensed electrician.
Try the safe next check above. If it doesn't resolve it, or would mean working on wiring or a panel, stop and call a licensed electrician — don't replace parts on a guess. Open the full tool to change any answer for your exact situation, or try a related check below.
source-governed · verified 2026-06-20
Sources
standard UL 1449 — Standard for Surge Protective Devices · verified 2026-06-20
Electrical Fault Check provides general diagnostic information only. It is not professional advice, not a quote, and not a substitute for a licensed electrician. Do not work on live wiring. If you see smoke, sparks, burning smell, heat, shock, water exposure, or repeated tripping, stop using the circuit and contact a licensed electrician or emergency services as appropriate.