Open Ground Receptacles

One type of call I get often as an electrician in Phillipsburg, New Jersey and its surrounding areas is for open ground receptacles-that is when a receptacle has no equipment grounding conductor connected. This is commonly noted on inspection reports when a home is inspected by a representative of prospective buyers, or by a town inspector for a rental property.

This "open ground" condition is very common in older homes with older wiring methods such as Knob & Tube, Cloth insulated BX cable, or early Non-metallic cables. With the advent of modern NM cable (Romex) in the 1960's equipment grounding conductors became common and required from then on.

The equipment ground is important because it brings the normally non-energized metallic components of an electrical system to the same potential as earth-zero. Additionally, in the event of a fault, (such as an exposed piece of wire touching a copper water line) the equipment ground of that circuit would provide a low-resistance path back to the over current protection and trip the breaker. An un-grounded 2-wire system can't be trusted to do the same.

So, what's the problem? When 2-wire systems were installed up until the 1960's your receptacles only had 2 prongs, the "hot" and the "neutral" Modern plugs have 3, and the round prong in the middle below (or above) the hot and neutral is the equipment ground. The problem arises when 3 prong outlets have been installed on a 2-wire system, causing the open ground reading on a plug checker.

What is the Solution? There are multiple solutions available which i will list here on a ranked basis.

Not Recommended: Install the proper receptacle the system was intended to use; a 2 prong non-grounding type receptacle. The problem here is people will use "cheaters"- Anyone remember the 2 prong to 3 prong adapters? This creates the same hazard that existed before with the added hazard of a cheap adapter.

Minimum Acceptable: The code allows us to protect personnel using non-grounded 2-wire systems with GFCI's (Ground Fault Circuit Interrupter) These are the rectangular receptacles with test/reset buttons/ indicator light you are familiar with on your kitchen counters and bathrooms. We are able to identify the first receptacle in the circuit and protect the rest of the 3 prong receptacles without equipment ground from the load side of that GFCI receptacle. It is safe, but you end up with GFCI receptacles everywhere which can be unsightly. *

Better: Protect the whole circuit with a GFCI breaker. In this instance the whole circuit is protected from the last device all the way to the panel, and there are no unsightly GFCI's in your rooms. A caveat here is there are not always GFCI breakers available for some older legacy panels. *

*Note- The code requires stickers on the faceplates of GFCI protected 3 prong outlets without equipment ground that read "GFCI Protected-No Equipment Ground" which can be unsightly.

Best: Replace the wiring method with modern 3-wire NM cable. This method is of course the most expensive but ultimately the best and safest. This way your 3 prong outlets will have a proper equipment ground. No GFCI's to worry about, no stickers etc. This starts to make more sense if you're also looking at replacing wiring methods considered unsafe at this point anyway-such as Knob and Tube wiring.

If you are buying a home in Phillipsburg, New Jersey, Lopatcong, New Jersey, Stewartsville, New Jersey, Belvidere, New Jersey, Washington, New Jersey, Milford, New Jersey, or Bloomsbury, New Jersey and open ground receptacles comes up on your home inspection report, Call Mc Caffrey Electrical Contracting at (908) 818-0460 today.

Receptacle checker reading normal