I have an ungrounded circuit in my house with three-wire grounded receptacles. If I install a GFCI, will the downstream receptacles be protected even if the GFCI is ungrounded?

1 Answer 1


Absolutely, as long as you place the load wires going to the downstream receptacles onto the LOAD terminals of the GFCI receptacle.

A GFI does NOT need an equipment grounding conductor to function properly. In fact, using a GFI at the beginning of the circuit is what will allow you to legally and safely use 3-prong receptacles downstream. Thing is, this does not create an equipment ground for equipment protection for things such as surge suppressors.

By code you are supposed to label any non-grounding downstream receptacles "No equipment ground present".

  • Is there a limit to the number of receptacles protected by a single GFI? Commented Sep 6, 2015 at 13:09
  • From checking various seemingly reputable online sources, as well as checking my Leviton GFCI, it seems there is no limit on the number of outlets you can protect. Bonus advice: the cheap GFCI testers won't trip the GFCI if they're not grounded. I thought I got a bad GFCI until I realized this. Commented Sep 7, 2015 at 1:43
  • 1
    There is no limit technically. We typically limit load side devices to 5-6. Every device will have a tiny amount of leakage, so with too many on the load side there is an increased chance of nuisance tripping. Commented Sep 7, 2015 at 18:05

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service and acknowledge you have read our privacy policy.

Not the answer you're looking for? Browse other questions tagged or ask your own question.